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Science Science 6

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CONTENTSNo. Unit Name Page

Unit 1 What is Science? 3

Unit 2 Cellular Organization of Plants and Animals

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Unit 3 Our Sense Organs 15

Unit 4 How Plants Stay Alive 20

Unit 5 Living Things and their Environment 26

Unit 6 The Hidden Structure of Matter 31

Unit 7 Air 39

Unit 8 Solutions, Suspensions and colloids 46

Unit 9 Introduction to Energy and its Forms 53

Unit 10 Putting Energy to Work: Machines 59

Unit 11 Behaviour of Light 64

Unit 12 Sound Around Us 75

Unit 13 Exploring Space 79

Skylark Science 6 Key Book

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Unit 1

What is Science?Section Review I

Q1. What is science?Ans: Science is a knowledge which is gained through

observation and experimentation.Q2. Who is a scientist?Ans: A man who adopts studying science as a career is

called a scientist.Q3. How does a scientist solve a problem?Ans:Ascientistusesscientificmethodtosolveaproblem.Q4. What are observations?Ans: Anything which you notice about the problem is

called an observation.Q5. How does a scientist test his/her hypothesis?Ans: Scientists test their hypotheses by doing experiments.Q6. What do you mean by data?Ans: Data are observations from an experiment.

Section Review II

Q1. Where does a scientist work safely?Ans: A scientist works safely in a science laboratory.Q2. Name the following laboratory equipment.

Mortar and pestle

Bunsenburner

Tripodstand

Measuringcylinder

Ans:


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Q3. Who is the father of chemistry?Ans: Jabar Bin Hayyan is the father of chemistry.Q4. Who invented a Pin-hole camera?Ans: Ibn-Al-Haitham invented a Pin-hole camera.Q5. Who presented “Laws of motion”?Ans: Isaac Newton presented “Law of motion”.Q6. Who invented the telescope?Ans: Galileo Galilei invented the telescope.

Unit Review

Science Words Medical science scientist hypothesis equipment Complete each of following sentences with the

words given above that will make the sentence correct.

1. A __________ is a possible answer to the problem.2. You will use different pieces of __________ in the

science laboratory.3. Scientific researches in_________have improved

human health.4. A person who adopts studying science as a career is

called a __________.

Answer: 1. hypothesis 2. equipment 3. Medical science 4. scientist


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Multiple Choice Questions Encircle the letter of the best answer.1. Science is bad, due to this reason: (a) improve health (b) explore space (c) make bombs and warheads (d) increase crops’ production2. The question you want to answer is your: (a) hypothesis (b) experiment (c) problem (d) conclusion3. By making conclusions, you decide wether your: (a) hypothesis is correct (b) experiment is correct (c) problem statement is correct (d) data is correct4. Sulphuric acid, nitric acid and hydrochloric acid

were prepared by: (a) Ibn-Al-Haitham (b) Al-Bairuni (c) Jabar Bin Hayyan (d) Bu Ali Sina5. Calculated the radius of the earth for the first

time: (a) Al-Bairuni (b) Dr. Abdus-Salam (c) Al-Haitham (d) Galileo

Answer: 1. (c) 2. (c) 3. (a) 4. (c) 5. (a)


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Detailed-Answer QuestionsQ1. Give arguments to prove that science is good not

bad.Ans: Science is Good: Science has made our lives easier

andcomfortable. It helpsus inmanyfieldsofoureveryday life.i Science and Agriculture

Science has helped farmers to increase the production of crops. Now, we use tractors, harvesters, threshers, insecticides and fertilizers to increase the production of crops.

ii. Science and our HealthScience has enabled us to diagnose and treat many of our diseases. Ultrasound, X-ray, E.C.G, E.E.G and Gastroscopy etc. are modern scientifictechniques.

iii. Science and TransportationScience has made it possible to cover long distance in very short time. Now, we use cars, buses, aeroplanes and jet planes to move from one place to the other.

iv. Science and CommunicationModern communication in the form of mobile, e-mail, fax and internet has revolutionized the field.

Q2. Writethestepsofscientificmethod.Ans: Scientific Method: Scientific method helps

scientists to solve our everyday problems. Here are


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thestepsofscientificmethod.i Identifying the Problem: First of all scientists

identify the problem to be solved.ii. Making Observations: Scientists collect

everything they notice about the scientificproblem. In this way, they gather observations.

iii. Hypothesis: Scientists suggest a possible solution to the problem. It is called hypothesis.

iv. Experimentation: Scientists test a hypothesis through experiments.

v. Collecting Data: Scientists collect observations about experiments. It is called data collection.

vi. Conclusion: Scientists decide about the hypothesis whether, it is correct or not.

Inthisway,theysolveascientificproblem.Q3. Briefly describe the contributions of following

scientists; 1. Jabar Bin Hayan 2. Isaac Newton 3. Al-HaithamAns: Jabar Bin Hayan: This great Muslim scientist is

said to be the “Father of Chemistry”i. Jabar has his own laboratory.ii. He knows the methods of making steel, leather,

dying the cloth, and making varnish.iii. He prepared sulphuric acid, nitric acid and

hydrochloric acid in his laboratory.iv. He also wrote many books on science.

Isaac Newton: Isaac Newton was a great English


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scientist.i. He Presented his famous “Laws of Motion”,

“Law of Gravitation” and “Principles of the Calculus”.

ii. He also discovered the seven colours of light. Al-Haitham: Al-Haitham is a great Muslim

Scientist.i. Hediscovered“Inertia”forthefirsttime.ii. He invented “Pinhole Camera”.iii. He wrote the structure of human eye in his book.iv. Healsodiscussedmirrors,lenses,reflectionand

refraction of light.Q4. Which safety rules should be followed while

working in a science laboratory?Ans: Safety Rules in Science Laboratory

i. Work in the laboratory under the supervision of your science teacher.

ii. Don’t eat in the laboratory.iii. Never taste chemicals, they may be poisonous.iv. Immediately report to your teacher in case of

any accident.v. Never run in the laboratory.vi. Clean the apparatus after finishing the

experiment.


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Unit 2Cellular Organization of

Plants and AnimalsSection Review I

Q1. What is the function of microscope?Ans: A microscope helps to see things that our eyes

cannot see. We can see very small objects by using a microscope. The word “micro” means very small.

Q2. Why is the nucleus called the control centre of the cell?

Ans: The nucleus controls all the activities of a cell. That is why, it is called its control centre.

Q3. What is the cytoplasm? What is it like?Ans: The part of a cell between the cell membrane and

the nucleus is called cytoplasm. It is a transparent, jelly-like material. Cell organelles are present in the cytoplasm.

Q4. Who discovered the cell?Ans: Robert Hooke discovered the cell. He was an English

scientist.Q5. How many times does an electron microscope

magnify the image of an object?Ans: An electron microscope can magnify the image up

to 500,000 times.

Section Review II

Q1. How does an amoeba move?


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Ans: An amoeba moves by moving its cytoplasmic foot called pseudopodium.

Q2. Which food does an amoeba use?Ans: It feeds on very small organisms and food particles.Q3. Why is chlamydomonas considered a plant?Ans. A chlamydomonas has chloroplast to make its own

food. That is why, it is considered as a plant.Q4. Which unicellular organism has the

characteristics of animals and plants?Ans. Euglena is a unicellular organism that has the

characteristics of animals and plants.Q5. Which organelles does an animal cell lack as

compared to the plant cell?Ans. An animal cell lacks cell wall, chloroplast and a

large vacuole that are present in a plant cell.

Section Review III

Q1. What is a cell?Ans. A cell is the basic unit of all living things.Q2. Defineatissue.Ans. A group of similar cells that perform the same

function is called a tissue.Q3. What is an organ?Ans. An organ is made up of different tissues that work

together.Q4. What are the functions of root system in a plant?Ans.Roots fix the plant in the soil. Roots also absorb

water as minerals from the soil.Q5. Which system conducts messages in your body?Ans. The nervous system conducts messages in our body.


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Unit Review

Science Words nucleus organ an organ system

unicellular organism multicellular Complete each of the following sentences with

the words given above. 1. An ____________ is a group of different tissues

which work together.2. _________ is the brain of the cell which controls its

functions.3. A ____________ organism consists of several cells.4. A one-celled organism is called ____________.5. A group of different organs working together to

perform certain function is called ____.

Answer: 1. organ 2. nucleus 3. multicellular 4. unicellular organism 5. an organ system

Multiple Choice Questions1. All living material in a cell is called the: (a) nucleoplasm (b) cell sap (c) protoplasm (d) cell’s solution2. The food making structures in green plant cells

are the: (a) vacuoles (b) mitochondria (c) Golgi bodies (d) chloroplasts3. The ‘power houses' of the cell are: (a) chloroplasts (b) mitochondria


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(c) Golgi bodies (d) chromosomes4. Heart, liver and ears are examples of animal: (a) organs (b) tissues (c) cells (d) organ systems5. Wastes of the body are removed through: (a) circulatory system (b) excretory system (c) digestive system (d) nervous system

Answer: 1. (c) 2. (d) 3. (b) 4. (a) 5. (b)

Detailed-Answer QuestionsQ1. Describe parts and functioning of a compound

microscope.Ans. Microscope A microscope is an instrument that is used to see

very small objects. Parts of a Microscope A microscope has a base, an arm, a tube, a stage

andtwoadjustmentscrews.Twolensesarefittedonthe two ends of the tube. One end is called eyepiece and the other is called objective. We look through the eyepiece. A mirror throws light to help see the object.

The object to be seen is placed on the stage. While looking through the eyepiece, we can focus the objects using adjustment screws.

Q2. Describe the structure of a plant cell.Ans. A Plant Cell Plants are also made of cells. But, a plant cell is bit

different from an animal cell.


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A plant cell has following parts:i. Cell Wall is present on the outer side of the

plant cell. It is made of cellulose. It gives shape to the plant cell.

ii. Cell Membrane is present beneath the cell wall. It controls the transport of materials in and out of the cell.

iii. Cytoplasm is the jelly like material that is present between cell membrane and nucleus. Cell organelles such as, endoplasmic reticulum, mitochondria, chloroplasts and vacuoles are present in the cytoplasm.

iv. Nucleus of a plant cell is most important part of the cell. It is surrounded by nuclear membrane. The nucleus controls almost all the activities of cell.

Q3. Write a note on amoeba.Ans. Ameoba An amoeba is a unicellular organism. This animal

is only visible under a microscope. It is found in water.Amoeba has no fixed shape. Its cytoplasmflowmove inanydirection tohelpamoebamove.Nucleus, vacuoles and other organelles are present in the cytoplasm of amoeba. Amoeba moves with the help of pseudopodia. It feeds on very small organisms and food particles. It can be divided into new daughter amoebae.

Q4. Write about shoot system of a plant.Ans. Shoot system of a Plant The aerial parts of a plant makes the shoot system. It


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consistsofmainstem,leaves,branchesandflowers.Leaves make food for the plant. Flowers produce seeds. Seeds grow into new plants.

Q5. Writebrieflythepartsandfunctionsof: i. Nervous System ii. Circulatory SystemAns. i. Nervous System Brain, spinal cord and nerves are the parts of nervous

system. This system controls our body parts. It sends and receives messages from different parts of the body.

ii. Circulatory System Heart, arteries, veins and capillaries are the main

parts of the circulatory system. This system carries oxygen and food to all parts

of our body. It also brings wastes to the excretory organs to remove from the body.


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Unit 3Our Sense Organs

Section Review I

Q1. About which things do your eyes tell you?Ans. Our eyes tell us about the things that are happening

around us.Q2. Name the outermost and innermost layers of the

eye.Ans. The outermost layer of the eye is called sclerotic.

The innermost layer of the eye is retina.Q3. Why should one not read in poor light?Ans. Reading in poor light can harm our eyes. It causes

theretinacellstoexpandandeyelenslessflexible.Q4. Which part of our ear receives sound waves?Ans. The pinna collects the sound waves from the air. The

pinna is the part of outer ear.Q5. How is balance of your body maintained?Ans. Three semi-circular canals present in the inner ear

maintain our body balance.Q6. Name three bones of the middle ear. Ans. Hammer, anvil and stirrup are the bones of the

middle ear.Section Review II

Q1. What is the function of the inner layer of your skin?

Ans. The inner layer of the skin is very sensitive. When we touch something, sensitive cells of the skin


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receive messages and send them to the brain.Q2. What is pain?Ans. When nerves are damaged or pressed hard, we feel

pain. Nerves carry message of pain to the brain.Q3. How does our nose function?Ans. When certain odour chemicals present in air enter

our nose, the sense cells for smell receive message. These cells send the message of smell to the brain via olfactory nerve.

Q4. Why does your sense of smell become poor, when you smell a certain odour for quite a long time?

Ans. When we smell a certain odour for quite a long time, our sense of smell becomes poor because the nerve cells in our nose get fatigued.

Q5. How do your tongue feel different tastes?Ans. Different parts of our tongue are sensitive to different

tastes. The tip of the tongue can identify sweet taste. Sides are sensitive to salty and sour taste. The back of the tongue can identify bitter taste.

Q6. What happens to the sense of taste, when you have a bad cold?

Ans. When we have a bad cold, our sense of taste also disturbs. It is because both of the senses that is the smell of taste and the sense of smell are closely related.

Unit Review

Science Words anvil pupil auditory nerve taste buds body balance


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Complete each of the following sentences with the words given above.

1. __________ is the hole in the middle of the iris.2. Second bone of the middle ear is _________.3. About 8000 ________ are scattered on your tongue.4. _________ carries signals from ear to brain.5. Three semi-circular canals of inner ear help to

maintain your _________.

Answer: 1. pupil 2. anvil 3. taste buds 4. auditory nerve 5. body balance

Multiple Choice Questions Circle the letter of the best answer.1. The control room of your body is: (a) heart (b) stomach (c) brain (d) liver2. Which sense organ tells you about pressure? (a) ear (b) tongue (c) nose (d) skin3. The sides of your tongue are sensitive for: (a) salty and sour tastes (b) sour and sweet tastes (c) sweet taste (d) bitter taste4. Which cells of retina in your eyes are stimulated

in bright light? (a) cone cells (b) rod cells (c)roundcells (d)flatcells5. The liquid present between the lens and retina of

your eye is:


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(a) vitreous humour (b) aqueous humour (c) water (d) salt solution6. When nerves are damaged or pressed hard, you

feel: (a) cold (b) hot (c) pain (d) strange

Answer: 1. (c) 2. (d) 3.(a) 4. (a) 5. (a) 6. (c)

Detailed-Answer QuestionsQ1. Describe the structure of human eye.Ans. Human Eye Our eye is made up of three layers:

i. Sclerotic is the outermost layer. It is tough, white and opaque. In the front of eye, sclerotic is transparent. This part is called cornea.

ii. Choroid is present beneath sclera. Behind cornea, there is iris. It is the coloured part of the eye. There is a hole in the iris called pupil. Behindpupilthereisflexiblelens.

iii. Retina is the innermost layer of eye. Lens forms image on retina. Optic nerve is attached to the retina. It carries message of sight to the brain.

Q2. Describe the structure and function of inner ear.Ans. The structure and Function of inner Ear The last part of the human ear is the inner ear. It is

filledwithaliquid.Thereisacoiledcochleaintheinner ear. The cochlea is the actual hearing organ. The sound waves cause the liquid and hair-like cells


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of cochlea to vibrate. Auditory nerve attached to the cochlea carries signals to the brain to hear sound. Three semi-circular canals in the inner ear maintain body balance.

Q3. Write a note on the sense of smell.Ans. Sense of smell Our nose gives us our sense of smell. Our nose

is divided into two nostrils. In each nostril, an air chamber is present. The roof of chambers has lining of nerve cells. When certain odour chemicals present in air touch the hairs of nerve cells, olfactory nerve picks and carries signals about the type of smell.

Identify and Label Identify and label the following diagram.Ans. Internal Structure of Human Ear

Pinna

earcanaleardrum

cochlea

Semi circular canals


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Unit 4How Plants Stay Alive

Section Review I

Q1. From where do plants get energy?Ans. Plants get energy from sunlight.Q2. What functions does epidermis perform in the

leaf?Ans. The upper epidermis allows sunlight to enter the

cells of the leaf. The lower epidermis allows gases (oxygen and carbon dioxide) to exchange. It also allows to release water from plants.

