The City SchoolUniversity Road Campus Science Question Bank

Class : 7

Chapter From Cells to Organisms

Q1. The picture below shows a cat and an amoeba

To which group of living organisms do they belong?

__________________________________________________________________________

Write down the difference between these groups of living organism.

_________________________________________________________________________________________

______________________________________________________________________________________

Q2. a) Name and label the parts of the cells given in the diagrams

___________________

_________________

b) Write down the differences between these two cells____________________________________________________________________________________________________________________________________________________________________________________

c) Write down the function of the following parts of the cell

Part of cell Function Part of cell Function

Cell wall

Cell membrane

Mitochondria

Starch grain

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Nucleus

Cytoplasm

Vacuole

Chloroplast

Nuclear Membrane

Q4. Label the diagram of microscope

Write the function of

i) Eye piece ____________________________________ii) Mirror ___________________________________iii) Coarse adjustment Screw __________________________________iv) Objective lens ______________________________

v) Draw tube ______________________________vi) Fine adjustment screw _________________________________________________vii) Stage __________________________________________________________________

Q1. The drawing below shows a root hair cell.

Give two substances that root hair cells absorb from the soil.

1. .............................................................

2

2..............................................................

Q2. The diagram below shows some cells.

(a) (i) Give the letters of the two plant cells in the diagrams.

............... and...............

(ii) Which one of these plant cells contains chloroplasts?Give the letter.

...............

(iii) Give the function of chloroplasts.

.............................................................................................................

.............................................................................................................

(b) Give the letter of the cell which transfers genetic information from father to offspring.

...............

3. (a) The diagram shows a group of cells from the lining of the mouth.

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(i) Give the name and function of part P.

Name of part P

.............................................................................................................

1

Function of part P

.............................................................................................................

.............................................................................................................

Chapter Elements and Compounds:

Q1.Choose the best answer.1. Which of the following is an element?a) steam b) sugar c)dry ice d) sulphur

2. Which of the following is an element but NOT a metal?a) Oxygen b) copper c) aluminium d) salt

3. Which element can be found as charcoal, diamond or graphite?a) Carbon b) nitrogen c) zinc d) phosphorus

4. Which metal is present in the liquid state at room temperature?a) Helium b) bromine c) mercury d) lithium

5. Which substance does not have fixed melting and boiling points?a) Water b) sugar c) ink d) sodium

6. Which of the following best supports the fact that air is a mixture?a) The oxygen in the air is easily removed during combustion.b) Air contains different elements.c) The water vapour is a chemical compound.d) The composition of the air remains almost constant throughout the world.

7. A compound contains a) Different kinds of atoms mixed together.b) The same kind of atom mixed together.c) Different kinds of atoms chemically combined together.d) The same kind of atom chemically combined together.

Q2. Fill in the blanks.a) Elements are classified into metals,__________ and __________b) A _____________ is a substance which can not further divide by chemical reaction.c) The most found element in the air is_______________d) In the periodic table, elements are arranged in columns called______________

Q3. Complete the given statements.(a)Rust is formed when iron objects are left out in the air. The iron reacts with the oxygen in the air, forming iron oxide. Rust be can turned back into iron, by mixing it with carbon and heating it. I think rust is

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_____________________ (an element / a mixture / a compound) because ______________________________________________________________________________

(b)Helium is a gas. There are tiny amounts of helium in the air. Helium does not burn, and will not react with any other chemicals. It cannot be split up by chemical reactions. It think helium is _____________________ (an element / a mixture / a compound) because ______________________________________________________________________________

Q4. Match the Columns.A B

1) A Compound used in photosynthesis a) Mercury

2) An element present both in air and water b) Helium

3) A metal which is liquid at room temperature c) Carbon dioxide

4) A metal used for making cooking pot d) Aluminum

5) A non metal used in air balloon e) oxygen

Q5. Are these statements true or false. Rewrite the false statement. a) Elements are made of two or more different types of atoms.___________________________________________________________________________b) Mixtures have a definite composition.___________________________________________________________________________c) Compounds can be represented using a formula.___________________________________________________________________________d) A mixture of salt and water will boil at a higher temperature than pure water.___________________________________________________________________________e) Compounds can be decomposed on heating.___________________________________________________________________________f) The two most abundant elements in the Universe are Hydrogen & Helium.___________________________________________________________________________g) Chemical symbol for Copper is Co.___________________________________________________________________________h) Vertical columns in the periodic table are called periods.___________________________________________________________________________i) Elements in the same group in the periodic table share similar chemical properties.___________________________________________________________________________j) Compounds can only be broken into simpler substances by chemical reactions.___________________________________________________________________________

