Science Form 1 Chapter 1 Express Note
-
Upload
fikri-nafuri -
Category
Documents
-
view
94 -
download
0
description
Transcript of Science Form 1 Chapter 1 Express Note
CHAPTER 1Introduction to Science
EXPRESSEXPRESSEXpresS����������
1.1 What is Science?
1 Science is a systematic study of nature and its effects on us and the environment.
2 Natural phenomena are events that happen naturally around us.
3 Science can be divided into many fields such as: Biology, physics, chemistry, geology, astronomy and meteorology.
4 Science-based careers are occupations that are based on science, for example: Life science – doctor, nurse, dietician, botanist, zookeeper; earth science – environmental scientist, meteorologist, geologist, mineralogist, volcanologist; and physical science – physicist, chemist, engineer, architect, and radiologist.
1.2 A Science Laboratory
1 It is a room or a building where scientific investigations are carried out.
2 We must obey safety rules and precautions when working in a science laboratory.
3 Common laboratory apparatus:
Test-tube Boiling tube
Beaker Filter funnel
Bell jar Gas jar
Flat-bottomed flask Round-bottomed flask
Flat-bottomed flask Conical flask
Measuring cylinder
Water trough Tripod stand
Evaporating dish
Test tube rack
Test tube holder Crucible tongs
Dropper Eureka can
ExpressNotes SC (F1)1st 3 4/16/09 10:49:42 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 1
4 Hazard warning symbols:
Highly flammable
Examples:Ethanol, petrol
Explosive
Examples:Sodium, potassium
Corrosive
Examples:Concentrated hydrochloric acid, sodium hydroxide
Poisonous/toxic
Examples:Lead, mercury
Irritant
Examples:Chlorine, chloroform
Highly flammable
Examples:Ethanol, petrol
1.3 The Steps in a Scientific Investigation
(1) Identifying the problem
(2) Forming a hypothesis
(3) Planning the experiment
(4) Controlling variables
(5) Collecting data
(6) Analysing and interpreting data
(7) Drawing a conclusion
(8) Writing a report
1.4 Physical Quantities and Their Units
1 Physical quantities and their s1 units:
Physical quantities
SI unitsUnit
symbols
length metre m
mass kilogram kg
time second s
temperature kelvin K
electric current ampere A
1.5 Weight and Mass
1 The weight of an object is the pull of the Earth’s gravity on the object.
2 The mass of an object is the quantity of matter in the object.
1.6 Measuring Tools
Physical quantity
Tools/methodUnits
and their relationship
Length of straight lines
Metre rule, ruler, calipers (internal &
1 cm = 10 mm 1 m = 100 cm 1 km = 1000 m
external), micrometer, vernier calipers
Length of curves
String and ruler, opisometer
Area of regular shapes
Mathematical formulae, graph paper
1 cm2 = 100 mm2
1 m2 = 10 000 cm2
1 km2 = 1 000 000 m2
Area of irregular shapes
Estimation using graph paper
Volume of liquids
Measuring cylinder, pipette, burette
1 ml = 1 cm3
1 l = 1 000 cm3
1 m3 = 1 000 000 cm3
Volume of regular-shaped solids
Mathematical formulae, water displacement method (Eureka can or measuring cylinder filled with water) 1 m3
= 1 000 000 cm3
Volume of irregular-shaped solids
Water displacement method (using Eureka can or measuring cylinder filled with water)
ExpressNotes SC (F1)1st 4 4/16/09 10:49:43 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 2
1.7 The Importance of Standard Units
1 Standard unit improves international communications.
2 They also ensure the physical quantities are measured accurately and consistently.
CHAPTER 2Cell As a Unit of Life
2.1 What is a Cell?
1 A cell is the basic unit of life. 2 Its function is to carry out life processes.
Protoplasm Cell membrane
Nucleus Cytoplasm
Cell
Animal cells Plant cells
Irregular in shape Regular in shape
No cell wall Have cell wall
No chloroplasts Have chloroplasts
Mostly no vacuoles Have large vacuoles 3 The functions of cell structures:
Structure Function
Nucleus Controls all cell activities
Cytoplasm A place where chemical processes take place
Cell membrane Controls flow of materials in and out of cell
Cell wall Gives shape to the cell
(e)
(f)
2 A multicellular organism has many cells. (a) (b)
(c)
2.3 Cell Organisation in the Human Body
1 Organisation of cell:
Cell (simple)
↓
Tissue
↓
Organ
↓
System
↓
Organism (complex)
nucleus
Chloroplast Carries out photosynthesis
Vacuoles Stores water and dissolved materials
4 A microscope is used to study the general
structure of a cell.