Q3. Why is chlorophyll important for a plant?Ans. Chlorophyll traps sunlight energy and use it to make

glucose from carbon dioxide and water.Q4. Which tissues of plants are responsible for the

conduction of water from roots to the leaves?Ans. Xylem tissues in plants are responsible for the

conduction of water from roots to the leaves.

Section Review II

Q1. Definephotosynthesis.Ans. Photosynthesis is the process in which plants make

their food by using carbon dioxide and water in the presence of chlorophyll and sunlight.

Q2. Write the word equation for photosynthesis.Ans. Carbon dioxide+water Sunlight

Chlorophyll Glucose+Oxygen

Q3. From where do plants get water for


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photosynthesis?Ans. Plants absorb water from soil through their roots and

use it in photosynthesis.Q4. Which are the products of photosynthesis?Ans. Glucose and oxygen are the products of

photosynthesis.

Section Review III

Q1. Which surface of leaf contains more stomata?Ans. The lower epidermis of a leaf contains more stomata.Q2. Definerespiration.Ans. Respiration is the energy producing process in which

living organisms use oxygen and glucose to produce energy. Carbon dioxide and water are produced as waste materials during this process.

Q3. Why do plants release carbon dioxide during night time and not during the daytime?

Ans. During day carbon dioxide, produced during respiration, is used in the process of photosynthesis. At night, as photosynthesis stops, the carbon dioxide, produced during respiration, is released out of a plant’s body.

Q4. Which gas is used during respiration?Ans. Oxygen gas is used during respiration.

Unit Review

Science Words epidermis phloem photosynthesis greenhouse chlorophyll respiration


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1. ________ is responsible for the conduction of prepared food in plants.

2. During ________, energy is produced by using glucose and oxygen.

3. The outer protective layer of the leaf is called _________.

4. Plants use water and carbon dioxide to make food in the process of _________.

5. The green pigment in plants is called __________.6. Carbon dioxide, water and light are provided

properly and suitable temperature is maintained in the environment of a ___________.

Answer: 1. phloem 2. respiration 3. epidermis 4. photosynthesis 5. chlorophyll 6. greenhouse

Multiple Choice Questions Circle the letter of the best answer.1. Stomata are found abundantly in: (a) lower epidermis of a leaf (b) upper epidermis of a leaf (c) stem (d) roots2. Xylem vessels conduct: (a) food (b) water (c) sunlight (d) chlorophyll3. Photosynthesis is a combination of two: (a) English words (b) Latin words (c) Arabic words (d) Greek words


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4. Exchange of gases takes place through: (a) stomata of leaf (b) xylem vessels (c) phloem cells (d) mesophyll tissues5. Products of photosynthesis are: (a) carbon dioxide and water (b) hydrogen and water (c) glucose and carbon dioxide (d) glucose and oxygen6. During respiration organisms release a gas: (a) oxygen (b) nitrogen (c) carbon monoxide (d) carbon dioxide7. All animals and plants respire in: (a) carbon dioxide (b) oxygen (c) nitrogen (d) hydrogen

Answer: 1. (a) 2. (b) 3. (d) 4. (a) 5. (d) 6. (d) 7. (b)

Detailed-Answer QuestionsQ1. Describe the internal structure of a leaf.Ans. Internal Structure of a Leaf Leaves are the food factories for plants. A leaf

contains three main parts.i. Epidermis: Epidermis is the outer protective

layer of a leaf. The upper epidermis has a waxy layer to reduce the loss of water. It allows sunlight to enter the leaf. The lower epidermis has openings called stomata. Stomata help in exchange of gases.


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ii. Mesophyll: Mesophyll is the green part of a leaf. Chlorophyll is present in mesophyll. Here, cells make food using chlorophyll, sunlight, water and carbon dioxide.

iii. Vascular Bundles: Xylem and phloem tissues form the vascular bundle. It is present in the centre of a leaf. Xylem helps to move water and phloem helps in the movement of food from one place to the other.

Q2. Which factors are necessary for photosynthesis?Ans. Factors involved in Photosynthesis Following are the necessary factors for

photosynthesis.i. Light: Plants trap energy of sunlight to make

food. Photosynthesis increases as the light intensity increases.

ii. Carbon Dioxide: Plants use carbon dioxide to make food. They absorb it from air.

iii. Water: Water is also used to make food in plants. Plants absorb water from the soil.

iv. Chlorophyll: This green pigment in plants traps sunlight energy and use it to make food.

v. Temperature: The higher the temperature, the faster the process of photosynthesis. Normally plants grow well at 25-35°C.

Q3. Prove that the structure of a leaf facilitates the process of photosynthesis.

Ans. Structure of a Leaf and Photosynthesis Mostly photosynthesis occurs in leaves because:


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i. They have flat blade to absorb maximumsunlight.

ii. Their thin structure helps to absorb carbon dioxide from the air.

iii. A large number of stomata facilitates the exchange of gases and water vapour.

iv. Xylem and phloem tissues in veins and midrib help move water and prepared food.

Q4. How does respiration occur in plants?Ans. Respiration in Plants Respiration is the energy producing process in

plants. Plants use oxygen and glucose to produce energy. Carbon dioxide and water are also produced in this process.

Glucose+Oxygen Carbon dioxide+Water +Energy

During the day, plants use oxygen produced in the process of photosynthesis. At night, they absorb oxygen from the air to use in respiration. Carbon dioxide and water are used within the plant body in food making process.


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Unit 5Living Things and Their

EnvironmentSection Review I

Q1. Howwouldyoudefinetheword“environment”?Ans. Everything around an organism that affects or may

affect its life is called its environment.Q2. Which are abiotic components of environment?Ans. Soil, water, air, sunlight and temperature are the

abiotic components of environment.Q3. Why are plants called producers?Ans. Plants use water, carbon dioxide, sunlight and

chlorophyll to make their food. This food is also used by other animals too. That is why, plants are called producers.

Q4. Write three needs of animals for which they depend upon plants?

Ans. 1. For food. 2. For oxygen 3. For shelterQ5. What is a food chain?Ans. A food link between organisms is called a food

chain, e.g. grass eaten by cow eaten by humans

Section Review II

Q1. How does light affect lives of plants and animals in an environment?


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Ans. Light is the source of energy on Earth. Plants use sunlight energy to make food. This food is also used by all other organisms.

Q2. What is a prey?Ans. The animal which is killed by a predator or hunter is

called a prey.Q3. In which areas of the world is life in abundance?Ans. Living organisms are abundant in those areas of the

world where water is easily available.Q4. What is mutualism?Ans. Mutualism is a relationship between two kinds of

organismsinwhichbothpartiesgetbenefit. It isafriendly relationship.

Unit Review

Science Words food web habitat omnivores parasitism predator Complete each of the following sentences with

the words given above. 1. The animals that can eat both plants and animals are

called __________.2. In nature, a number of food chains are interconnected

to form a ___________.3. The place where an organism lives is known as its

____________.4. A __________ is an animal that hunts and eats other

animals.5. The master-slave relationship between two different


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organisms is called __________.

Answer: 1. omnivores 2. food web 3. habitat 4. predator 5. parasitism

Multiple Choice Questions Circle the letter of the best answer.1. Different populations living together form a: (a) habitat ` (b) community (c) biosphere (d) ecology2. Organisms that feed on plants directly or

indirectly are called: (a) producers (b) predators (c) prey (d) consumers3. Most organisms are active and happy at

temperatures: (a) between 0°C and 45°C (b) beyond 45°C (c) below 0°C (d) between –10°C and 10°C4. The chameleon eats insects. The relationship is: (a) predator-prey (b) parasitism (c) mutualism (d) symbiosis5. Theseorganismscanfixatmosphericnitrogen: (a) bacteria (b) fungi (c) plants (d) animals

Answer: 1. (b) 2. (d) 3.(a) 4. (a) 5. (a)


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Detailed-Answer QuestionsQ1. How do plants depend upon animals for their

needs?Ans. Plants Depend upon Animals Plants depend upon animals in various ways:

i. For Carbon dioxide: Animals release carbon dioxide during respiration. Plants use it to make food.

ii. For Pollination: Some animals like insects, birds, etc. help plants in their pollination.

iii. For Seed Dispersal: Some animals eat fruit and carry seeds to other places. Some seeds stick to the bodies of animals and disperse.

Q2. Explain the abiotic factors of the environment.Ans. Abiotic Factors of the Environment Abiotic environment means non-living environment.

Light, temperature, soil, air and water are abiotic factors in an environment.i. Light energy is used by plants to make food.

This food is also used by all other living things. The sun is the major source of light on the Earth.

ii. Temperature affects the activities of plants and animals. Most organisms are happy at temperatures between 0°C and 45°C.

iii. Air is used by both plants and animals in respiration. Plants also use carbon dioxide of air to make food.


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iv. Soil helps plants to grow. Many animals also live in soil.

v. Water is essential for life on the Earth. Plants use it to make food. Animals also need water to survive.

Q3. Explain the following with examples: (1) Parasitism (2) Mutualism (3) Types of consumersAns. (1) Parasitism: Parasitism is the master-slave

relationship between two kinds of organisms. The parasite takes food and shelter from the host (slave). It also harms the host. For example, lice in our head are parasites. They suck our blood and harm us.

(2) Mutualism: It is a friendly relationship between two kinds of organisms. Both parties get benefit.For example, termites eat wood but cannot digest it. A protozoan lives in termite’s intestine. It helps the termite to digest wood.

(3) Types of consumers: Consumers are of three types.i. Herbivores: These animals eat only plants. For

example, cow, goat, deer, etc. are herbivores.ii. Carnivores: These animals only eat meat of

other animals. For example, lion, dog, snake, etc. are the carnivores.

iii. Omnivores: These animals eat both plants and meat of other animals. For example, man, monkey, crow, bear, etc. are omnivores.


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Unit 6The Hidden Structure of Matter

Section Review I

Q1. Definemass.Ans. The quantity of matter in an object is called its mass.Q2. Name the personalities which were the first to

describe the hidden structure of matter.Ans.DemocritusandJohnDaltonwerethefirsttodiscuss

the hidden structure of matter.Q3. What is a molecule?Ans. Two or more atoms combine to form a molecule. A

water molecule (H2O) has three atoms, one oxygen and two hydrogen atoms.

Q4. Howwouldyoudefineanelement?Ans. The matter made of only one kind of atoms is called

an elements, e.g. silver, gold, iron,oxygen etc. are elements.

Q5. Write symbols of the following elements: carbon,iron,sodium,oxygen,fluorineAns. Carbon (C), iron (Fe), Sodium (Na), Oxygen (O),

Fluorine (F).Q6. What do you mean by malleability and ductility

of metals?Ans. Malleability The property of metals due to which they can be

beaten into sheets is called malleability. Ductility The property of metals due to which they can be


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drawn into wires is called ductility.Q7. Writebrieflyabouttheusesof: oxygen, hydrogen, iodine, carbonAns. i. Oxygen gas is used in hospitals.

ii. Hydrogen gas is used in welding and fertilizers.iii. Iodine is used to cure goiter.iv. Carbon as diamond is used in jewelry.

Section Review II

Q1. Name the product when two or more elements combine chemically.

Ans. When two or more elements combine chemically, they form a compound.

Q2. Describebrieflythe importanceofwater inourlives.

Ans. Water is a compound. It is made of two gases, i.e. hydrogen and oxygen. It is used in homes, in industries and in agriculture. Living things need water to survive.

Q3. Write a few uses of sodium chloride.Ans.Sodiumchlorideortablesaltisusedtopreservefish

and pickles. It is added to food to make it salty. It is also used in industry to make several compounds.

Q4. Defineamixture.Ans. When two or more substances are combined in such

a way that no chemical change takes place, a mixture is formed.

Q5. Write the composition of hydrogen chloride and carbon dioxide.


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Ans. i. Hydrogen chloride (HCl) is composed of one atom of hydrogen gas and one atom of chlorine gas.

ii. Carbon dioxide (CO2) is composed of one carbon atom and two atoms of oxygen.

Q6. How is ice-cream a mixture?Ans.Ice cream is amixtureofmilk, sugar andflavour.

There is no chemical change takes place.

Section Review III

Q1. Whatisafiltrate?Ans.The substance that passes through a filter paper

duringtheprocessoffiltrationiscalledafiltrate.Q2. Howisairfilteredbeforeenteringyourbody?Ans.Thehair andmucus in our nose helpfilter the air

before entering our lungs.Q3. What is ‘sublimation’? Name four substances

which have the property of sublime.Ans. The process in which a solid on heating, directly

changes into vapour is called sublimation. Following substances can sublime.

i. Ammonium chlorideii. Camphoriii. Iodine crystalsiv. Dry ice (Solid carbon dioxide)

Q4. Define"distillation".Ans. The process of converting a liquid into vapour by

heating and then condensing the vapour into liquid is called distillation.


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Q5. What is the main industrial use of the process of distillation?

Ans. The main industrial use of the process of distillation isintheoilrefinery.Thisprocessisusedtoseparatecomponents of the crude oil or petroleum.

Unit Review

Science Words alloy atom tensile strength symbols salt

substance ratio residue Complete each of the following sentences with the

words given above that will make the sentence correct.

1. The word __________ refers to a particular kind of things.

2. A fixed __________ of elements can form acompound.

3. _________ is the ability of a matter to bear a lot of strain without breaking.

4. The word _________ means indivisible.5. An __________ is a material that contains more

than one metals.6. Sodium chloride is a _________.7. During filtration, the substance which remains on

thefilterpaperiscalled_______.8. Brethelot proposed _______ for elements.

Answer: 1. substance 2. ratio 3. tensile strength 4. atom 5. alloy 6. salt

7. residue 8. symbols


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Multiple Choice Questions Encircle the letter of the best answer.1. Everything which has some mass and occupies

some space is: (a) atom (b) matter (c) element (d) mixture2. What is the percentage of non-metal elements? (a) 30 (b) 40 (c) 60 (d) 703. One metal is found in liquid state: (a) Ag (b) Na (c) Al (d) Hg4. The process shown in the equation solid vapour: (a)filtration (b)sublimation (c) distillation (d) chromatography5. PVC pipes contain: (a) phosphorous (b) chlorine (c) gold (d) mercury6. A new thing formed in a chemical reaction of

elements is called: (a) mixture (b) atom (c) compound (d) reactant7. The word atom has its origin from: (a) Chinese (b) English (c) Roman (d) Greek8. A glucose molecule has ___________ atoms. (a) 20 (b) 24 (c) 12 (d) 6


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9. One is not an element: (a) magnesium (b) phosphorous (c) potassium (d) water10. One is not a mixture: (a) air (b) salad (c) sugar (d) ice-cream

Answer: 1. (b) 2. (a) 3. (d) 4. (b) 5. (b) 6. (c) 7. (d) 8. (b) 9. (d) 10. (c)

Detailed-Answer Questions

Q1. Describe physical properties of metal elements.Ans. Physical Properties of Metals: Metals are widely

used due to their physical properties.i. State: Mostly metals are solids, but mercury is

found in liquid state.ii. Hardness: Mostly metals are hard. They are

used to make rails, bridges and utensils, etc.iii. Luster: Freshly cut metals are shiny. Metals are

used to make frames and ornaments.iv. Melting and boiling points: Metals have high

melting and boiling points. They are used to make kitchen ware.

v. Conductivity: Metals are used to make electrical wires for this property.

Q2. Defineacompound.Giveexamplesanddescribeproperties of compounds.

Ans. Compound: A compound is a new substance formed


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when two or more elements combine chemically in a fixedratio.

Example: carbon (coal) reacts with oxygen gas to form carbon dioxide gas.

Carbon+Oxygen Carbon dioxide

Properties of compoundsi. The properties of compound are different from

the reacting elements.ii. Elements combine in afixed ratio bymass to

form a compound. Example: Hydrogen and oxygen elements combine

in a 1:8 ratio by mass to form water. Hydrogen and oxygen are gases but water is a liquid. Hydrogen+Oxygen WaterQ3. Write about the following methods of separating

mixtures: Sublimation DistillationAns. Sublimation The process in which a solid on heating, directly

changes into vapour is called sublimation. solid heating

cooling vapour We can use this process to separate the two

components of a mixture if one compound has the property of sublime.