Q6a. Complete the following table:Compounds Elements they are made of Models of Compound

(i) Water

(ii) Carbon Dioxide

(iii) Ammonia

(iv) Iron Sulphide

(v) Sulphur Dioxide

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b. Classify the following as Elements (Metals and non-metals)and compound.Carbondioxide, Iron, Sulphur, Helium, Nitrogen, Copper Sulphate, Copper, Oxygen, Aluminium, Carbon

ElementsCompounds

Metals Non-metals

c. Write two properties on the basis of which you differentiate metals from non-metals. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________d. The formula of Aluminium sulphate is Al2(SO4)3

i) How many elements are present in the above formula. __________________________________________________________________________ii) State the number of atoms of each element. __________________________________________________________________________ __________________________________________________________________________e.When Magnesium burns in air a white ash is formed.i) Write a word equation for the reaction __________________________________________________________________________ __________________________________________________________________________ii) Is this a physical or a chemical change? Give two reasons. __________________________________________________________________________Q7. When copper carbonate is heated copper oxide and a gas are formed. The gas when passed through lime water turns it milky as shown in the diagram below.

i) Which gas is produced that turns lime water milky? __________________________________________________________________________

ii) Write a word equation for the above reaction. __________________________________________________________________________

Q8. An alloy is a mixture of elements.

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The table shows the mass of each element present in 100 g of five different alloys, bronze, solder, steel, stainless steel and brass.

(a) Which alloy in the table above contains an element which is a non-metal?

______________________________________________________________________________(b) Which two alloys in the table contain only two metals?____________________________________ and ______________________________________

(c) Another alloy called nichrome contains only the elements chromium and nickel. 100 g of nichrome contains 20 g of chromium. How much nickel does it contain? _______________ gQ9. Identify each of the following picture as an element E or a compound C.

Q10. Below is the first 36

elements in the periodic table with their atomic numbers.(a) Give the symbol for one example of each of the

following:(i) a metal .............................(ii) an inert gas.......................(iii)a non-metal in liquid state.............................(b) Find chlorine in the table above. (i) What is the atomic number of Chlorine? ..................... (ii) What is the group number................................?

Q11. Different elements have different properties, some of which are shown below:• Electrical insulator • Good thermal conductor• Poor thermal conductor • High melting point • Good electrical conductor • Shiny• Ductile • Malleable

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a) Gold is a metal. Give two properties of gold from the list above which make it a good material to use as jewellery. 1 ...............................................................................................................................2 ...............................................................................................................................b) Krypton is a gas used inside a light bulb. Give two properties of krypton from thelist above which make it a good material to use. 1 ...............................................................................................................................2 ...............................................................................................................................c) Tungsten is used to make the filament inside a light bulb. Give two propertiesfrom the list above which make it a good material to use. 1 ...............................................................................................................................2 ...............................................................................................................................Q12.A science teacher showed her class three experiments, A, B and C. The experiments and the word equations for the reactions that took place are shown below. All the experiments were done in a fume cupboard.

(a) From the substances in experiments A, B and C, above, give the name of:(i) three metallic elements; __________________________________________________(ii) three non-metallic elements; ______________________________________________(iii) two compounds. ________________________ and ________________________

(b) In experiment B, the iron filings weighed 2.0 g at the beginning of the experiment and the iron sulphide produced weighed 2.8 g.Explain this increase in mass.____________________________________________________________________________________________________________________________________________________________

(c) Complete the word equation for the chemical reaction in experiment C.copper + chlorine → ____________________________

Q-1: Fill in the blanks with suitable answers.1. Electrolysis is a process in which is passed through water to break it into its

constituent elements.2. While cells are the building blocks of living things, are the building

blocks of all matter, including living and non-living things.3. Cells themselves are made up of different or materials containing elements.4. Currently there are

man made.elements, of which are found naturally and the rest are

5. Stars are made up of two most abundant elements in the universe, and .

6. The most abundant element in our universe is .7. The most abundant element by mass in the Earth’s crust and in the human body

is .8. Some elements are named after the scientists who discovered them for e.g. Einsteinium and

e.tc.9. A chemical reaction is a process in which substances are formed.

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10. The physical properties of elements are their; appearance, state, colour, density, boiling and melting points, conductivity.