2.2 Unicellular and Multicellular Organisms
1 A unicellular organism has one cell only.
(a)
(b)
(c)
(d)
Pleurococcus
Amoebapseudopodium
nucleus
Chlamydomonas
Paramecium
chloroplast
cilium
Euglena
Yeast
nucleus
bud
Chondrus Hydra
Spirogyra
ExpressNotes SC (F1)1st 5 4/16/09 10:49:46 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 3
2 Examples of cell: (a) Nerve cell
(b) Red blood cell
(c) Epithelial cell
(d) Bone cell
3 Examples of tissue: (a) Connective tissue
(b) Mucsle tissue
(c) Nerve tissue
(d) Epithelial tissue
4 Examples of system:
(a) (b)
(c) (d)
(e) (f)
BrainTongue
KidneyEye
StomachLungs
5 Examples of system:
2.4 The Human Being – A Complex Organism
1 A human being is a complex multicellular organism because the cells are organized into tissues, organs and systems.
2 Cell specialisation helps to divide body functions among the different types of cells.
3 Cell specialisation and cell organisation ensure the life processes are carried out effectively.
Pituitarygland
Testis(male)
Ovary(female)
Adrenalgland
Thyroidgland
Female
Oviduct orFallopian tube
OvaryUterus
Vagina
Male
Spermduct
Urethra
penis
Testis
Sex glands
Endocrine system
Nose
Trachea Bronchus
Lungs
Skin
Liver
Kidney
Urinarybladder
Respiratory system Excretory system
ExpressNotes SC (F1)1st 6 4/16/09 10:49:50 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 4
CHAPTER 3Matter
3.1 What is Matter?
1 Matter is everything that has mass and occupies space.
2 Examples of matter are wood, air, water, soil and living things.
3.2 The States of Matter
1 Matter exists in three states: solid, liquid and gas.
2 Matter changes its state when it is heated or cooled.
3 The kinetic theory of matter states that matter consists of tiny and discrete particles.
4 Characteristics of state matter:
Characteristic Solid Liquid Gas
Arrangement of particles
Closely packed
Further apart Very far apart
Spaces between particles
Very small Large Very large
Movement of particles
No free movement, vibrate about a fixed position
Move freely, collide with one another
Move freely, very rapidly and randomly
Density High Medium Low
Shape Definite shape
No definite shape
No definite shape
Volume Definite volume
Definite volume
No definite volume
Examples Soil, wood, most metals
Water, mercury (a type of metal)
Air
3.3 The Concept of Density
1 Density is defined as mass per unit volume of a substance.
MassDensity = ————
Volume
2 The unit of density is gram per cubic centimeter (g/cm3).
3 The buoyancy of a substance is affected by its density.
4 Buoyancy (or flotation) refers to the ability of a substance to float or sink in another substance.
5 A lower density substance will float on a higher density liquid.
6 On the other hand, a higher density substance will sink in a lower density liquid.
3.4 The Properties of Matter and Their Application in Everyday Life
Matter Example Applications
Solid Iron, steel To construct buildings, bridges and vehicles, make cooking utensils
Wood To build bridges ad houses, making furniture
Plastic To make toys, components in vehicles
Liquid Mercury To make thermometer, hydrometer
Water To make drinks, cooking, washing and cleaning
Gas Air To fill buoy, rise hot air balloons, make a submarine sink or float
CHAPTER 4The Variety of Resources on Earth
4.1 The Various Resources on Earth
1 The basic resources needed for life on Earth are:
Basic resource
ImportanceUseful
substances
Air Needed for respiration and combustion
Oxygen, nitrogen, carbon dioxide
Carbon dioxide is needed for photosynthesis
Water Needed to support the functions of the body systems
Fresh water
Soil Contains air, water, minerals and organic substances which are needed to support living things
Humus
Minerals Minerals such as metals are used to make useful products and construct buildings
Metals
water (1.00 g/cm3)
zinc (7.10 g/cm3)
cork (0.24 g/cm3)
ExpressNotes SC (F1)1st 7 4/16/09 10:49:53 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 5
Fossil fuels
Used to produce energy in power plants, factories, vehicles, machines and to make plastics
Coal, petroleum, natural gases
Living things
They are sources of food, building materials, clothes and fuel
Meat, skin, carcasses, silk, milk