Distillation The process of converting a liquid into vapour by

heating and then condensing the vapour into liquid is called distillation.

This process is used to separate miscible liquids


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which have different boiling points. Distillation is also used to separate soluble solids from mixtures.

Q4. Definepaperchromatographyandexplainitwiththe help of an activity.

Ans. Paper Chromatography Chromatography is the separation of coloured

chemicals. Paper chromatography uses paper to separate the different parts present in a mixture.

Activity Separate and identify different components in

dyes. You will need:

(i) a beaker(ii) a medicine dropper(iii) afilterpaper(iv) a solution of a dye or

ink

filterpaper

dye

beaker Procedure Placeafilterpaperonthebeaker. Put a drop of ink or solution of a dye in the middle

ofthefilterpaper. Soon you will see different bands of colour on the

filter paper. Each band shows the presence of adifferent component of the solution.

Each component in the dyes has different ability of spreading on the paper. Some spread faster than the others. This process is called paper chromatography.


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Unit 7Air

Section Review I

Q1. What is air?Ans. Air is a mixture of a number of gases, water vapour,

smoke and dust particles.Q2. What do you know about the layer of atmosphere

in which we live?Ans. We live in troposphere. This layer of air contains

nitrogen, oxygen, water vapour, etc. The temperature of troposphere is suitable for life. It is about 10-16 kilometres thick.

Q3. How is air important for us? (in four lines)Ans. i. We breathe in air (oxygen).

ii. We need air to burn wood, gas or oil.iii. Plants use air to make food.iv. We pump air into footballs and tyres of our

bikes.Q4. What is a wind vane?Ans. A wind vane shows the direction of wind. Wind

vanes help to forecast the weather.

Section Review II

Q1. Describebrieflythecompositionofair.Ans. i. About 78% of air is nitrogen gas.

ii. About 20% of air is oxygen gas.


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iii. About 0.03% is carbon dioxide gas.iv. Less than one percent are rare gases, water

vapour, smoke and dust particles.Q2. Write four uses of nitrogen gas.Ans. i. The presence of nitrogen gas in air slows down

the process of burning.ii. Plants need this gas to grow.iii. In plants and animals, nitrogen is essential to

make proteins.iv. Nitrogen of air is used in the manufacture of

fertilizers.Q3. What is ‘green house effect’?Ans. When percentage of carbon dioxide increases in air,

it absorbs more heat from the sun. It increases the temperature of the area. This behaviour of carbon dioxide is called green house effect.

Q4. What is smog?Ans. The combination of smoke and fog in air is called

smog.Q5. How is ozone layer destroyed?Ans. Harmful gases in air such as sulpher dioxide,

nitrogen dioxide and chlorofluorocarbons destroythe ozone layer.

Section Review III

Q1. Prove that air has weight.Ans. Take two similar balloons. Fill one with air and keep

the other empty. Now hang the balloons, one at each


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end of a stick. Tie a thread in the centre of the stick. Hold the thread and observe the balance. The stick willtiltonthesideofairfilledballoon.Itshowsthatair has weight.

Q2. How is air pressure measured?Ans. A barometer is used to measure the pressure of air.Q3. Who invented the mercury barometer?Ans. Torricelli of Italy invented the mercury barometer in

1643.Q4. Write four uses of air pressure in our daily life.Ans. Air pressure helps in:Ans. i. Pulling of water out of a hand pump.

ii. Pumping air into a tyre.iii. Filling ink in a pen.iv. Sucking of liquid in a dropper.

Unit Review

Science Words rare gases troposphere active air acid rain air pollution Complete each of the following sentences with the words given above that will make the

sentence correct.1. __________ can cause severe respiratory problems.2. Argon, neon and helium are ____________.3. Oxygen is often referred to as __________.4. Sulphur dioxide, nitrogen dioxide and carbon

monoxide when mix with rain water, cause __________.


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5. __________ is the layer of atmosphere closest to the earth.

Answer: 1. air pollution 2. rare gases 3. active air 4. acid rain 5. troposphere

Multiple Choice Questions Encircle the letter of the best answer.1. Thick blanket of air around the earth is: (a) earth cover (b) atmosphere (c) wind (d) earth’s coat2. Urea- a fertilizer, is made with the help of: (a) air (nitrogen) (b) air (oxygen) (c) air (carbon dioxide) (d) air (water vapour)3. Harmful ultraviolet rays of the sun are blocked

by: (a) nitrogen of the air (b) ozone of the air (c) helium of the air (d) clouds4. Rockets use, during their space journeys: (a) liquid oxygen (b) liquid nitrogen (c) liquid hydrogen (d) liquid carbon dioxide

Answer: 1. (b) 2. (a) 3.(b) 4. (a)

Detailed-Answer QuestionsQ1. What is the atmosphere? Describe its layers in

detail.Ans. Atmosphere The thick blanket of air around the Earth is called

the atmosphere.


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Layers of Atmosphere There are four layers of atmosphere, i.e. troposphere,

stratosphere, mesosphere and ionosphere. 1. Troposphere: This layer is closet to the surface of

the Earth. It is about 10-16 kilometres thick. We live in this layer. Troposphere contains nitrogen, oxygen, water vapour and dust particles.

2. Stratosphere: Second layer is called stratosphere. It is about 50 kilometres up from the Earth. Ozone (O3) layer is present in stratosphere.

3. Mesosphere: Above the stratosphere is the third layer mesosphere. It is up to 85 kilometres from the Earth's surface.

4. Ionosphere: It is the outermost layer of atmosphere. This layer extends about 500 kilometres above the Earth and merges into space.

Q2. Write some uses of oxygen in our daily life.Ans. Uses of Oxygen

i. All living things use oxygen for breathing.ii. Wood, gas and oil need oxygen to burn.iii. Oxygen is used in hospitals to keep patients

alive in lungs and heart diseases.iv. Rocketsuseliquidoxygentomakespaceflights.

Q3. Prove the presence of carbon dioxide in air through an activity.

Ans. To prove the presence of carbon dioxide in air You will need: (i) a test tube (ii) clear lime water

(iii) a cork with two holes (iv) two glass tubes bent at right angle (90°)


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Procedurei. Pour some lime water in a clean test tube.ii. Fix the cork on the mouth of the test tube.iii. Pass both the glass tubing through the holes as

showninthefigure.iv. Suck the air from the tube outside the lime water.v. It drops the pressure of air in the test tube.

After sometime, you will see air bubbles in the lime water which turn it milky.

air out air in

test tube

lime water

The reason is that the air from second tube entered and passed through the lime water to make up the loss of pressure of air. The carbon dioxide of air turned the lime water milky. The other gases of the air don't change the lime water.

Q4. Write properties of air.Ans. Properties of Air Following are some properties of air:

i. Air occupies space.ii. Air has weight.iii. Air exerts pressure.

All these properties prove that air is also matter.


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Identify and Label Identify and label the following diagram.Ans.

Ionospher

stratosphere

Troposphere

Mesophere


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Unit 8Solutions, Suspensions and Colloids

Section Review I

Q1. Definesolution.Ans. A mixture of two or more liquids (solute and solvent),

that are evenly mixed, is called a solution.Q2. Explain why can you not wash off grease or paint

stains with water.Ans. Grease or paint are not dissolved in water. That is

why, we cannot wash off stains of grease or paint with water.

Q3. Give two examples of solid in solid solution.Ans. Brass (mixture of zinc and copper) and bronze

(mixture of copper and tin) are examples of solid in solid solution.

Q4. Why do things not sink in the Dead Sea?Ans. The Dead Sea is highly saturated with salts.

These salts become crystals at slight decrease in temperature. Due to this property, things do not sink in the Dead Sea.

Q5. What is a concentrated solution?Ans. The solution in which the quantity of solute is

relatively more is called a concentrated solution.Q6. Defineanunsaturatedsolution.Ans. A solution in which we can dissolve some more

amount of solute is called an unsaturated solution.


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Section Review II

Q1. Defineasuspension.Ans. A mixture in which the solute particles are large

enough and remain suspended in the mixture is called a suspension.

Q2. What is a ‘slurry’?Ans. A suspension which contains a large amount of

insoluble solid solute is called slurry. The runny paste of cement mixed with water is an

example of slurry.Q3. What is a wall paper paste a solution, a suspension

or a colloid?Ans. Wall paper paste is a colloid.Q4. Give few examples of colloids.Ans. Blood, milk, ice-cream, clouds and fog, etc are a few

examples of colloids.Q5. Write few properties of a suspension.Ans. i. Light rays scatter on passing through the

suspension.ii. Particles can be separated by ordinary filter

paper.iii. The particles of solute settle out on standing.

Q6. Categorize the following in solution, suspension and colloid; ice-cream, fruit squashes, lemonade, lassi, blood

Ans. Solution Suspension ColloidLemonade Fruit squashes Ice-cream

Lassi Blood


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Unit Review

Science Wordsdilute solution oxygen brass suspension


1. A __________ is a mixture in which its components are evenly mixed.

2. __________ is a mixture of zinc and copper.3. Some medicines are available in a _____________

form.4. __________ gas dissolves in water and keeps aquatic

animals alive.5. The solution in which the quantity of solute is

relatively less is known as a __________ solution.

Answer: 1. solution 2. brass 3. suspension 4. oxygen 5. dilute

Multiple Choice Questions

Circle the letter of the best answer.1. ‘Ink in water’ is an example of solution: (a) solid in liquid (b) liquid in gas (c) liquid in liquid (d) gas in liquid2. A solution in which water is the solvent is known

as: (a) saturated solution (b) aqueous solution (c) dilute solution (d) concentrated solution


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3. Carbon dioxide dissolves in water to make: (a) lemonade (b) fruit squash (c) soda water (d) lassi4. One is an example of suspension: (a) “snowfall” inside a paper weight (b) blood (c) smoke (d) fog5. Shaving cream and emulsion paint are: (a) suspensions (b) solvents (c) solutes (d) colloids6. The substances in lesser amount in a solution is a: (a) colloid (b) suspension (c) solute (d) solvent7. The amount of solute in grams, dissolved in 100

cm3 of the solvent at a given temperature is called as its:

(a) speed of dissolving (b) solution (c) suspension (d) solubility

Answer: 1. (c) 2. (b) 3. (c) 4. (b) 5. (d) 6. (c) 7. (d)

Detailed-Answer QuestionsQ1. Describe the particle model of solution.Ans. Particle Model of Solution When we dissolve salt in water, the salt 'disappears'

and a solution is formed. The particles of a salt break down into tiny molecules.

These molecules spread among the spaces between water molecules and a solution is formed.


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Ifwefilterthesolution.Therewillbenoresidueonthefilterpaper.

This is a particle model of solution.Q2. Prove that water is a universal solvent.Ans. Water as a Universal Solvent Water is the greatest dissolver in the world. Many

things dissolve in it easily.Ans. i. Sugar, rock salt, milk, alcohol, lemon juice,

vinegar, etc dissolve in water.ii. Our food dissolves in water and then absorbs in

the blood.iii. Plants absorb minerals dissolved in water

through roots.iv. Oxygen and carbon dioxide gases dissolve in

water for animals and plants in water.Q3. What is solubility? How does temperature affect

the solubility?Ans. Solubility The amount of solute in grams dissolved in 100 cm3

of the solvent at a given temperature is called its solubility at that temperature.

The Effect of Temperature on Solubility The solubility of a solute increases with increase

in temperature. For example, 24 grams of copper sulphate dissolve in 100 cm3 of water at 25°C, 60 grams of copper sulphate dissolve in 100 cm3 of water.

Q4. Compare the properties of solutions, colloids and suspensions.


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Ans. Properties of Solutions, Colloids and SuspensionsSolutions Colloids Suspensions

1. Particles of solute do not settle out.

Particles of solute don’t settle.

Particles of solute settle out on standing.

2. Particles pass through ordinaryfilterpaper.

Particles pass through ordinary filterpaper.

Particles can be separated by ordinaryfilterpaper.

3. Light rays do not scatter on passing through the solution.

Light rays scatter on passing through colloids.

Light rays scatter on passing through the suspension.

Q5. Definethefollowing: Solvent Solute Saturated Solution ColloidAns. Solvent The substance in which solute is dissolved is called

solvent. For example, in a solution of salt and water, water is the solvent.

Solute The substance in a solution that is in less amount is

called solute. In the solution of salt and water, salt is the solute.

Saturated Solution A solution in which we can dissolve no more solute

at that temperature is called a saturated solution. Colloid A colloid is made up of two or more substances

that do not dissolve in each other, but particles of


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one substance seem to be spread evenly through the other. For example, ice-cream, milk and blood, etc are colloids.

Identify and Label Identify the solutions, suspensions and colloids.Ans.

Colloid

SuspensionSolution


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Unit 9Introduction to Energy and Its Forms

Section Review I

Q1. Defineenergy.Ans. The ability of a body to do work is called energy.Q2. Name the kind of energy in a body due to its

motion.Ans. The energy in a body due to its motion is called

kinetic energy.Q3. Mention the kind of energy in a stretched rubber

band and a stone lying at some height.Ans. The energy in a stretched rubber band and a stone

lying at some height is potential energy.Q4. Name the factors upon which the amount of

kinetic energy depends?Ans. Kinetic energy depends upon:

i. Mass of the bodyii. Speed of the body

Section Review II

Q1. Describebrieflythetransferofenergy,whenyoulift a toy car to the top of the ramp and let it move.

Ans. When we lift the toy car to the top of the ramp, potential energy is stored in it. When we let it move, potential energy changes into kinetic energy.

Q2. Definethe“lawofconservationofenergy”.Ans. Law of conservation of energy is stated as, "Energy cannot be made nor it can be destroyed, but


54

it can change form one from to another."Q3. How is energy important in our life?Ans. Energy plays very important role in our lives. We use energy in our all activities. Energy runs our machines. Energy lightens our homes. Energy cooks our meals.Q4. Which form of energy is present in wood, gas and

petrol?Ans. Wood, gas and petrol have chemical energy (potential

energy).Section Review III

Q1. What are energy converters?Ans. The devices which change one form of energy into

another, are called energy converters.Q2. Why is going up stairs or climbing a hill always

tiring?Ans. When we go up stairs or climb a hill, we have to

work that stores in the form of potential energy. This work makes us tiring.

Q3. What are the advantages of producing hydro-electric energy?

Ans. i. The water required to produce hydro-electric energy is available free of cost.

ii. Hydal power stations do not add pollution to atmosphere.

Q4. Which are some renewable sources of energy?Ans. Sunlight, wind, tides, gobar gas and water are some

renewable sources of energy.


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Q5. How can we change solar energy into electricity?Ans. We can change solar energy into electricity with the

help of solar panels.

Unit Review

Science Words solarenergy energyflashinglights gobar gas plant tides source Complete each of the following sentences with

the words given above.1. The plant for biogas is also called __________.2. Water is the __________ of hydro-electric energy.3. Energy, coming from the sun is called __________.4. Sea __________ can generate electricity.5. In the sea, the __________ are used to warn the

ships of dangerous rocks.6. __________ is the ability to do work.

Answer: 1. gobar gas plant 2. source 3.solar energy 4.tides 5.flashinglights 6.energy

Multiple Choice Questions Circle the letter of the best answer.1. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energy2. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy


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3. The most cheap fuel in the world is: (a) natural gas (b) coal (c) biogas (d) oil4. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy

Answer: 1. (b) 2. (b) 3. (c) 4. (d)

Detailed-Answer QuestionsQ1. What is the difference between potential and

kinetic energy? Give two examples.Ans. Potential Energy (P.E) The energy that an object has as the result of change

in its position is called potential energy. Examples

i. Energy in a stretched rubber is P.E.ii. Energy in the wound spring of a clock is P.E.iii. Energy in a brick at some height is P.E.

Kinetic Energy (K.E) The energy in a body due to its motion is called

kinetic energy. Examples

i. Energy in a moving car is K.E.ii. Energy in a falling stone is K.E.iii. Energy in wind is K.E.