11. The Russian scientist Dmitri Ivanovich (1834-1907) was the first to arrangethe known elements during his time, in the Periodic Table.

12. The vertical columns in the Periodic Table are called and the horizontal

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rows are called .13. Going across a period from left to right, elements change

from being to in character.14. Liquid nitrogen is used as a agent.15. is a metal which is not solid at room temperature, it is semi solid/liquid.16. A non metal conducts electricity well like metals.

Q.2-Encircle the best answer from the given options.

1.The elements have same properties in A period A group

2.The elements that have properties of metals and non metals both are called Metalloids Metallic elements

3.Solid carbon dioxide is called Dry gas Dry ice

4.A compound is a/an Impure substance Pure substance

5.Burning, heating and electrolysis are examples of Physical change Chemical reaction

6.Distilled water is A compound A mixture

7.Muddy water is an example of compound mixture

8.Mixtures are Pure substances Impure substances

Q.4 (a ) Give reasons.Why,1. Helium gas is used to fill airships and balloons.2. Copper is used to make electrical wires.3. Oxygen gas is filled in tanks for scuba diving.4. The early scientists called Alchemists tried to make gold but failed in their attempts.5. 1 gm of Hydrogen combines with 8 gm of Oxygen to form 9 gm of water. If there is 5 gm

Hydrogen and 50 gm of Oxygen only 45 gm of water will be formed.

Chapter Mixtures

solvent • solution • solute • insoluble • soluble • dissolving solid • liquid • dissolved

1 Use the words in the box above to complete this paragraph.

When we put sugar into tea it disappears! We can taste it but we can’t see it, we say it has

_____________. For _____________ to take place we need a _____________, which is generally a liquid,

and a _____________, which is generally a solid. If the _____________ particles will not dissolve in the

liquid then we say it is _____________.

If the solid particles do dissolve in the _____________ we say it is _____________.

Once a solid has dissolved in a liquid we say we have a _____________.

2 This table shows the mass of potassium chloride that dissolves in 100 g of water at different temperatures.Temperature (°C) Mass of potassium chloride that

dissolves in 100 g of water 0 2710 3220 3530 3840 4150 4460 4770 5080 5290 54100 56

i) Use the above data and plot a graph on your graph paper.

ii) With the help of graph can you explain what happens to the particles of potassium chloride when they dissolve in the water?

__________________________________________________________________________________________________________________________________________________________________________

3 Imagine you are on a desert island. You need salt, but all the salt has been spilt on the beach. How would you get pure salt from the mixture of salt and sand?

_____________________________________________________________________________________

_____________________________________________________________________________________

Objective

Q.1 MCQs

1) A process to separate insoluble solid from liquid is

a) Evaporation b) Filtration

c) Condensation d) Crystallization

2) Gases from the air can be separated by

a) Filtration b) Distillation

c) Fractional distillation d) Chromatography

3) A process for the separation of colour pigments is

a) Distillation b) Evaporation

c) Chromatography d) Freezing

4) Petrol from the crude oil can be obtain through

a) Chromatography b) Fractional distillation

c) Solar distillation d) Simple distillation

5) Air is a type of

a) Gases b) Mixture

c) Compound d) Elements

6) Brass is an alloy of

a) Copper and Zinc b) Copper and Tin

c) Iron and Copper d) Zinc and Silver

7) Diamond is an example of

a) Alloy b) Element

c) Mixtures d) Compound

8) Which of the following separation technique has been used to separate more than two liquids with

different boiling points?

a) Chromatography b) Distillation

c) Fractional Distillation d) Evaporation.

9) What is the residue obtained when sand and salts solution is filtered?

a) Sand b) Salt

c) Water d) No Residue

10) Which of the following are mixtures?

i) Air ii) Distilled water iii) Fizzy drink iv) Bronze

a) (i) and (ii) only b) (i) (ii) and (iii) only

c) (i) (ii) and (iv) only d) (i) (iii) and (iv) only

Q2. State whether True or False. Correct the false statement.

i) Chalk in water can be separated by filtration. [ ]

___________________________________________________________________________

ii) Police scientists use chromatography to solve crimes. [ ]

___________________________________________________________________________

iii) Alcohol and water can be separated easily by fractional distillation. [ ]

___________________________________________________________________________

iv) Distillation involves boiling and condensation. [ ]

___________________________________________________________________________

v) Pure water boils at different temperatures in different parts of earth. [ ]

___________________________________________________________________________

Q3. Match the Column.