4.2 Elements, Compounds and Mixtures
Comparing elements, compounds and mixtures
Aspect Element Compound Mixture
Appearance
Definition It is the simples substance
It is made up of two or more substances which are chemically combined
It is made up of two or more substances which are not chemically combined
Composition Only consists of one type of particle
Can consist of one or more than one type of particle
Separation method
Cannot be separated by any processes
Can be separated by chemical means only, such as electrolysis
Can be separated by physical means, such as filtration
Examples Iron, hydrogen, oxygen, helium, carbon, mercury
Naphthalene, sugar, rubber, table salt, water
Soil, air, dessert
Comparing metals and non-metals
Physical properties
Metals Non-metals
Surface appearance
Shiny Dull
Brittleness and hardness
Ductile (can be pulled into strands) and hard
Brittle (can break easily) and soft
Malleability (ability to be shaped)
Malleable Non-malleable
Conductivity of heat
Good conductor of heat
Poor conductor of heat
Conductivity of electricity
Good conductor of electricity
Poor conductor of electricity
Melting point High Low
Boiling point High Low
Density High Low Physical methods to separate components of a mixture
Physical properties
Metals Non-metals
Surface appearance
Shiny Dull
Brittleness and hardness
Ductile (can be pulled into strands) and hard
Brittle (can break easily) and soft
Malleability (ability to be shaped)
Malleable Non-malleable
Conductivity of heat
Good conductor of heat
Poor conductor of heat
Conductivity of electricity
Good conductor of electricity
Poor conductor of electricity
Melting point High Low
Boiling point High Low
Density High Low Comparing the Properties of Compounds and Mixtures
Aspect Compounds Mixtures
(a) Method of separation
By chemical reactions.
By physical means.
(b) Formation of a new substance
A new substance is formed
No new substance is formed
(c) Conversion of energy
Heat is released or absorbed when a compound is formed
No heat is released or absorbed when a mixture is formed
(d) Characteristic of the original components
The characteristics of the original components are no longer maintained
The characteristics of the original components are maintained
ExpressNotes SC (F1)1st 8 4/16/09 10:50:07 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 6
(e) Identification of the original components
The original components cannot be identified easily
The original components can be identified easily
(f) Ratio of components
Components are combined in a specific ratio
Components are formed without a fixed ratio
4.3 To Appreciate the Importance of Earth’s
Resources
1 Preservation of resources is the act of keeping the resources in their original state.
2 Conservation of resources is the responsible use and management of natural resources to prevent loss, waste or damage.
3 Preservation and conservation of Earth’s resources are important to:(a) prevent extinction of animal and plant
species(b) prevent depletion of natural resources
such as fossil fuels and minerals(c) prevent the pollution of air and water (d) ensure the basic needs of humans are not
threatened(e) ensure the natural resources will be
available for future generations
CHAPTER 5The Air Aroun Us
5.1 The Composition of Air
Nitrogen (78%) Oxygen (21%)
Inert gases + water vapour + dust + microorganisms (0.97%)
Carbon dioxide (0.03%)
Experiments to show the properties of air
1 Air consists of about 20% of oxygen.
Water fills up – of gas jar, showing that about 20% of the volume of air consists of oxygen
2 Air contains water vapour.
Beginning of experiment
End of experiment
Cork
Test tube
Ice
Water
Liquid on the outer wall of the test tube
3 Air contains microorganisms.
4 Air contains dust particles.
Glass slide
Sticky surface facing upDust particles
Glass slide
Dust particles
5.2 The Properties of Oxygen and Carbon Dioxide
Properties OxygenCarbon dioxide
Colour Colourless Colourless
Odour (smell) Odourless Odourless
Solubility in water
Slightly soluble
Slightly soluble
Solubility in sodium hydroxide
Not soluble Very soluble (to form sodium carbonate)
Effect on lime water
No effect Lime water turns cloudy
Supporting combustion
Supports combustion.