Q2. Define and explain the law of conservation ofenergy.


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Ans. Law of Conservation of Energy This law states as: "Energy cannot be made nor it can be destroyed. But

energy can change its form." Explanation Consider a pendulum swinging back and forth. When

the ball stops for a moment at the highest point in its swing, it has no kinetic energy. The energy is all potential. At the lowest point, its speed is maximum, it has no potential energy. The energy is all kinetic. The total energy of pendulum is same at the highest point and lowest paint. It just changes it form.

Q3. Describe at least three renewable sources of energy.

Ans. Renewable Sources of Energy Wood, water, wind, animal wastes, sunlight and

tides of seas are some renewable sources of energy. 1. Water Thekineticenergyofflowingwatercanbechanged

into electrical energy. Hydal power stations produce electricity by water.

The water is available free of cost. Hydal power stations do not add pollution to

atmosphere. 2. Wind Energy Wind has kinetic energy too. This energy can be

used to produce electricity. A windmill converts wind energy into electricity.

Wind is available free of cost. Wind does not cause any pollution.


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3. Solar Energy Sunlight can also produce electricity. Solar panels

convert solar energy into electrical energy. Sun light is also available free of cost. Sunlight does not add pollution.Q4. Write a note on ‘energy transfer in an

environment’.Ans. Energy Transfer in Environment Solar energy comes to Earth. Plants use this energy

to make food and stored chemical (potential) energy. Animals eat food from plants. The chemical energy of food changes into other forms of energy during their activities. Finally, energy dissipates in atmosphere.


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Unit 10Putting Energy to Work: Machines

Section Review I

Q1. Howwouldyoudefineamachine?Ans. Anything that makes our work easier and simpler is

called a machine.Q2. What is the principle of a lever?Ans. The principle of lever is: Load × Load arm = Effort × Effort armQ3. How can you determine the mechanical advantage

of the lever?Ans. Mechanical advantage (M.A) = Load

Effort = Load armEffort arm

Q4. Which is the most important invention of the human history?

Ans. Wheel is the most important invention of the human history.

Q5. Definewheelandaxle.Ans. When a large wheel is connected to a circular rod or

axle, it is called wheel and axle. Wheel and axle is a simple machine.

Q6. What was the announcement of Archimedes about the earth and lever?

Ans. He announced, "Give me a lever long and strong and a place for fulcrum to rest the lever, and I will move the earth alone".

Section Review II

Q1. What is a pulley?


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Ans. A pulley is a wheel with a groove in its edge. The pulley turns around an axle. A rope and pulley are used to lift heavy loads.

Q2. How does a movable pulley work?Ans. A movable pulley has a hook to tie the load. This

pulley moves together with the load. The rope is attached to some support.

Q3. How can you make your work easier, while using pulleys?

Ans. We can use pulleys to make our work easier. If a fixed pulley and amovable pulley work together,they make our work easier.

Q4. What is the function of a gear?Ans. A gear is a toothed-wheel. It helps to rotate objects

faster and easily.Q5. How do gears work in a wind-up clock?Ans. In a wind-up clock the minute wheel is a smaller

wheel while the hour wheel is a bigger one. The minute wheel rotates the minute hand faster. The hour wheel rotates the hour hand slowly.

Q6. What is a compound machine?Ans. When two or more simple machines work together,

it is called a compound machine.Unit Review

Science Words load cross-spanner mechanical advantage

effort arm driving wheel Complete each of the following sentences with

the words given above.


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1. A gear on which force is applied is called __________.2. The point at which the lever lifts or moves objects is

called ___________.3. A __________ is a good example of wheel and axle.4. The __________ shows how many times is the load

greater than the effort.5. The distance between the effort and fulcrum is called

_________.

Answer: 1. driving wheel 2. load 3.cross-spanner 4. mechanical advantage 5. effort arm

Multiple Choice Questions Circle the letter of the best answer.1. A nutcracker is an example of a: (a) screw (b) pulley (c) gear (d) lever2. The steering wheel of motor vehicles is an example

of: (a) lever (b) pulley (c) wheel and axle (d) screw3. Which system consists of at least two toothed

wheels? (a) lever system (b) pulley system (c) gear system (d) complex system4. The chain of your bicycle is a: (a) pulley (b) lever (c) screw (d) wheel and axle5. The egg-beater consists of: (a) pulley system (b) screws


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(c) gear system (d) leversAnswer: 1. (d) 2. (c) 3. (c) 4. (a) 5. (c)

Detailed-Answer QuestionsQ1. (a) Describe the principle of a lever. (b) When you apply a force of 300 newton on a

lever to lift a load of 1200 newton. What would be the mechanical advantage (M.A.)

of your lever?Ans. (a) Principle of a lever The lever is balanced when Load × Load arm = Effort × Effort arm This equation is called the principle of a lever. (b) Effort = 300N Load = 1200N M.A = Load

Effort = 1200N300N

M.A = 4Q2. Write some uses of a wheel and axle in your daily

life.Ans. Uses of a Wheel and Axle: There are many use of

wheel and axle in our daily life.i. A screw driver is an example of wheel and axle.

Its broader part is a wheel. The narrow part acts as an axle.

ii. The steering wheel of a vehicle is also a wheel and axle.

iii. A water tap also acts as a wheel and axle.iv. The doorknob is a wheel and axle.


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v. A drill is an example of wheel and axle.Q3. Describe the two kinds of pulleys and their

working.Ans. Kinds of Pulleys: There are two kinds of pulleys: i. Fixed pulley ii. Movable pulley

i. Fixed pulley: In this kind, the pulley isfixedwith some support. The load is tied to one end of the rope. This pulley is used to change the direction of applied force.

ii. Movable pulley: In this kind, the pulley has a hook to tie the load. The rope is tied to some support. This pulley has double mechanical advantagethanafixedpulley.

Q4. Defineagearandwriteitscharacteristics.Ans. Gear: A gear is a toothed-wheel. A gear system

consists of two toothed wheels. One is driving wheel on which force is applied. The other is driven wheel or gear which turns due to the movement of the driving wheel.

Characteristics of Gears:i. Gears transfer energy.ii. Gears can change the direction of applied force.iii. When the driving wheel is larger than the driven

wheel, the gear system is used to increase the speed.

iv. When the driving wheel is smaller the gear system provides great force to overcome resistance.


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Unit 11Behaviour of Light

Section Review I

Q1. What are luminous and non-luminous objects?Ans. The objects which give out their own light are called

luminous objects. The objects that do not give out their own light are

callednon-luminousobjects.TheSun,bulbandfireare luminous while Earth, wall, ball, etc. are non-luminous objects.

Q2. Statethelawsofreflection.Ans.Therearetwolawsofreflection:

i. The angle of incidence is equal to the angle of reflection.

ii. Theincidentray,thereflectedrayandnormalatthe point of incidence all lie on the same plane.

Q3. Whatare theusesof irregularreflection inoureveryday life?

Ans. i. Sunlight reaches our rooms due to irregular reflectionoflight.

ii. We can see things before sunrise and after the sunsetduetotheirregularreflectionoflight.

Q4. Whatistheregularreflectionoflight?Ans.Whenlightstrikesasmoothsurface,itsraysreflect

without changing its pattern. The angles of incidence of all the light rays are equal, so are their angles of reflection.Itiscalledregularreflectionoflight.


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Section Review II

Q1. Defineamirror.Ans. A shiny surface is called a mirror.Q2. Compare the images formed by a plane mirror

and a pin-hole camera.Ans. i. A plane mirror forms a virtual image. A pin-hole

camera forms real images.ii. A plane mirror forms the image of equal size as

of the object. A pin-hole camera forms enlarged or diminished images.

iii. The images formed by a plane mirror are up right. A pin-hole camera forms inverted images.

Q3. Describe three uses of a periscope.Ans. i. Periscopes are used in submarines to see ahead

or over the surface of water.ii. Battle tanks use periscopes to see ahead.

Q4. What do you know about a microscope?Ans. A microscope is a device used to see tiny objects. we

cannot see them with unaided eye.Q5. How can a scientist see the details of the moon?Ans. Scientists use telescopes to see the details of the

moon.Q6. What is a pin-hole camera? Who invented it?Ans. A device which makes use of the fact that light

travels in straight lines is called a pin-hole camera. A Muslim scientist Al-Haithem invented the firstpin-hole camera.


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Section Review III

Q1. How many types of curved mirrors are there?Ans. There are two types of curved mirrors. i.e. convex

mirror and concave mirror.Q2. What is the difference between a virtual and a

real image?Ans. The image which cannot be obtained on a screen is

called a virtual image. The image which can be obtained on a screen is

called a real image.Q3. Write at least four uses of a concave mirror.Ans. i. A dentist's mirror is a concave mirror.

ii. A cosmetic mirror is a concave mirror to make face look bigger.

iii. A search light has a concave mirror to throw light at a distance

iv. Areflectormirrorinamicroscopeisaconcavemirror.

Q4. Define:centerofcurvature,principalaxis.Ans. The centre of the curve whose part is a mirror, is

called the centre of curvature. It is denoted by 'C'. The line joining the centre of curvature 'C' and pole

'P' of the mirror is called the principal axis.Q5. What is the ‘principal focus’ of a concave & a

convex mirror?Ans.Whenlightraysstrikeaconcavemirror,theyreflect

and pass through a common point, called its principal focus.


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Whenlightraysstrikeaconvexmirror,theyreflectand spread. They seem to come from a common point in the mirror called its principal focus.

Q6. Can you obtain a virtual and upright image from a concave mirror? Draw a ray diagram.

Ans. Yes, we can obtain a virtual and upright image from a concave mirror. We have to place the object between 'F' and 'P'.

Virtual Image

F PC

Virtualimage

Unit Review

Science Words shadow,translucent,virtual,pole,infinity Complete each of the following sentences with

the words given above. 1. The center of a curved mirror is called __________.2. The image of the object at __________ forms at the

principal focus ‘F’ of the concave mirror.3. Some material things allow some light to pass

through and scatter the rest in many directions. They are called __________ materials.

4. The image formed by a plane mirror is called a


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__________ image.5. When an opaque object is placed in the path of light,

a __________ is formed.

Answer: 1.pole 2.infinity 3.translucent4. virtual 5. shadow

Multiple Choice Questions Circle the letter of the best answer.1. One is a luminous object: (a) the moon (b) book (c)chair (d)firefly2. One statement is not correct for the plane mirror: (a) the image formed is upright (b) the image is equal in size (c) the image is real (d) the image is laterally inverted3. A mirror curved like the outside of the bowl of a

spoon is called a: (a) convex mirror (b) plane mirror (c) concave mirror (d) concavo-plane mirror4. The distance between pole ‘P’ and principal focus

‘F’ of a concave mirror is called: (a) radius of curvature (b) radius of circle (c) focal length (d) center of curvature5. A concave mirror forms a virtual image when the

object is present: (a) at ‘F’ (b) between ‘F’ and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’


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Answer: 1. (d) 2. (c) 3. (a) 4. (c) 5. (d)

Detailed-Answer QuestionsQ1. Describe the transmission, absorption and

reflectionoflight.Ans. Transmission of Light: When light falls on

transparent objects, it is transmitted or passed to the other side. It is called transmission of light.

Absorption of Light: When white light shines on rough or opaque objects, most part of the light is absorbed and changed into heat to warm the surface.

ReflectionofLight:When light falls on a smooth, shiny surface, it bounces off in one particular direction. This bouncing off of light is called reflectionoflight.

Q2. Provethelawsofreflectionthroughanactivity.Ans. Fix a white paper on a drawing board using the

drawing pins. Place a mirror stripAB (fixed in a stand) on the

paper. Fix two common pins Q and R before the mirror in

a slant line. See the imagesof thesepins in themirror andfix

two more common pins S and T in such a way that images of Q and R and pins S and T lie on the same straight line.

Join the points Q, R, S, and T with the AB on point P. Draw a perpendicular line on P. It is a normal.

Observe the angle of incidence QPN that incident


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ray QR forms with the normal and the angle of reflectionNPTthatreflectedraySTformswiththenormal. You will observe that:

The angle of incidence is equal to the angle of reflection.

Theincidentray,thereflectedrayandthenormalatthe point of incidence all lie on the same plane.

This activity proves thelawsofreflection.

Q3. Draw a ray diagram for light reflected from aplane mirror.

Ans. Raydiagram forLightReflectedFromaPlaneMirror

MA N B

R

I

incidentrays

P

Q S

T

reflected ray

b baa

refle

cted

ray

(first position) (second position)

O

Q4. How does multiple reflection occur in akaleidoscope?

Ans. ReflectioninaKaleidoscope:A Kaleidoscope is

AP

B

Q

R S

T

N


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an optical instrument in which constantly changing patterns of a simple design can be viewed.

Experiment: Draw two mutually perpendicular lines onasheetofwhitepaperfixedonadrawingboard.Draw some design with colour pencils between these lines. Place two mirror strips vertically on these lines. You may use modeling clay to stand the mirror strips. Observe the images of the design in one of the mirrors. The number of images seen is 3.

Now change the angle between the two mirrors, for example 60o. Again observe the images in one of the mirrors. The number of images now seen is 5.

Q5. Describe in detail the image formation in curved mirrors.

Ans. Image Formation in Curved Mirrors A concave mirror can form real as well as virtual

image, but a convex mirror only forms a virtual image. Let us study images of objects at different distances from the curved mirrors.

Image with a convex mirror A convex mirror always produces a virtual, upright

and smaller image of the object at any distance in front of it. The image is located behind the mirror.

P F

object

C

virtual image

Convex mirror


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Images With a Concave Mirror A concave mirror has an original principal focus 'F'.

That is why it can form real images on a screen. (a)ObjectatInfinity If the object is

locatedatinfinity,the image forms at the principal focus 'F' in front of the concave mirror. This image is real and very small. You can make the image of the sun in the form of a dot at paper with the help of a concave mirror. Try it on your hand!

(b) Object Beyond the Center of Curvature If the object is

located beyond the center of curvature 'C', its image forms between 'F' and 'C' in front of the mirror. The image is real, inverted and small in size .

(c) Object at the Center of Curvature If the object is

located at the center of curvature 'C', the image also forms on the center of curvature 'C' in

PFC

Concavemirror

PFC

object

real image

Concave mirror

PFC

object

real image

Concave mirror


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front of the mirror. This image is real, inverted and of the same size as of the object.

(d) Object Between Center of Curvature and Focusus

If the object is placed between 'C' and 'F’, the image forms beyond the center of curvature 'C' in front of the mirror. The image is real, inverted and bigger in size.

(e) Object at Principal Focus If the object is located

at the principal focus ‘F’ of the concave mirror, the rays after reflection from themirror become almost parallel. The image will be formed at infinity.Thisimagecannotbeobtainedonscreen.

(f) Object Between Focus and Pole If the object is placed very near to the concave

mirror that is between principal focus 'F' and pole 'P', the rays after reflectionmove away fromeachother and seem coming from behind the mirror. The image forms behind the concave mirror. It is virtual, upright and bigger in size.

PFC

object

real image

Concave mirror

F

Cobject

Concave mirror

P


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F

C

object

Concave mirror

P

virtualimage

Identify and Label Identify and label the following diagram.Ans. P PoleC Centre of curvatureR Radius of Curvature

P C

R

P

Principal axis

Convex mirrorConcave mirror


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Unit 12Sound Around Us

Section Review I

Q1. What is sound?Ans. Sound is a form of energy. We hear it with our ears.Q2. How are all sounds alike?Ans. All sounds are alike because they produce as a result

of vibration.Q3. How can one produce louder sounds?Ans. When one uses more force to produce vibration, it

cause a loud sound to be produced.Q4. On the surface of the moon, astronauts cannot

converse like on the earth. Why?Ans. Sound needs a medium (solid, liquid or gas) to

travel. On the surface of the moon, There is no air or water. That is why, astronauts cannot converse as they can on the earth.

Section Review II

Q1. What is the speed of sound while passing through water at room temperature?

Ans. The speed of sound in water is 1500 metres per second.

Q2. How does sound move through solids more easily than it moves through air?