Column A Column B

Chromatography insoluble solid

Evaporation 100 °C

Condensation Blood

Distillation Liquid gases

Filtration Distilled water

Q4. Match the following gases in air with the percentage composition and write the answer in column ‘C’.

Gases in Air (A) Percentage Composition (B) Column ‘C’

(i) Oxygen (a)78%

(ii) Carbon Dioxide (b)Variable

(iii) Nitrogen (c)21%

(iv) Rare Gases (d)0.03%

(v) Water Vapours (e) 1%

Q5. Name the method by which you will separate the following mixtures:

(i) Iron Filings & Sulphur _________________________________________

(ii) Different Coloured Dyes _________________________________________

(iii) Ink & Water _________________________________________

(iv) Sand & Salt in Water _________________________________________

(v) Different Gases in Air _________________________________________

Q6a. State whether air & water are mixtures or compounds. Justify your answers giving two reasons for each._______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________b. Hydrogen is the lightest element. However, Helium is used in hot air balloons instead of Hydrogen. Explain.______________________________________________________________________________________________________________________________________________________

Q7. Susie used chromatography to identify the coloured substances in the ink from a felt-tip pen. She used:

green ink

blue ink

purple ink

ink from her felt-tip pen.

She used water as the solvent.

Look at the diagram above.

(a) (i) Which colours were present in the ink from the felt-tip pen.

______________________________________________________________________________

(ii) How many coloured substances were there in green ink? How can you tell?

_____________________________________________________________________________________

_______________________________________________________________________

(iii) Susie placed the spots of ink on a line on the chromatography paper as shown in the

diagram. To draw the line, Susie had to choose a felt-tip pen or a pencil.

Which one should she use?

_____________________________________________________________________________________

_______________________________________________________________________

(iv) Give the reason for your answer.

_____________________________________________________________________________________

______________________________________________________________________

(b) Susie used water as the solvent in this experiment.

When she repeated the experiment with a different set of pens, it did not work.

She then used ethanol instead of water.

Suggest why the experiment worked with ethanol but not with water.

_____________________________________________________________________________________

_______________________________________________________________________

Q8. Chris collected some sea water near a beach. The sea water had salt dissolved in it. It had sand mixed in it.

(a) Chris separated the sand from the salt water as shown below (i) What is this method of separation called? [1] Tick the correct box.

Chromatography distillation

filtration magnetism

(ii) What is substance A? __________________________________________________(iii) What is the part labelled B ? ____________________________________________

(b) Chris poured some of the salt water from the flask into a dish.He put the dish on a balance and left it in a warm room for a week.

(i) Look at the two readings on the balance. Work out the decrease in mass: ________g(ii) After one week there was a white solid but no liquid in the dish. What had happened to the water in the dish? _________________________________________________________________(iii) What was the white solid left in the dish? _________________________________________________________________

Solutions WorksheetOn the line at the left, write the letter of the definition that best matches each term. 1. solution

2. solute

3. Solvent

4. soluble

5. alloy

6. aqueous solution

7. electrolyte

a. capable of being dissolved

b. solution with water as the solvent

c. substance that is dissolved in a solution

d. substance that dissolves in water to form a solution that conducts an electric current

e. solid solution containing two or more metals

f. homogeneous mixture of two or more substances in a single physical state

g. substance that does the dissolving in a solution

Answer each of the following questions in the space provided.8. Describe the properties of a solution

9. Give two examples of solutions in nature and explain why each is important.

10. Describe how a chemist can accurately prepare a solution of precise molarity.

Answer each of the following questions in the space provided.

concentration molarity molality

saturated unsaturated supersaturated

10. is the concentration of a solution expressed as the number of moles of solute dissolved in each liter of solution.

11. A solution contains as much solute as can possibly be dissolved under existing conditions of temperature and pressure

12. The amount of solute in a given amount of solvent or solution is the of a solution.

13. A solution that contains more solute particles than are needed to form a saturated solution is .

14. The of a solution is the number of moles of solute dissolved in each kilogram of solvent.

15. A solution that has less than the maximum amount of solute that can be dissolved is called a(n) solution.

Solve each of the following problems as directed. Show all your work.

16. What is the molarity of the solution formed by mixing 0.20 mol of sodium hydroxide with enough water to make 150 ml of solution?