• A glowing splinter relights
• A burning splinter burns more brightly
Does not support combustion.• A glowing
splinter relights
• A burning splinter burns more brightly
pH Neutral• Has no
effect on moist blue and red litmus papers
• Has no effect on hydrogen carbonate indicator
Acidic• Turns
moist blue litmus paper to red
• Turns red hydrogen carbonate indicator to yellow
ExpressNotes SC (F1)1st 9 4/16/09 10:50:09 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 7
5.3 Oxygen is Needed for Respiration
1 Oxygen is needed for respiration to produce energy.
2 The composition of inhaled and exhaled air:
GasComposition (%)
Inhaled air Exhaled air
Nitrogen 78 78
Oxygen 21 16
Carbon dioxide
0.03 4
Inert gases 0.97 0.97
Water vapour
Less More
5.4 Oxygen is Needed for Combustion
1 Combustion is a process that requires oxygen, heat and fuel.
2 Combustion of carbon (such as charcoal):
Carbon + Oxygen → Carbon dioxide 3 Combustion of hydrocarbon (such as
kerosene):
Hydrocarbon + Oxygen → Carbon dioxide + Water
5.5 Air Pollution
1 Air pollution is caused by the pollutants in the air.
2 Air pollutants are harmful substances that are added to the air.
3 The effects of air pollution on human beings:• Lung cancers (caused by asbestos,
sulphur dioxide)• Brain damage in children (caused by lead
particles, carbon monoxide)
• Bronchitis, pneumonia (caused by sulphur dioxide)
• Death (caused by carbon monoxide) 4 The effects of air pollution on the
environment:• Acid rain (caused by sulphur dioxide)• Thinning of the ozone layer (caused by
CFC)• Greenhouse effect (caused by carbon
dioxide)• Haze (caused by dust particles, soot)
5.6 The Importance of Keeping the Air Clean
1 We can keep the air clean by practising the following:• Using less CFC based products, such as
aerosols.• Recycling and reducing wastes• Using unleaded petrol• Using public transport or sharing vehicles
(car pooling)• Installing catalytic converters to motor
vehicles 2 Cigarette smoke contains tar, nicotine and
carbon monoxide which are harmful to humans.
CHAPTER 6Sources of Energy
6.1 The Various Forms and Sources of Energy
1 Energy is an ability to do work.
2 The SI unit for energy is joule (J).
3 Forms of energy: Potential, electrical, kinetic, chemical, heat, nuclear, light, mechanical, sound
Energy Characteristics Examples
Potential (stored energy)
Energy stored in an object due to its position or condition.
• A stretched sling-shot
• A rock on a cliff
• A compressed spring
• A wound up alarm clock
Kinetic (working energy)
• Energy that is found in moving objects.
• A moving bus
• A swinging pendulum
• A rotating ceiling fan
• A flying aeroplane
Heat(working energy)
• Energy that is released by hot objects.
• A burning candle
• A boiling water
• The hot Sun• A hot iron
Light(working energy)
• Energy that is produced by glowing objects.
• A shining star
• A glowing light bulb
• A burning campfire
• A switched on torch
Sound (working energy)
• Energy that is produced by vibrating objects.
• A beating drum
• A person singing
• A blowing whistle
ExpressNotes SC (F1)1st 10 4/16/09 10:50:09 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 8
• A ringing telephone
Electrical(working energy)
• Energy that is produced by flowing electrical current (electricity).
• An electric iron
• An electric heater
Chemical(stored energy)
• Energy that is stored in a substance that can be burnt.
• Food• Fossil fuels
(such as natural gas, coal and petrol)
• Wood
Nuclear(stored energy)
• Energy that is produced by atoms that are broken down (through nuclear fission) or combined (through nuclear fusion).
• Explosion of an atomic bomb
• The explosion on the Sun’s surface
Mechanical(combination of working and stored energy)
• Energy that is posessed by an object that has both kinetic energy and potential energy.
• A car is driven up a hill
• A pendulum swings back and forth
4 Sources of energy:
Sources of energy
Examples Uses
Fossil fuels • Coal• Petroleum• Natural
gas
• To generate electricity in power plants
• As the main fuel for vehicles and machines
Wind • Moving air
• To move a sailboat
• To turn a windmill for pumping water and grind corn
• To generate electricity in wind farms
Water (hydro)
• Rain fall • To generate hydroelectricity
Sun (solar)
• The Sun • To generate electricity (solar cells and solar panels collect solar energy and convert it electrical energy)
• To enable photosynthesis in green plants.
Radioactive substances
• Uranium• Plutonium
• To produce nuclear energy.