Ans. Solid materials have closely packed molecules which helps sound to move faster through them. The particles in air are not packed. So sound travels


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easily through solids than air.Q3. What happens when sound waves reach the

eardrum?Ans. When sound reaches our eardrum, it causes

vibration. This vibration is sent to the next parts of the ear.

Q4. How can sounds be harmful?Ans. Loud sound for longer periods can cause headache,

nausea and sleeplessness . It can also damage your hearing permanently.

Q5. What are vocal cords?Ans.Vocalcordsarethinflapsinourthroatthatproduce

sound.

Unit Review

Science Words vibrate, volume, vocal cords, telephone, voice Complete each of the following sentences with

the words given above. 1. Loud __________ is an unpleasant sound.2. You can talk to your friend at a long distance via

__________.3. The more an object vibrates, the louder the

__________ will be.4. The air particles next to bell begin to _________

when the bell rings.5. When you talk, air comes from the lungs and passes

between the ____________.


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Answer: 1. voice 2. telephone 3.volume 4. vibrate 5. vocal cords

Multiple Choice Questions Circle the letter of the best answer.1. Sound waves travel most quickly through: (a) solids (b) gases (c) air (d) liquids2. Noise is a health hazard because it causes: (a) hearing loss (b) soothing effect (c) low blood pressure (d) nervous relaxation3. The sound waves cannot pass through: (a) steel (b) wood (c) glass (d) vacuum4. The speed of sound in steel is: (a) 330 meters per second (b) 2,100 meters per second (c) 1,500 meters per second (d) 6,000 meters per second

Answer: 1. (a) 2. (a) 3. (d) 4. (d)

Detailed-Answer QuestionsQ1. Prove that sound is a form of energy.Ans. Sound as a form of Energy We know that energy is the ability to do work. Energy

can move things. Sound can also move things. When we hit a drum, its surface vibrates. These vibrations move through air and reach our eardrums. Here they


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cause our eardrums to vibrate and we hear sound. As sound vibrates things, so it is a form of energy.

Q2. How does sound travel?Ans. Sound Travels Sound needs a medium to travel from one place

to the other. The medium may be gas (air), liquid (water) or solid (metal).

When some object produces sound, the particles of the medium bump into each other and carry vibrations of sound to other place. Sound sannot travel through a vacuum due to the absence of any particles.

Q3. How do you produce sound?Ans. Making Sound We know that sound is produced by the vibrations.

In our throat, vocal cords are present. When we talk, air comes from our lungs and pushes between our vocal cords. This makes our vocal cords to vibrate. The vibrating movement of our vocal cords makes sound. We can experience it while placing our fingersonthethroatofhuman.


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Unit 13Exploring Space

Section Review I

Q1. Where is the asteroid belt found?Ans. The asteroid belt is found between Mars and Jupiter.Q2. Who is an astronomer?Ans. A scientist who studies the stars, planets and other

objects in space is called an astronomer.Q3. What are comets’ tails made of?Ans. The tail of comets is made up of gases and dust

particles.Q4. What happens to most meteors?Ans. Most meteors which enter our atmosphere, burn up

50 to 100 kilometres above the surface of the earth.Q5. What do you know about Barringer Crater?Ans. The barringer crater is a huge crater made by a

meteorite in Arizona (America). It is 1,200 metres wide and 180 metres deep.

Q6. When can comets be seen?Ans. Comets are seen only when they come close to the

sun.Section Review II

Q1. Whatareartificialsatellites?Ans. The man-made satellites orbiting the earth are called

artificialsatellites.Q2. What is the function of a satellite moving in the

polar orbit?


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Ans. The satellites moving in the polar orbit are used for mapping and weather forecasting. These satellites scan the whole earth during their motion.

Q3. How do satellites tell us where we are?Ans. Locating the position of objects with the help of

a satellite is called the Global Position System or GPS. This satellite can tell our position on the earth.

Q4. How are satellites sent into space?Ans. A satellite is mounted on the top of a very high speed

rocket to sent it into space.Q5. What is a satellite receiving station?Ans. A station on the Earth that receives messages from

satellites is called a satellite receiving station.Q6. Writefiveusesofartificialsatellites.Ans. UsesofArtificialSatellites Theartificialsatellitesareusedfor:

i. communicationsii. mapping of the earthiii. weather forecastingiv. locating mineral resources in the earth

locating our position anywhere in the world

Unit Review

Science Words orbit comet asteroids communication Complete each of the following sentences with

the words given above. 1. Two __________ are seen from the earth without

the help of a telescope.


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2. The path a planet follows around the sun is its __________.

3. __________ satellites move in geostationary orbit.4. A space object made of ice and dust particles is a

__________.

Answer: 1. asteroids 2. orbit 3.communication 4. comet

Multiple Choice Questions Circle the letter of the best answer.1. The Comet Halley appears after: (a) 50 years (b) 35 years (c) 60 years (d) 76 years2. Thefirstartificialsatellitewassentintospacein: (a) 1957 (b) 1939 (c) 1969 (d) 19523. Thefirstmaninspacewas: (a) Edwin Aldrin (b) Neil Armstrong (c) Dr. Sally Ride (d) Yuri Gagarin4. Locating the position of objects with the help of a

satellite is called: (a) GRS (b) GMS (c) GPS (d) PGS

Answer: 1. (d) 2. (a) 3. (d) 4. (c)

Detailed-Answer QuestionsQ1. Write a detailed note on comets.Ans. Comets: Comets are the part of our solar system.


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They orbit the sun in eliptical paths. A comet is a heavenly body made of ice and dust particles. Comets are only seen when they come close to the sun.

Parts of a Comet A comet has three parts, a head, coma and a tail.

The head is made of ice, particles of rock and gases. A large, fuzzy, circular cloud around the head of a comet is called coma.

During orbiting near the sun, a long tail of gases and dust particles is formed behind the comet. This tail can be millions of kilometres long.

A comet named Comet Halley has appeared in the sky several times.

Q2. Describetheorbitsofartificialsatellites.Ans. OrbitsofArtificialSatellites Artificialsatellitesmovearoundthesunindifferent

orbits depending upon the purpose of the satellite. 1. Geostationary Orbit In a geostationary orbit, a satellite completes one

round in 24 hours. The satellite looks stationary in this orbit. Communication satellites move in geostationary orbit.

2. Polar Orbit Polar orbit passes over the north and south poles of

Earth. Satellites moving in this orbit are used for mapping and weather forecasting.

3. Eccentric Orbit Thescientificsatellitesmoveinthisorbittomeasure

theelectricandmagneticfieldsofearth.


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4. Low Earth Orbit This orbit is very close to the earth. Space stations,

space shuttles and The Hubble Telescope move in low earth orbit. The satellite in this orbit can orbit the earth every 90 minutes.

Q3. What are the key milestones in space technology?Ans. Some Key Milestones in Space Technology Inventions of telescopes and rocket laid foundation

to explore the space. Using these technologies man has achieved great success.

i. In1957,Russiasentfirstsatellitesputnik-1 inspace.

ii. RussiasentYuriGagarin,thefirstmaninspace.iii. In 1969, America sent Apollo-11 on Moon.

NeilArmstrongwasthefirstmantosteponthemoon.

iv. Scientists sent the Hubble Space Telescope in space to get clear images of space objects.


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Model Paper No-11st Term (Units 1-5)

Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. Calculatedtheradiusoftheearthforthefirst

time: (a) Al-Bairuni (b) Dr. Abdus-salam (c) Al-Haitham (d) Galileo2. Science is bad due to this reason. (a) improve health (b) explore space (c) make bombs and war heads (d) increase crops3. By making conclusions you decide weather your: (a) hypothesis is correct (b) experiment is correct (c) problem statement is correct (d) data is correct4. The question you want to answer is your: (a) hypothesis (b) experiment (c) problem (d) conclusion5. Sulphuric acid, nitric acid and hydrochloric acid

were prepared by: (a) Ibn-Al-Haitham (b) Al-Bairuni (c) Jabar Bin Hayan (d) Galileo6. Wastes of the body are removed through: (a) circulatory system (b) excretory system (c) digestive system (d) nervous system


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7. All living material in a cell is called the: (a) nucleoplasma (b) cell rap (c) protoplasm (d) cell’s solution8. The food making structures in green plant cells

are the: (a) vacuoles (b) mitochondria (c) Golgi bodies (d) chloroplasts9. Heart, liver and ears are examples of animal: (a) organs (b) tissues (c) cells (d) organ systems10. The power houses of the cell are: (a) chloroplasts (b) mitochondria (c) Golgi bodies (d) chloroplasts11. Different populations living together form: (a) habitat (b) community (c) biosphere (d) ecology12. Theseorganismscanfixatmosphericnitrogen: (a) bacteria (b) fungi (c) plants (d) animals13. The chameleon eats insects. The relationship is: (a) predator-prey (b) parasitism (c) mutualism (d) symbiosis14. Most organisms are active and happy at

temperatures: (a) between 0°C and 45°C (b) beyond 45°C (c) blow 0°C (d) between -10°C and 10°C


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15. Organisms that feed on plants directly or indirectly are called:

(a) producers (b) predators (c) prey (d) consumers16. All animals and plants respire in: (a) carbon dioxide (b) oxygen (c) nitrogen (d) hydrogen17. During the respiration organisms release a gas: (a) oxygen (b) nitrogen (c) carbon dioxide (d) 18. Glucose prepared by plants is converted into: (a) protein (b) fat (c) starch (d) salts19. The level of carbon dioxide in air is about: (a) 0.03 % (b) 21% (c) 78% (d) 1.5 %20. Chlorophyll does not absorb this colour of light: (a) blue (b) yellow (c) orange (d) redPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (omnivores, respiration, multicellular, anvil, medical science)(i) During _______, energy is produced by using glucose and oxygen.(ii) The animals that can eat both plants and animals are called _______.(iii) Second bone of the middle ear is _______.(iv) A _______ organism consists of several cells.(v) Scientificresearchesin_______haveimproved human health.


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• Answerthefollowingquestions. (10×5)22. (a) Give arguments to prove that science is good

not bad. (7) (b) Who is the father of chemistry? (3)23. (a) How does an amoeba move? And what is a cell? (3) (b) Write a note on amoeba. (7)24. (a) Describe the structure of human eye. (7) (b) How do your tongue feel different tastes? (3)25. (a) Describe the internal structure of a leaf. (7) (b) Which surface of leaf contains more stomata? (3)26. (a) How does light affect lives of plants and animals in an environment? (3) (b) How do plants depend upon animals for their needs? (7)


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. stomata are found abundantly in: (a) lower epidermis of a leaf (b) upper epidermis of a leaf. (c) stem (d) roots2. xylem vessels conduct: (a) food (b) water (c) sunlight (d) chlorophyll3. photosynthesis is a combination of two: (a) English words (b) Latin words (c) Arabic words (d) Greek words.4. Exchange of gases takes place through: (a) stomata of leaf (b) xylem vessels (c) phloem cells (d) mesophyll tissues5. Products of photosynthesis are: (a) carbon dioxide and water (b) hydrogen and water (c) glucose and carbon dioxide (d) glucose and oxygen6. Chlorophyll does not absorb this colour of light: (a) blue (b) yellow (c) orange (d) red7. The control room of your body is: (a) heart (b) stomach (c) brain (d) liver


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8. Which sense organ tells you about pressure? (a) ear (b) tongue (c) nose (d) skin9. The sides of your tongue are sensitive for: (a) salty and sour tastes (b) sour and sweet taste (c) sweet taste (d) bitter taste10. Which cells of retina in your eyes are stimulated

in bright light? (a) cone cells (b) rod cells (c)roundcells (d)flatcells11. When nerves are damaged or pressed hard you

feel: (a) cold (b) hot (c) pain (d) strange12. The liquid present between the lens and retina of

your eye is: (a) vitreous humor (b) aqueous humor (c) water (d) salt solution13. All living material in a cell is called the: (a) nucleoplasm (b) cell sap (c) protoplasm (d) cell’s solution14. The food making structures in green plant cells

are the: (a) vacuoles (b) mitochondria (c) Golgi bodies (d) chloroplasts15. The power houses of the cell are: (a) chloroplates (b) mitochondria (c) Golgi bodies (d) chromosomes


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16. Sulphuric acid, nitric acid and hydrochloric acid were prepared by:

(a) Ibn-Al-Haitham (b) Al-Bairuni (c) Jabar Bin Hayan (d) Bu Ali Sina17. Calculated the radius of the earth for the first

time: (a) Al-Bairuni (b) Dr. Abdus-salam (c) Al-Haitham (d) Galileo18. By making conclusions, you decide weather your: (a) hypothesis is correct (b) experiment is correct (c) problem statement is correct (d) data is correct19. The question you want to answer is your: (a) hypothesis (b) experiment (c) problem (d) conclusion20. Science is bad due to this reason: (a) improve health (b) explore space (c) make bomb and war heads (d) increase crop’s production.Part -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (nucleus, scientist, taste buds, respiration, predator)(i) A person who adopts studying science as a career is called a _______.(ii) _______ is the brain of the cell which controls its functions.(iii) About 8000 _______ are scattered on your tongue.(iv) Plants use water and carbon dioxide to make food in the process of _______.


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(v) A _______ is an animal that hunts and eats other animals.• Answerthefollowingquestions. (5×10)22. (a) How do plants depend upon animals for their needs? (7) (b) What is a prey? (3)23. (a) Which factors are necessary for photosynthesis? (7) (b) which gas is used during respiration? (3)24. (a) Describe the structure of human eye. (7) (b) How do your tongue feel different tastes? (3)25. (a) Write in detail about shoot system of plant. (7) (b) Which system conducts messages in your body? (3)26. (a) Writebrieflythepartsandfunctionsof: (7) (i) Nervous system (ii) circulatory system (b) Why is chlamydomonas considered a plant? (3)


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. Wastes of the body are removed through: (a) circulatory system (b) excretory system (c) digestive system (d) nervous system2. Heart, liver and ears are examples of animal: (a) organs (b) tissues (c) cells (d) organ systems3. When nerves are damaged or pressed hard, you

feel: (a) cold (b) hot (c) pain (d) strange4. The liquid present between the lens and retina of

your eye is: (a) vitreous humor (b) aqueous humor (c) water (d) salt solution5. Which cells of retina in your eyes are stimulated

in bright light? (a) cone cells (b) rod cells (c)roundcells (d)flatcells6. The control room of your body is: (a) heart (b) stomach (c) brain (d) liver7. Which sense organ tells you about pressure? (a) ear (b) tongue (c) nose (d) skin


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8. The sides of your tongue are sensitive for: (a) salty and sour tastes (b) sour and sweet tastes (c) sweet taste (d) bitter taste9. stomata are found abundantly in: (a) lower epidermis of a leaf (b) upper epidermis of a leaf (c) stem (d) roots10. Xylem vessels conduct: (a) food (b) water (c) sunlight (d) chlorophyll11. All animals and plants respire in: (a) carbon dioxide (b) oxygen (c) nitrogen (d) hydrogen12. Photosynthesis is a combination of two: (a) English words (b) Latin words (c) Arabic words (d) Greek words13. Exchange of gases takes place through: (a) stomata of leaf (b) xylem vessels (c) phloem cells (d) mesophyll tissues14. During respiration organisms release a gas: (a) oxygen (b) nitrogen (c) carbon dioxide (d) carbon monoxide15. Products of photosynthesis are: (a) carbon dioxide and water (b) hydrogen and water (c) glucose and carbon dioxide (d) glucose and oxygen


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16. Glucose prepared by plants is converted into: (a) protein (b) fat (c) starch (d) salts17. The level of carbon dioxide in air is about: (a) 0.03% (b) 21% (c) 78% (d) 1.5 %18. Chlorophyll does not absorb this colour of light: (a) blue (b) yellow (c) orange (d) red19. Theseorganismscanfixatmosphericnitrogen: (a) bacteria (b) fungi (c) plants (d) animals20. Organisms that feed on plants directly or

indirectly are called: (a) producers (b) predators (c) prey (d) consumersPart -B (Open Ended Questions) Marks: 7021. Fill in the blanks using following words. (2x5) (chlorophyll, habitat, an organ system, auditory nerve, equipment)(i) The place where an organisms lives is known as ___.(ii) The green pigment in plants is called _______.(iii) _______ carries signals from ear to brain.(iv) A group of different organs working together to perform certain function is called _______.(v) you will use different pieces of _______ in the science laboratory.• Answerthefollowingquestions. (5×10)22. (a) Which safety rules should be followed while working in a Science laboratory? (7)