1. What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3?

2. A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? Would the piece of wood float in water? 

3A cup of gold colored metal beads was measured to have a mass 425 grams. By water displacement,

the volume of the beads was calculated to be 48.0 cm3. Given the following densities, identify the metal. Gold: 19.3 g/mLCopper: 8.86 g/mLBronze: 9.87 g/mL

4. An ice cube measuring 5.80 cm by 5.80 cm by 5.80 cm has a density of 0.917 g/ml. What is the mass?

5. The density of aluminum is 2.70 g/ml. If the mass of a piece of aluminum is 244 grams, what is the volume of the aluminum?

Chapter : Forces and their Effects

1. The diagram shows four forces acting on a plane in flight.

(a) Which arrow represents air resistance?Give the letter.

.............

(b) (i) When the plane is flying at a constant height, which two forces must be balanced?Give the letters.

............. and .............

(ii) When the plane is flying at a constant speed in the direction shown, which two forces must be balanced?Give the letters.

............. and .............

(c) (i) Just before take-off, the plane is speeding up along the ground.

Which statement is true?Tick the correct box.

Force B is zero.

Force B is greater than force D.

Force D is equal to force B.

Force D is greater than force B.

(ii) Which statement is true about the plane just as it leaves the ground?Tick the correct box.

Force C is zero.

Force C is greater than force A.

Force A is equal to force C.

Force A is greater than force C.

2. Anil sits on a mat at the top of a helter-skelter and then slides down a chute around the outside.

chute

A

B

mat

(a (i) Name two of the forces acting on Anil as he slides from point A to point B.

1. ....................................................................

2. ....................................................................

Chapter Solar System and Beyond

Q.1 Circle the correct answer:

1. The sun rise and sets everyday becauseA. The sun moves around the earthB. The earth moves around the sunC. The earth spins on its axis once every 12 hoursD. The earth spins on its axis once every 24 hours.

2.A satellite is A. Something that goes around the sunB. A planet that goes around a moonC. Something that goes around a planetD. Something that receives T.V programmes

3. The sun at midday A. Is highest in the springB. Is highest in summerC. Is highest in autumnD. Is highest in winter

4.The planet Mars has a longer year (687 Earth days).This is because (compared to earth)it:A. Revolves faster around the sunB. Is further away from the sunC. Is a much smaller planetD. Rotates faster on axis

5.Asteroids are A. Small lumps of rocks orbiting the earthB. Bigger than the earthC. Huge rocks revolving around starD. Small stars orbiting the sun

6. The pH of limewater isA. 1B. 7C. 11D. 3

7.Which of the following is NOT the general property of an alkaliA. Have a pH value more than 7B. Are good electrical conductors C. Have a bitter tasteD. React carbonates to produce carbondioxide

8.A piece of blue litmus paper remains blue in solution.We conclude that the solution is _________

A. AcidicB. AlkalineC. NeutralD. Not acidic

9.In hydroponics ,the _________of plants are immersed in solutions containing dissolved mineral salts

A. RootsB. StemsC. LeavesD. Seeds

10.When a large amount of solute dissolved in given amount of solvent then the solution isA. ConcentratedB. NeutralC. DiluteD. Super saturated

Q.2 a) List names of the planets according to their position from sun______________,____________________,__________________,____________________

_____________,_____________________,__________________,______________________

b)What is Equator?

____________________________________________________________________________________c)List the names of inner and outer planets and give reason why the planets are categorize in to inner and outer planets?____________________________________________________________________________________________________________________________________________________________________

Q.3a)What is neutralization?__________________________________________________________________________________

b))Complete the given equation:Acid +Alkali ______________,_____________Dilute nitric acid +Calcium carbonateDilute hydrochloric acid+ Sodium hydroxide solutionc)Complete the given table:

Substances pH

Car battery

13

Pure water

2

Limewater

d)Complete the given table:

Common name Chemical name

Caustic potash

Sodium hydroxide

Fizzy drinks

Lactic acid

Q3. When a solar eclipse happens, there is only a very small area on the Earth’s surface where you can see

the Sun completely blocked out. People in this area see a total eclipse. This area moves across the Earth as

the Earth spins round. If you are just outside this area you can see a partial eclipse, where the Sun is only

partly blocked out by the Moon.

This map shows where the Sun’s shadow was during the 1999 eclipse.

1 Look at the diagram. Where would you need to be on the Earth to see a total eclipse?

_________________________________________________________

2 The place where the shadow of the Moon falls on the Earth moves. Why does it move?

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

3 How long did the 1999 eclipse last altogether?

______________________________________________________________________________

4 Birds often go to sleep during a total eclipse. Why do you think they do this?

_______________________________________________________________________________

_______________________________________________________________________________

_____________________________________________________________________________