• To produce electrical energy in submarines and warships
Geothermal • Geysers• Hot
springs• Volcanoes
• To produce geothermal energy that can be used to generate electricity
5 Energy changes from one form to another. For
example:
Situation Energy change
A marble rolls down a slope
Potential energy → Kinetic energy
Winding up spring of a toy car
Kinetic energy → Potential energy
Burning a candle Chemical energy →Heat + Light energy
Beating a drum Kinetic energy → Sound energy
Switching on a fan Electrical energy → kinetic energy
An exploding atomic bomb
Nuclear energy → Heat + Light + Sound energy
6 The Sun is the primary source of energy.
6.2 Renewable and Non-Renewable Energy Sources
1 Comparing renewable and non-renewable energy sources:
Renewable Energy (energy sources that can be reused and will never run out)
Non-renewable Energy(energy sources that will be used up one day and cannot be replaced)
• Solar energy (from the Sun)
• Fossil fuels (such as natural gas, petroleum and coal)
ExpressNotes SC (F1)1st 11 4/16/09 10:50:10 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 9
• Hydroelectricity (from flowing water)
• Biomass energy (from plants)
• Wind energy (from wind)
• Geothermal energy (from the Earth)
• Nuclear energy (from plutonium)
2 Conservation and efficient use of energy:
(a) Use energy efficient equipment, such as fluorescent lights
(b) Use public transport, such as buses and light-rail transit (LRT)
(c) Practice car-pooling to work
6.3 The Importance of Conserving Energy Sources
1 Conserving non-renewable resources will make them last longer for the future generations.
CHAPTER 7Heat
7.1 Heat as a Form of Energy
1 Heat is a form of energy 2 Heat can be produced from:
(a) kinetic energy, such as rubbing two objects together
(b) chemical energy, such as burning fossil fuels
(c) electrical energy, such as lighting an electric bulb
(d) nuclear energy, such as nuclear fission in the Sun
3 Comparing heat and temperature:
Aspect Heat Temperature
Definition on
A form of energy
Degree of hotness of an object
SI Unit joule (J) kelvin (K). Normally we use degrees Celsius (°C)
How it is produced
• Kinetic energy (such as rubbing hands)
• Chemical energy (such as burning fossil fuels)
• Electrical energy (such as lighting a light bulb)
• Nuclear energy (such as nuclear fission in the Sun)
• Supplying heat energy to an object (causing temperature to increase)
• Removing heat from an object (causing temperature to decrease)
Effect • Causes matter to expand or contract
• Causs matter to change from one state to another
• Causes matter to become hot or cold
• Causes heat to flow from a hot region to a cold region
Affected by • Volume- the bigger the volume, the more the heat
• Amount of heat- the more the heat energy is supplied, the higher the temperature
Difference
P contains more heat than Q
P and Q have the same temperature
7.2 The Effects of Heat Flow on Matter
1 Heat changes the volume of matter. 2 When heated, the volume of matter increases.
Hence, matter expands. 3 When cooled, the volume of matter decreases.
Hence, matter contracts. 4 Heat flows from a hot region to a cold region
in three ways: (a) conduction, occurs in solids (b) convection, occurs in fluids (such as
liquids and gases)(c) radiation, does not require a medium
7.3 Effects of Heat on Matter
ProcessChange of state
of matterHeat flow
Melting Solid → Liquid Heat is absorbed
Freezing Liquid → Solid Heat is released
P Q P Q
100°C100°C
ExpressNotes SC (F1)1st 12 4/16/09 10:50:11 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 10
Boiling Liquid → Gas Heat is absorbed
Condensation Gas → liquid Heat is released
Evaporation Liquid → Gas Heat is absorbed
Sublimation Solid → Gas
Gas → Solid Heat is absorbedHeat is released
7.4 Application of Contraction and Expansion of Matter
1 Application of expansion and contraction of matter:
(a) Mercury or alcohol in thermometers (b) Bimetallic strip in thermostats (c) Bimetallic strip in fire alarms (d) Gaps in railway tracks and bridges (e) Telephone wires (f) Metal pipes carrying hot water and oil
7.5 Absorbing and Giving Out Heat
1 Objects that absorb heat are called heat absorber.
2 Objects that give out heat are called heat radiator.
3 Dark, dull objects are good heat absorber and good heat radiator.
4 White, shiny surfaces are poor heat absorber and poor heat radiator.
7.6 The Benefits of Heat Flow
1 Application of heat flow via conduction:(a) Heat is used for cooking food with
cooking utencil(b) Heat is used to melt metal for making
jewellery and equipment2. Applications of heat flow via convection:
(a) Convection currents improve the air circulation and keeps the buildings cool
(b) Convection currents cool the Earth’s surface through sea breeze and land breeze.
3 Applications of heat flow via radiation:(a) Heat flow by radiation is used to dry
laundry(b) The heat from the Sun keeps the Earth
and our body warm
ExpressNotes SC (F1)1st 13 4/16/09 10:50:11 AM
mrc
heek
in.blo
gspo
t.com
.au
Page 11