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(b) How does a scientist test his/her hypothes? (3)23. (a) Who discovered the cell? (3) (b) Describe the structure of a plant cell. (7)24. (a) How is balance of your body maintained? (7) (b) Describe the structure and function of inner ear. (3)25. (a) What functions does epidermis perform in the leaf? (3) (b) Prove that the structure of a leaf facilitates the process of photosynthesis. (7)26. (a) Why are plants called producers? (3) (b) Explain the fallowing with examples: (7) (i) Parasitism’s (ii) Mutualism (iii) Types of consumers


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. The chameleon eats insects. The relationship is: (a) predator-pre (b) parasitism (c) plants (d) animals2. Most organisms are active and happy at

temperatures: (a) between 0°c and 45°c (b) beyond 45°c (c) below 0°c (d) between -10°c and 10°c3. Different populations living together forma: (a) habitat (b) community (c) biosphere (d) ecology4. The power houses of the cell are: (a) chloroplasts (b) mitochondria (c) Golgi bodies (d) chromosomes5. The food making structures in green plant cells

are the: (a) vacuoles (b) mitochondria (c) Golgi bodies (d) chloroplasts6. All living material in a cell is called the: (a) nucleoplasm (b) cell sap (c) protoplasm (d) cell’s solution7. Caculated the radius of the earth for the first

time: (a) Al-Bairuni (b) Dr. Abdus-salam


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(c) Al-Haitham (d) Galileo8. Sulphuric acid, nitric acid and hydrochloric acid

were prepared by: (a) Ibn-Al-Haitham (b) Al-Bairuni (c) Jabar Bin Hayan (d) Bu Ali Sina9. By making conclusions, you decide wether your: (a) hypothesis is correct (b) experiment is correct (c) problem statement is correct (d) data is correct.10. The question you want to answer is your: (a) hypothesis (b) experiment (c) problem (d) conclusion11. Science is bad, due to this reason: (a) improve health (b) explore space (c) make bombs and war heads (d) increase crops production12. Wastes of the body are removed through: (a) circulatory system (b) excretory system (c) digestive system (d) nervous system13. Heart, liver and ears are examples of animal: (a) organs (b) tissues (c) cells (d) chromosomes14. Theseorganismscanfixatmosphericnitrogen (a) bacteria (b) fungi (c) plants (d) animals15. Organisms that food on plants directly or

indirectly are called: (a) producers (b) predators (c) prey (d) consumers


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16. Different populations living together form a: (a) habitat (b) community (c) biosphere (d) ecology17. All animals and plants respire in: (a) carbon dioxide (b) oxygen (c) nitrogen (d) hydrogen18. During respiration organisms release a gas: (a) oxygen (b) nitrogen (c) carbon monoxide (d) carbon dioxide19. Glucose prepared by plants is converted into (a) protein (b) fat (c) starch (d) salts20. Chlorophyll does not absorb this colour of light: (a) blue (b) yellow (c) orange (d) redPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (chlorophyll, food web, unicellular, body balance, equipment)(i) In nature, a number of food chains are interconnected to form a __________(ii) The green pigment in plants is called __________.(iii) Three semi circular canals of inner ear help to maintain your __________.(iv) A one-celled organism is called __________.(v) You will use different pieces of __________ in the science laboratory.• Answerthefollowingquestions. (5×10)22. (a) Brieflydescribethecontributionsoffollowing scientists: (7) (i) Jabir Bin Hayan (ii) Al-Haitham


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(b) Who invented the telescope? (3)23. (a) Describe parts and functioning of a compound microscope. (7) (b) What are the functions of root system in a plant? (3)24. (a) Write a note on the sense of smell. (7) (b) Why does your sense of smell become poor, when you smell a certain odor for quite a long time? (3)25. (a) How does respiration occur in plants? (7) (b) Why do plants release carbon dioxide during night time and not during the day time? (3)26. (a) Explain the abiotic factors of the environment. (7) (b) Write three needs of animals for which they depend upon plants? (3)


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Model Paper No-12nd Term (Units 6-9)

Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. Everything which has some mass and occupies

some space is: (a) atom (b) matter (c) element (d) mixture2. One metal is found in liquid state: (a) Ag (b) Na (c) Al (d) Hg3. The process shown in the equation solid vapour (a)filtration (b)sublimation (c) distillation (d) chromatography4. PVC pipes contain: (a) phosphorous (b) chlorine (c) gold (d) mercury5. The word atom has its origin from: (a) Chinese (b) English (c) Roman (d) Greek6. Thick blanket of air around the earth is: (a) earth cover (b) atmosphere (c) wind (d) earth’s coat7. Urea- a fertilizer, is made with the help of: (a) air (nitrogen) (b) air (oxygen) (c) air (carbon dioxide) (d) air (water vapour)


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8. Harmful ultraviolet rays of the sun are blocked by:

(a) nitrogen of the air (b) ozone of the air (c) helium of the air (d) clouds9. Rockets use, during their space journeys: (a) liquid oxygen (b) liquid nitrogen (c) liquid hydrogen (d) liquid carbon dioxide10. Percentage of CO2 in air is about: (a) 0.01% (b) 0.02% (c) 0.03% (d) 0.04%11. ‘Ink in water’ is an example of solution: (a) solid in liquid (b) liquid in gas (c) liquid in liquid (d) gas in liquid12. Carbon dioxide dissolves in water to make: (a) lemonade (b) fruit squash (c) soda water (d) lassi13. Shaving cream and emulsion paint are: (a) suspensions (b) solvents (c) solutes (d) colloids14. The substances in lesser amount in a solution is a: (a) colloid (b) suspension (c) solute (d) solvent15. The amount of solute in grams, dissolved in 100




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16. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energy17. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy18. The most cheap fuel in the world is: (a) natural gas (b) coal (c) bio gas (d) oil19. Plants use solar energy falling on them: (a) 1/10th (b) less than 1/100th (c) 1/1000th (d) less than 1/10th20. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energyPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (airpollution,tenoilstrength,symbols,flashing lights, oxygen)(i) ________ is the ability of a matter to bear a lot of strain without breaking.(ii) The word ________ means indivisible.(iii) ________ can cause severe respiratory problems.(iv) ________ gas dissolves in water and keeps aquatic animals alive.(v) In the sea, the ________ are used to warn the ships of dangerous rocks.• Answerthefollowingquestions. (5×10)22. (a) Defineandexplainthelawofconservationof energy. (7)


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(b) Which are some renewable sources of energy? (3)23. (a) Write few properties of a suspension. (3) (b) What is solubility? How does temperature affect the solubility? (7)24. (a) How is air pressure measured? (3) (b) Write properties of air: (7)25. (a) write four uses of air pressure in our daily life. (3) (b) What is the atmosphere? Describe its layers in detail. (7)26. (a) Howisairfilteredbeforeenteringyourbody? (3) (b) Describe physical properties of metal elements. (7)


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. What is the percentage of non-metal elements? (a) 30 (b) 40 (c) 60 (d) 702. The process shown in the equation solid vapour: (a)filtration (b)sublimation (c) distillation (d) chromatography3. A new thing formed in a chemical reaction of

elements is called: (a) mixture (b) atom (c) compound (d) reactant4. A glucose molecule has __________ atoms. (a) 20 (b) 24 (c) 12 (d) 65. One is not an element: (a) magnesium (b) phosphorous (c) potassium (d) water6. Percentage of CO2 in air is about: (a) 0.01 % (b) 0.02% (c) 0.03% (d) 0.04%7. Rockets use, during their space journeys: (a) liquid oxygen (b) liquid nitrogen (c) liquid hydrogen (d) liquid carbon dioxide8. Harmful ultraviolet rays of the sun are blocked

by: (a) nitrogen of the air (b) ozone of the air


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(c) helium of the air (d) clouds9. Urea-a fertilizer, is made with the help of: (a) air (nitrogen) (b) air (oxygen) (c) air (carbon dioxide) (d) air (water vapour)10. Thick blanket of air around the earth is: (a) earth cover (b) atmosphere (c) wind (d) earth’s coat11. A solution in which water is the solvent is known

as: (a) saturated solution (b) aqueous solution (c) dilute solution (d) concentrated solution12. One is an example of suspension: (a) “snowfall” inside a paper weight (b) blood (c) smoke (d) fog13. Shaving cream and emulsion paint are: (a) suspensions (b) solvents (c) solutes (d) colloids14. The substances in lesser amount in a solution is a: (a) colloid (b) suspension (c) solute (d) solvent15. The amount of solute in grams, dissolved in

10 cm3 of the solvent at a given temperature is called as its:



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16. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy17. Plants use solar energy falling on them: (a) 1/10th (b) less than 1/100th (c) 1/1000th (d) less than 1/10th18. The most cheap fuel in the world is: (a) natural gas (b) coal (c) bio gas (d) oil19. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy20. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energyPart -B (Open Ended Questions) Marks: 7021. Fill in the blanks using following words. (2×5) (alloy, acid rain, brass, energy, solar energy)(i) Energy, coming from the sun is called ________.(ii) The plant for biogas is also called ________.(iii) ________ is a mixture of zinc and copper.(iv) Sulphur dioxide, nitrogen dioxide and carbon monoxide when mix with rain water, cause______.(v) An ________ is a material that contains more than one metals.• Answerthefollowingquestions. (5×10)22. (a) Defineamixture. (3) (b) Write about the following methods of separating mixtures: (7) sublimation distillation


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23. (a) What is ‘green house effect’? (3) (b) Prove the presence of carbon dioxide in air through an activity. (7)24. (a) Definesolution (3) (b) Describe the particle model of solution (7)25. (a) Why do things not sink in The Dead Sea? (3) (b) Compare the properties of solutions, colloids and suspensions. (7)26. (a) What are energy converters? (3) (b) Write a note on ‘energy transfer in an environment’. (7)


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some space is: (a) atom (b) matter (c) element (d) mixture2. One metal is found in liquid state: (a) Ag (b) Na (c) Al (d) Hg3. The process shown in the equation solid vapour: (a)filtration (b)sublimation (c) distillation (d) chromatography4. PVC pipes contain: (a) phosphorous (b) chlorine (c) gold (d) mercury5. One is not a mixture: (a) air (b) salad (c) sugar (d) ice-cream6. Urea-a fertilizer, is made with the help of: (a) air (nitrogen) (b) air (oxygen) (c) air (carbon dioxide) (d) air (water vapor)7. Harmful ultraviolet rays of the sun are blocked

by: (a) nitrogen of the air (b) ozone of the air (c) helium of the air (d) clouds


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8. Thick blanket of air around the earth is: (a) earth cover (b) atmosphere (c) wind (d) earth’s coat9. Percentage of CO2 in air is about: (a) 0.01% (b) 0.02% (c) 0.03% (d) 0.04%10. Rockets use, during their space journeys: (a) liquid oxygen (b) liquid nitrogen (c) liquid hydrogen (d) liquid carbon dioxide11. ‘Ink in water’ is an example of solution: (a) solid in liquid (b) liquid in gas (c) liquid in liquid (d) gas in liquid12. Carbon dioxide dissolves in water to make: (a) lemonade (b) fruit squash (c) soda water (d) lassi13. Shaving cream and emulsion paint are: (a) suspensions (b) solvents (c) solutes (d) colloids14. The substances in lesser amount in a solution is a: (a) colloid (b) suspension (c) solute (d) solvent15. The amount of solute in grams, dissolved in 100


(a) speed of dissolving (b) solution (c) suspension (d) solubility16. The most cheap fuel in the world is: (a) natural gas (b) coal (c) biogas (d) oil


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17. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy18. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy19. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energy20. Plants use solar energy falling on them: (a) 1/10th (b) less than 1/100th (c) 1/100th (d) less than 1/10thPart -B (Open Ended Questions) Marks: 7021. Fill in the blanks using following words. (2×5) (dilute, energy, troposphere, rare gases, substance)(i) Water is the __________ of hydro-electric energy.(ii) The solution in which the quantity of solute is relatively less is known as a __________ solution.(iii) Argon, neon and helium are __________.(iv) __________ is the layer of atmosphere closest to the earth.(v) The word __________ refers to a particular kind of things.• Answerthefollowingquestions. (5×10)22. (a) What is the main industrial use of the process of distillation? (3) (b) Describe physical properties of metal elements. (7)23. (a) Whatisfiltrate? (3) (b) Definepaperchromatographyandexplainit


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with the help of an activity. (7)24. (a) What do you know about the layer of atmosphere in which we live? (3) (b) Prove the presence of carbon dioxide in air through an activity. (7)25. (a) What is a ‘slurry’? (3) (b) Prove that water is a universal solvent. (7)26. (a) Name the factors upon which the amount of kinetic energy depends? (3) (b) What is the difference between potential and kinetic energy? Give two examples. (7)


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energy2. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy3. The most cheap fuel in the world is: (a) natural gas (b) coal (c) bio gas (d) oil4. Plants use solar energy falling on them: (a) 1/10th (b) less than 1/100th (c) 1/1000th (d) less than 1/10th5. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy6. ‘Ink in water’ is an example of solution: (a) solid in liquid (b) liquid in gas (c) liquid in liquid (d) gas in liquid7. A solution in which water is the solvent is known

as: (a) saturated solution (b) aqueous solution (c) dilute solution (d) concentrated solution8. Carbon dioxide dissolves in water to make: (a) lemonade (b) fruit squash (c) soda water (d) lassi


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9. One is an example of suspension: (a) “snowfall” inside a paper weight (b) blood (c) smoke (d) fog10. Shaving cream and emulsion paint are: (a) suspensions (b) solvents (c) solutes (d) colloids11. Harmful ultraviolet rays of the sun are blocked

by: (a) nitrogen of the air (b) ozone of the air (c) helium of the air (d) clouds12. Rockets use, during their space journeys: (a) liquid oxygen (b) liquid nitrogen (c) liquid hydrogen (d) liquid carbon dioxide13. Percentage of CO2 in air is about: (a) 0.01% (b) 0.02% (c) 0.03% (d) 0.04%14. Thick blanket of air around the earth is: (a) earth cover (b) atmosphere (c) wind (d) earth’s coat15. Urea- a fertilizer, is made with the help of: (a) air (nitrogen) (b) air (oxygen) (c) air (carbon dioxide) (d) air (water vapour)16. One is not an element: (a) magnesium (b) phosphorous (c) potassium (d) water


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17. A glucose molecule has __________ atoms. (a) 20 (b) 24 (c) 12 (d) 618. The word atom has its origin from: (a) Chinese (b) English (c) Roman (d) Greek19. A new thing formed in a chemical reaction of

elements is called: (a) mixture (b) atom (c) compound (d) reactant20. PVC pipes contain: (a) phosphorous (b) chlorine (c) gold (d) mercuryPart -B (Open Ended Questions) Marks: 7021. Fill in the blanks using following words. (2×5) (wind energy, dilute, active, residue, substance)(i) The word __________ refers to a particular kind of things.(ii) Duringfiltration,thesubstancewhichremainson thefilterpaperiscalled________.(iii) Oxygen is often referred to as ________.(iv) The solution in which the quantity of solute is relatively less is known as a __________ solution.(v) ________ is the ability to do work.• Answerthefollowingquestions. (5×10)22. (a) Write the composition of hydrogen chloride and carbon dioxide. (3) (b) Defineacompound.Giveexamplesand describe properties of compounds. (7)23. (a) What is ‘green house effect’? (3)


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(b) Write some uses of oxygen in our daily life. (7)24. (a) Give few examples of colloids. (3) (b) What is solubility? How does temperature affect the solubility? (7)25. (a) Defineasuspension. (3) (b) Definethefollowing: (7) solvent solute saturated solution colloid26. (a) How is energy important in our life? (3) (b) Describe at least three renewable sources of energy. (7)


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Model Paper No-13rd Term (Units 10-13)

Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. Which system consists of at least two toothed

wheels? (a) lever system (b) pulley system (c) gear system (d) complex system2. The egg-beater consists of: (a) pulley system (b) screws (c) gear system (d) levers3. The chain of your bicycle is a: (a) pulley (b) lever (c) screw (d) wheel and axle4. The steering wheel of motor vehicles is an example

of: (a) lever (b) pulley (c) wheel and axle (d) screw5. A nutcracker is an example of a: (a) screw (b) pulley (c) gear (d) lever6. The most cheap fuel in the world is: (a) natural gas (b) coal (c) bio gas (d) oil7. A Stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy


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8. A concave mirror forms a virtual image when the object is present:

(a) at ‘F’ (b) between ‘F; and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’9. The distance between pole ‘P’ and principal focus

‘F’ of a concave mirror is called: (a) radius off curvature (b) radius of circle (c) focal length (d) center of curvature10. A mirror curved like the outside of the bowl of a

spoon is called a: (a) convex mirror (b) plane mirror (c) concave mirror (d) concavo-plane mirror11. One statement is not correct for the plane mirror: (a) the image formed is upright (b) the image is equal in size (c) the image is real (d) the image is laterally inverted12. One is a luminous object: (a) the moon (b) book (c)chair (d)firefly13. The sound waves cannot pass through: (a) steel (b) wood (c) glass (d) vacuum14. The speed of sound in steel is: (a) 330 meters per second (b) 2100 meters per second (c) 1500 ,meters per second (d) 6000 meters per second


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15. Noise is a health hazard because it causes: (a) hearing loss (b) soothing effect (c) low blood pressure (d) nervous relaxation16. Sound waves travel most quickly through: (a) solids (b) gases (c) air (d) liquids17. Thefirstartificialsatellitewassentintospacein: (a) 1957 (b) 1939 (c) 1969 (d) 195218. Locating the position of objects with the help of a

satellite is called: (a) GRS (b) GMS (c) GPS (d) PGS19. Thefirstmaninspacewas: (a) Edwin Aldrin (b) Neil Armstrong (c) Dr. Sally Ride (d) Yuri Gagarin20. The Comet Halley appears after: (a) 50 years (b) 35 years (c) 60 years (d) 76 yearsPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (vibrate,infinity,effortarm,asteroids,comet)(i) Two ________ are seen from the earth without the help of a telescope.(ii) Aspaceobjectmadeofficeanddustparticlesisa ________.(iii) The air particles next to bell begin to ________ when the bell rings.


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(iv) The image of the object at ________ forms at the principal focus ‘F’ of the concave mirror.(v) The distance between the effort and fulcrum is called ________.• Answerthefollowingquestions. (5×10)22. (a) Where is the asteroid belt found? (3) (b) Write a detailed note on comets. (7)23. (a) When can comets be seen? (3) (b) What are the key milestones in space technology? (7)24. (a) How does sound move through solids more easily than it moves through air: (3) (b) How does sound travel? (7)25. (a) How many types of curved mirrors are there? (3) (b)Provethelawsofreflectionthroughanactivity. (7)26. (a) Which is the most important invention of the human history? (3) (b) Describe the two kinds of pulleys and their working. (7)


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. A nutcracker is an example of a: (a) screw (b) pulley (c) gear (d) liver2. Which system consists of at least two toothed

wheels? (a) lever system (b) pulley system (c) gear system (d) complex system3. The egg-beater consists of: (a) pulley system (b) screws (c) gear system (d) levers4. The steering wheel of motor vehicles is an example

of: (a) lever (b) pulley (c) wheel and axle (d) screw5. The chain of your bicycle is a: (a) pulley (b) lever (c) screw (d) wheel and axle6. One is a luminous object: (a) the moon (b) book (c)chair (d)firefly7. A mirror curved like the outside of the bowl of a

spoon is called a: (a) convex mirror (b) plane mirror (c) concave mirror (d) concavo-plane mirror


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(a) at ‘F’ (b) between ‘F’ and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’9. One statement is not correct for the plane mirror: (a) the image formed is upright (b) the image is equal in size (c) the image is real (d) the image is laterally inverted10. The distance between pole ‘P’ and principal focus

‘F’ of a concave mirror is called: (a) radius of curvature (b) radius of circle (c) focal length (d) center of curvature11. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy12. Plants uses solar energy falling on them: (a) 1/10th (b) les than 1/100th (c) 1/1000th (d) less than 1/10th13. Sound waves travel most quickly through: (a) solids (b) gases (c) air (d) liquids14. The sound waves cannot pass through: (a) steel (b) wood (c) glass (d) vacuum15. Noise is a health hazard because it causes: (a) hearing loss (b) soothing effect (c) low blood pressure (d) nervous relaxation


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16. The speed of sound in steel is: (a) 330 meters per second (b) 2100 meters per second (c) 1500 meters per second (d) 6000 meters per second17. The comet Halley appears after: (a) 50 years (b) 35 years (c) 60 years (d) 76 years18. Thefirstmaninspacewas: (a) Edwin Aldrin (b) Neil Armstrong (c) Dr. Sally Ride (d) Yuri Gagarin19. Thefirstartificialsatellitewassentintospacein: (a) 1957 (b) 1939 (c) 1969 (d) 195220. Locating the position of objects with the help of a

satellite is called: (a) GRS (b) GMS (c) GPS (d) PGSPart -B (Open Ended Questions) Marks: 7021. Fill in the blanks using following words. (2×5) (shadow, telephone, communication, driving wheel, screw driver)(i) A gear on which force is applied is called ________.(ii) A ________ is good example of wheel and axle.(iii) When an opaque object is placed in the path of light, a ________ is formed.(iv) You can talk to your friend at a long distance via ________.(v) ________ satellites move in geostationary orbit.


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• Answerthefollowingquestions. (5×10)22. (a) How do satellites tell us where we are: (3) (b) Describetheorbitsofartificialsatellites. (7)23. (a) What happens to most meteors? (3) (b) What do you know about Barringer Crater? (7)24. (a) How can one produce louder sounds? (3) (b) Prove that sound is form of energy. (7)25. (a) What is the ‘principal focus’ of a concave & a convex mirror? (3) (b) Describe in detail the image formation in curved mirrors. (7)26. (a) How do gears work in a wind-up clock? (3) (b) Write some uses of a wheel and axle in your daily life. (7)


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. A mirror curved like the outside of the bowl of a

spoon is called a: (a) convex mirror (b) plane mirror (c) concave mirror (d) concavo-plane mirror2. One is a luminous object: (a) the moon (b) book (c)chair (d)firefly3. A concave mirror forms a virtual image when the

object is present: (a) at ‘F’ (b) between ‘F; and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’4. The distance between pole ‘P’ and principal focus

‘F’ of a concave mirror is called: (a) radius of curvature (b) radius of circle (c) focal length (d) center of curvature5. One statement is not correct for the plane mirror: (a) the image formed is upright (b) the image is equal in size (c) the image is real (d) the image is laterally inverted6. The sound waves cannot pass through: (a) steel (b) wood (c) glass (d) vacuum7. Sound waves travel most quickly through: (a) solids (b) gases


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(c) air (d) liquids8. The speed of sound in steel is: (a) 330 meters per second (b) 2100 meters per second (c) 1500 ,meters per second (d) 6000 meters per second9. Noise is a health hazard because it causes: (a) hearing loss (b) soothing effect (c) low blood pressure (d) nervous relaxation10. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energy11. The most cheap fuel in the world is: (a) natural gas (b) coal (c) bio gas (d) oil12. Which system consists of at least two toothed

wheels? (a) lever system (b) pulley system (c) gear system (d) complex system13. A nutcracker is an example of a: (a) screw (b) pulley (c) gear (d) lever14. The egg-beater consists of: (a) pulley system (b) screws (c) gear system (d) levers15. The chain of your bicycle is a: (a) pulley (b) lever (c) screw (d) wheel and axle16. The steering wheel of motor vehicles is an example

of:


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(a) lever (b) pulley (c) wheel and axle (d) screw17. The Comet Halley appears after: (a) 50 years (b) 35 years (c) 60 years (d) 76 years18. Thefirstartificialsatellitewassentintospacein: (a) 1957 (b) 1939 (c) 1969 (d) 195219. Thefirstmaninspacewas: (a) Edwin Aldrin (b) Neil Armstrong (c) Dr. Sally Ride (d) Yuri Gagarin20. Locating the position of objects with the help of a

satellite is called: (a) GRS (b) GMS (c) GPS (d) PGSPart -B (Open Ended Questions) Marks: 7021. Fill in the blanks using following words. (2×5) (volume, vocal cords, orbit, load, translucent)(i) The path a planet follows around the sun is its _____.(ii) When you talk, air comes from the lungs and passes between the ________.(iii) The more an object vibrates, the louder the _____ will be.(iv) The point at which the lever lifts or moves objects is called ______.(v) Some material things allow some light to pass through and scatter the rest in many directions. The are called ________ materials.• Answerthefollowingquestions. (5×10)22. (a) How can you make your work easier, while


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using pulleys? (3) (b) Defineagearandwriteitscharacteristics. (7)23. (a) Describe three uses of a periscope. (3) (b) Describe the transmission, absorption and reflectionoflight. (7)24. (a) What are vocal cords? (3) (b) How do you produce sound? (7)25. (a) What are comets’ tails made of? (3) (b) Write a detailed note on comets. (7)26. (a) What is a satellite receiving station? (3) (b) Howdoesmultiplereflectionoccurina kaleidoscope? (7)


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Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy2. Plants use solar energy falling on them: (a) 1/10th (b) less than 1/100th (c) 1/1000th (d) less than 1/10th3. The Comet Halley appears after: (a) 50 years (b) 35 years (c) 60 years (d) 76 years4. Thefirstartificialsatellitewassentintospacein: (a) 1957 (b) 1939 (c) 1969 (d) 19525. Thefirstmaninspacewas: (a) Edwin Aldrin (b) Neil Armstrong (c) Dr. Sally Ride (d) Yuri Gagarin6. Locating the position of objects with the help of a

satellite is called: (a) GRS (b) GMS (c) GPS (d) PGS7. Sound waves travel most quickly through: (a) solids (b) gases (c) air (d) liquids8. Noise is a health hazard because it causes: (a) hearing loss (b) soothing effect


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(c) low blood pressure (d) nervous relaxation9. The sound waves cannot pass through: (a) steel (b) wood (c) glass (d) vacuum10. The speed of sound in steel is: (a) 330 meters per second (b) 2100 meters per second (c) 1500 ,meters per second (d) 6000 meters per second11. One is a luminous object: (a) the moon (b) book (c)chair (d)firefly12. One statement is not correct for the plane mirror: (a) the image formed is upright (b) the image is equal in size (c) the image is real (d) the image is laterally inverted13. A mirror curved like the outside of the bowl of a

spoon is called a: (a) convex mirror (b) plane mirror (c) concave mirror (d) concavo-plane mirror14. The distance between pole ‘P’ and principal focus

‘F’ of a concave mirror is called: (a) radius off curvature (b) radius of circle (c) focal length (d) center of curvature15. A concave mirror forms a virtual image when the

object is present:


130

(a) at ‘F’ (b) between ‘F; and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’16. A nutcracker is an example of a: (a) screw (b) pulley (c) gear (d) lever17. The steering wheel of motor vehicles is an example

of: (a) lever (b) pulley (c) wheel and axle (d) screw18. Which system consists of at least two toothed

wheels? (a) lever system (b) pulley system (c) gear system (d) complex system19. The chain of your bicycle is a: (a) pulley (b) lever (c) screw (d) wheel and axle20. The egg-beater consists of: (a) pulley system (b) screws (c) gear system (d) leversPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (effort arm, mechanical advantage, vibrate, volume, virtual)(i) The _______ shows how many times is the load greater than the effort.(ii) The distance between the effort and fulcrum is called ________.(iii) The image formed by a plane mirror is called a ______ image.(iv) The more an object vibrates, the louder the _______


131

will be.(v) The air particles next to bell begin to _______ when the bell rings.• Answerthefollowingquestions. (5×10)22. (a) How does a moveable pulley work? (3) (b) Describe the principle of a lever. (7)23. (a) What are luminous and no-luminous objects? (3) (b) Provethelawsofreflectionthroughanactivity. (7)24. (a) on the surface of the moon, astronauts cannot converse like on the earth. Why? (3) (b) How does sound travel? (7)25. (a) Who is an astronomer? (3) (b) Write a detailed note on comets. (7)26. (a) How are all sounds alike? (3) (b) What are the key milestones in space technology? (7)


132

Model Paper No-1Final Term (Units 1-13)


some space is: (a) atom (b) matter (c) element (d) mixture2. One metal is found in liquid state: (a) Ag (b) Na (c) Al (d) Hg3. PVC pipes contain: (a) phosphorous (b) chlorine (c) gold (d) mercury4. ‘Ink in water’ is an example of solution: (a) solid in liquid (b) liquid in gas (c) liquid in liquid (d) gas in liquid5. Carbon dioxide dissolves in water to make: (a) lemonade (b) fruit squash (c) soda water (d) lassi6. Shaving cream and emulsion paint are: (a) suspensions (b) solvents (c) solutes (d) colloids7. Thick blanket of air around the earth is: (a) earth cover (b) atmosphere (c) wind (d) earth’s coat8. Harmful ultraviolet rays of the sun are blocked

by: (a) nitrogen of the air (b) ozone of the air


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(c) helium of the air (d) clouds9. Percentage of CO2 in air is about: (a) 0.01% (b) 0.02% (c) 0.03% (d) 0.04%10. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energy11. The most cheap fuel in the world is: (a) natural gas (b) coal (c) biogas (d) oil12. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy13. A nutcracker is an example of a: (a) screw (b) pulley (c) gear (d) lever14. Which system consists of at least two toothed

wheels? (a) lever system (b) pulley system (c) gear system (d) complex system15. The egg-beater consists of: (a) pulley system (b) screws (c) gear system (d) levers16. One is a luminous object: (a) the moon (b) book (c)chair (d)firefly17. A mirror curved like the outside of the bowl of a

spoon is called a: (a) convex mirror (b) plane mirror (c) concave mirror (d) concavo-plane mirror


134


(a) at ‘F’ (b) between ‘F; and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’19. Sound waves travel most quickly through: (a) solids (b) gases (c) air (d) liquids20. The Comet Halley appears after: (a) 50 years (b) 35 years (c) 60 years (d) 76 yearsPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (residue, salt, rare gases, suspension, solution)(i) Sodium chloride is a _______.(ii) Duringfiltration,thesubstancewhichremainson thefilterpaperiscalled________.(iii) Argon, neon and helium are _______.(iv) A ________ is a mixture in which its components are evenly mixed.(v) Some medicines are available in a ______ form.• Answerthefollowingquestions. (5×10)22. (a) How is ice-cream a mixture? (3) (b) Defineacompound.Giveexamplesanddescribe properties of compounds. (7)23. (a) What is smog? (3) (b) Prove the presence of carbon dioxide in air through an activity. (7)24. (a) Give two examples of solid in solid solution. (3) (b) What is solubility? How does temperature affect


135

the solubility? (7)25. (a) Name of the kind of energy in a body due to its motion. (3) (b) Defineandexplainthelawofconservationof energy. (7)26. (a) What is the principle of a lever? (3) (b) Defineagearandwriteitscharacteristics. (7)


136


Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. What is the percentage of non-metal elements? (a) 30 (b) 40 (c) 60 (d) 702. The process shown in the equation solid vapour: (a)filtration (b)sublimation (c) distillation (d) chromatography3. A new thing formed in a chemical reaction of

elements is called: (a) mixture (b) atom (c) compound (d) reactant4. Urea- a fertilizer, is made with the help of: (a) air (nitrogen) (b) air (oxygen) (c) air (carbon dioxide) (d) air (water vapour)5. Rockets use, during their space journeys: (a) liquid oxygen (b) liquid nitrogen (c) liquid hydrogen (d) liquid carbon dioxide6. A solution in which water is the solvent is known

as: (a) saturated solution (b) aqueous solution (c) dilute solution (d) concentrated solution7. One is an example of suspension: (a) “snowfall” inside a paper weight


137

(b) blood (c) smoke (d) fog8. The substances in lesser amount in a solution is a: (a) colloid (b) suspension (c) solute (d) solvent9. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy10. Plants use solar energy falling on them: (a) 1/10th (b) less than 1/100th (c) 1/1000th (d) less than 1/10th11. The steering wheel of motor vehicles is an example

of: (a) lever (b) pulley (c) wheel and axle (d) screw12. The chain of your bicycle is a: (a) pulley (b) lever (c) screw (d) wheel and axle13. One statement is not correct for the plane mirror: (a) the image formed is upright (b) the image is equal in size (c) the image is real (d) the image is laterally inverted14. The distance between pole ‘P’ and principal focus

‘F’ of a concave mirror is called: (a) radius off curvature (b) radius of circle (c) focal length (d) center of curvature


138

15. Noise is a health hazard because it causes: (a) hearing loss (b) soothing effect (c) low blood pressure (d) nervous relaxation16. The sound waves cannot pass through: (a) steel (b) wood (c) glass (d) vacuum17. The speed of sound in steel is: (a) 330 meters per second (b) 2100 meters per second (c) 1500 ,meters per second (d) 6000 meters per second18. Thefirstartificialsatellitewassentintospacein: (a) 1957 (b) 1939 (c) 1969 (d) 195219. Thefirstmaninspacewas: (a) Edwin Aldrin (b) Neil Armstrong (c) Dr. Sally Ride (d) Yuri Gagarin20. Locating the position of objects with the help of a

satellite is called: (a) GRS (b) GMS (c) GPS (d) PGSPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (comet, orbit, virtual, sound, load)(i) The path a planet follows around the sun is its _____.(ii) Aspaceobjectmadeofficeanddustparticlesisa ________.(iii) Loud ________ is an unpleasant sound.(iv) The image formed by a plane mirror is called a ______ image.


139

(v) The point at which the lever lifts or moves objects is called ______.• Answerthefollowingquestions. (5×10)22. (a) What are luminous and no-luminous objects? (3) (b) Describe in detail the image formation in curved mirrors. (7)23. (a)Whatistheregularreflectionoflight? (3) (b)Provethelawsofreflectionthroughanactivity. (7)24. (a) What is sound? (3) (b) Prove the sound is a form of energy. (7)25. (a) Where is the asteroid belt found? (3) (b) Write a detailed note on comets. (7)26. (a) What happens to most meteors? (3) (b)Describetheorbitsofartificialsatellites. (7)


140


Time Allowed: 2:00 Hours Total Marks: 100Part -A (Multiple Choice Questions)• Circletheoptionofthebestanswer. (2×20)1. The word atom has its origin from: (a) Chinese (b) English (c) Roman (d) Greek2. A glucose molecule has __________ atoms. (a) 20 (b) 24 (c) 12 (d) 63. One is not an element: (a) magnesium (b) phosphorous (c) potassium (d) water4. Thick blanket of air around the earth is: (a) earth cover (b) atmosphere (c) wind (d) earth’s coat5. Harmful ultraviolet rays of the sun are blocked

by: (a) nitrogen of the air (b) ozone of the air (c) helium of the air (d) clouds6. Percentage of CO2 in air is about: (a) 0.01% (b) 0.02% (c) 0.03% (d) 0.04%7. ‘Ink in water’ is an example of solution: (a) solid in liquid (b) liquid in gas (c) liquid in liquid (d) gas in liquid8. Carbon dioxide dissolves in water to make: (a) lemonade (b) fruit squash (c) soda water (d) lassi


141

9. The amount of solute in grams, dissolved in 100 cm3 of the solvent at a given temperature is called as its:

(a) speed of dissolving (b) solution (c) suspension (d) solubility10. All orbiting planets possess: (a) potential energy (b) kinetic energy (c) sound energy (d) electrical energy11. The most cheap fuel in the world is: (a) natural gas (b) coal (c) bio gas (d) oil12. A stretched rubber band has: (a) heat energy (b) sound energy (c) kinetic energy (d) potential energy13. A nutcracker is an example of a: (a) screw (b) pulley (c) gear (d) lever14. Which system consists of at least two toothed

wheels? (a) lever system (b) pulley system (c) gear system (d) complex system15. The egg-beater consists of: (a) pulley system (b) screws (c) gear system (d) levers16. One is a luminous object: (a) the moon (b) book (c)chair (d)firefly17. A mirror curved like the outside of the bowl of a


142

spoon is called a: (a) convex mirror (b) plane mirror (c) concave mirror (d) concavo-plane mirror18. A concave mirror forms a virtual image when the

object is present: (a) at ‘F’ (b) between ‘F; and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’19. Sound waves travel most quickly through: (a) solids (b) gases (c) air (d) liquids20. Noise is a health hazard because it causes: (a) hearing loss (b) soothing effect (c) low blood pressure (d) nervous relaxationPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (vocal cords, communication, mechanical, advantage,centreofcurvature,flashinglights.)(i) ________ satellites move in geostationary orbit.(ii) When you talk, air comes from the lungs and passes between the ________.(iii) The center of a curved mirror is called _____.(iv) The _______ shows how many times is the load greater than the effort.(v) In the sea, the ________ are used to warn the ships of dangerous rocks.• Answerthefollowingquestions. (5×10)22. (a) Which form of energy is present in wood, gas and petrol? (3)


143

(b) Definethe“lawofconservationofenergy”.(7)23. (a) Which is the most important invention of the human history? (3) (b) Describe the two kinds of pulleys and their working. (7)24. (a) How is air pressure measured? (3) (b) Write some uses of oxygen in our daily life. (7)25. (a) Howisairfilteredbeforeenteringyourbody? (3) (b) Describe physical properties of metal elements. (7)26. (a) What is a wind vane? (3) (b) What is the atmosphere? Describe its layers in detail. (7)


144



some space is: (a) atom (b) matter (c) element (d) mixture2. One metal is found in liquid state: (a) Ag (b) Na (c) Al (d) Hg3. One is not a mixture: (a) air (b) salad (c) sugar (d) ice-cream4. Urea- a fertilizer, is made with the help of: (a) air (nitrogen) (b) air (oxygen) (c) air (carbon dioxide) (d) air (water vapour)5. Rockets use, during their space journeys: (a) liquid oxygen (b) liquid nitrogen (c) liquid hydrogen (d) liquid carbon dioxide6. Percentage of CO2 in air is about: (a) 0.01% (b) 0.02% (c) 0.03% (d) 0.04%7. A solution in which water is the solvent is known

as: (a) saturated solution (b) aqueous solution (c) dilute solution (d) concentrated solution


145

8. One is an example of suspension: (a) “snowfall” inside a paper weight (b) blood (c) smoke (d) fog9. The substances in lesser amount in a solution is a: (a) colloid (b) suspension (c) solute (d) solvent10. We eat food cooked by: (a) sound energy (b) heat energy (c) sunlight energy (d) wind energy11. Plants use solar energy falling on them: (a) 1/10th (b) less than 1/100th (c) 1/1000th (d) less than 1/10th12. The steering wheel of motor vehicles is an example

of: (a) lever (b) pulley (c) wheel and axle (d) screw13. The chain of your bicycle is a: (a) pulley (b) lever (c) screw (d) wheel and axle14. The egg-beater consists of: (a) pulley system (b) screws (c) gear system (d) levers15. One statement is not correct for the plane mirror: (a) the image formed is upright (b) the image is equal in size (c) the image is real (d) the image is laterally inverted


146

16. The distance between pole ‘P’ and principal focus ‘F’ of a concave mirror is called:

(a) radius off curvature (b) radius of circle (c) focal length (d) center of curvature17. A concave mirror forms a virtual image when the

object is present: (a) at ‘F’ (b) between ‘F; and ‘C’ (c) at ‘C’ (d) between ‘F’ and ‘P’18. The Comet Halley appears after: (a) 50 years (b) 35 years (c) 60 years (d) 76 years19. Thefirstmaninspacewas: (a) Edwin Aldrin (b) Neil Armstrong (c) Dr. Sally Ride (d) Yuri Gagarin20. Locating the position of objects with the help of a

satellite is called: (a) GRS (b) GMS (c) GPS (d) PGSPart -B (Open Ended Questions) Marks: 7021. Fillintheblanksusingfollowingwords. (2×5) (substance, tensil strength, dilute, active air, wind energy)(i) ________ is the ability of a matter to bear a lot of strain without breaking.(ii) The word __________ refers to a particular kind of things.(iii) Oxygen is often referred to as ________.(iv) The solution in which the quantity of solute is


147

relatively less is known as a __________ solution.(v) ________ is the ability to do work.• Answerthefollowingquestions. (5×10)22. (a) What are energy convertors? (3) (b) Write a note on ‘energy transfer in an environment’. (7)23. (a) What is a pulley? (3) (b) Describe the principle of a lever. (7)24. (a) Whataretheusesofirregularreflectioninour everyday life? (3) (b) Howdoesmultiplereflectionoccurina kaleidoscope? (7)25. (a) What is the speed of sound while passing through water at room temperature? (3) (b) How does sound travel? and How do you produce sound? (7)26. (a) What are comets’ tails made of? (3) (b) Write a detailed note on comets. (7)


148

1st Term

WEEK UNIT # NAME of UNIT PAGE #

Ist 1

WHAT IS SCIENCE? ( 1.1 to 1.4) / Safety

Rules In The Laboratory / Introduction of

Few Science Personalities / Unit Review /

MCQs / Detailed Questions

3 to 12

2nd 2

CELLULAR ORGANIZATION OF PLANTS AND

ANIMALS ( 2.1 to 2.6) / Activities 2:1 & 2:2

/ Unit Review / MCQs / Detailed Questions

13 to 22

3rd Revision and Test of the above topics (Units 1 & 2)

4th 3

OUR SENSE ORGANS ( 3.1 to 3.5) / Activity

3:1 / Unit Review / MCQs / Detailed

Questions / Identify & Label

23 to 28

5th 4HOW PLANTS STAY ALIVE ( 4.1 to 4.6) /

Unit Review / MCQs / Detailed Questions29 to 36

6th Revision and Test of the above topics (Units 3 & 4)

7th 5

LIVING THINGS AND THEIR ENVIRONMENT

( 5.1 to 5.6) / Unit Review / MCQs /

Detailed Questions

37 to 44

8th Revision and Test of the above topics (Unit 5)

9th Preparatory Tests' Week

10th 1st Term Paper (Units 1 to 5) ORAL

11th 1st Term Paper (Units 1 to 5) WRITTEN


149


12th 6

THE HIDDEN STRUCTURE OF MATTER

(Atoms, Molecules, Mixtures and

Compounds) ( 6.1 to 6.6) / Activities 7:1 to


Questions

45 to 58

13th 7

AIR / ( 7.1 to 7.4) / Activities 7:1 & 7:2 /

Unit Review / MCQs / Detailed Questions /

Identify & Label

59 to 68


15th 8

SOLUTIONS, SUSPENSIONS AND COLLOIDS (

8.1 to 8.6) / Activity 8:1 / Unit Review /

MCQs / Detailed Questions / Identify & Label

69 to 76

16th 9INTRODUCTION TO ENERGY AND ITS

FORMS ( 9.1 to 9.5) 77 to 81


18th "( 9.6 to .9) / Activities 9:1 & 9:2 / Unit

Review / MCQs / Detailed Questions82 to 86


20th Preparatory Tests' Week

21st 2nd Term Paper (Units 6 to 9) ORAL

22nd 2nd Term Paper (Units 6 to 9) WRITTEN


150

3rd Term


23rd 10

PUTTING ENERGY TO WORK: MACHINES (

10.1 to 10.5) / Unit Review / MCQs /

Detailed Questions

87 to 94

24th 11 BEHAVIOUR OF LIGHT( 11.1 to 11.5) 95 to 99


26th "

( 11.6 to 11.10) / Activity 11:1 / Unit

Review / MCQs / Detailed Questions

/Indentify & Label

100 to 108

27th 12SOUND AROUND US ( 12.1 to 12.6) / Unit


28th 13EXPLORING SPACE ( 13.1 & 13.2) / Unit


29th Revision and Test of the above topics (Units 11, 12 & 13)

30th Preparatory Tests' Week 1st & 2nd Term (Units 1 to 9)

31st Preparatory Tests' Week 3rd & 4th Term (Unit s 10 to 13)

32nd 3rd Term Paper (Units 1 to 13) (ORAL)

33rd 3rd Term Paper (Units 1 to 13) (WRITTEN)

34th "

NOTE : Teachers may synchronize this "Scheme of Study" with our (Term Wise ) "Model Papers", according to their specific needs.


151

40 weeks 5/6 days a week Four Terms1st Term


Ist 1

WHAT IS SCIENCE? ( 1.1 to 1.4) / Safety

Rules In The Laboratory / Introduction of

Few Science Personalities / Unit Review /

MCQs / Detailed Questions

3 to 12

2nd 2

CELLULAR ORGANIZATION OF PLANTS AND

ANIMALS ( 2.1 to 2.6) / Activities 2:1 & 2:2

/ Unit Review / MCQs / Detailed Questions

13 to 22


4th 3

OUR SENSE ORGANS ( 3.1 to 3.5) / Activity


Questions / Identify & Label

23 to 28

5th 4HOW PLANTS STAY ALIVE ( 4.1 to 4.6) /

Unit Review / MCQs / Detailed Questions29 to 36


7th 5

LIVING THINGS AND THEIR ENVIRONMENT

( 5.1 to 5.6) / Unit Review / MCQs /

Detailed Questions

37 to 44


9th 1st Term Paper (Units 1 to 5) ORAL

10th 1st Term Paper (Units 1 to 5) WRITTEN

2nd Term


11th 6





Questions

45 to 58

12th 7



Identify & Label

59 to 68


14th 8



MCQs / Detailed Questions / Identify &

Label

69 to 76


FORMS ( 9.1 to 9.5) 77 to 81





19th 2nd Term Paper (Units 6 to 9) ORAL

20th 2nd Term Paper (Units 6 to 9) WRITTEN


152

2nd Term


11th 6





Questions

45 to 58

12th 7



Identify & Label

59 to 68


14th 8



MCQs / Detailed Questions / Identify &

Label

69 to 76


FORMS ( 9.1 to 9.5) 77 to 81





19th 2nd Term Paper (Units 6 to 9) ORAL

20th 2nd Term Paper (Units 6 to 9) WRITTEN

3rd Term


21st 10

PUTTING ENERGY TO WORK: MACHINES (

10.1 to 10.5) / Unit Review / MCQs /

Detailed Questions

87 to 94

22nd 11 BEHAVIOUR OF LIGHT( 11.1 to 11.5) 95 to 99


24th "

( 11.6 to 11.10) / Activity 11:1 / Unit

Review / MCQs / Detailed Questions

/Indentify & Label

100 to 108

25th 12SOUND AROUND US ( 12.1 to 12.6) / Unit


26th 13EXPLORING SPACE ( 13.1 & 13.2) / Unit


27th Revision and Test of the above topics (Units 11, 12 & 13)

28th 3rd Term Paper (Units 10 to 13) (ORAL)

29th 3rd Term Paper (Units 10 to 13) (WRITTEN)

30th "


153

4th Term


31st1st TERM

(REVISION) UNITS 1 to 3 3 to 28

32nd " UNITS 4 & 5 29 to 44

33rd Preparatory Tests' Week (1st Term)

34th2nd TERM

(REVISION) UNITS 6 & 7 45 to 68

35th " UNITS 8 to 9 69 to 86

36th Preparatory Tests' Week (2nd Term)

37th3rd TERM

(REVISION) UNITS 10 & 13 87 to 120

38th " Preparatory Leaves' Week

39th 4th Term Paper (Units 1 to 13) (ORAL)

40th 4th Term Paper (Units 1 to 13) (WRITTEN)

NOTE : Teachers may synchronize this "Scheme of Study" with our (Term Wise ) "Model Papers", according to their specific needs.

Science - Gohar Publishers · Ans: Isaac Newton presented “Law of motion”. Q6. Who invented the...

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Transcript of Science - Gohar Publishers · Ans: Isaac Newton presented “Law of motion”. Q6. Who invented the...