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1. CONTENTSTANDARD:
The Learners should be able to…
Apply knowledge of the sources and
uses of light, sound, heat and electricity
TOPIC: LIGHT,
SOUND,HEAT &
ELECTICITY

2. PERFORMANCE STANDARD:
The Learners should be able to…
Describe sources of light, sound,
heat and electricity.

3. Most Essential Learning
Competencies
Describe the different uses of light, sound,
heat & electricity in everyday life.

4. SOURCES OF LIGHT,
SOUND, HEAT &
ELECTRICITY

5. OVERVIEW
Light is a form of energy that
enables us to see all the things
around us.

6. OVERVIEW
Sound is another form of energy
produced by a vibrating body.

7. OVERVIEW
Heat is a form of energy. Heat
flows from hot objects to cool objects.

8. OVERVIEW
Electricity is a form of energy like
light, heat, and sound. Electricity works
only when an electric current flows
through a closed or complete circuit.

9. LIGHT

10. Light helps us see the beauty of
God’s creation…
Plants
Animals
Human

11. SOURCES OF LIGHT
Natural Sources of Light
These sources come to Earth through
natural means which man cannot
control.
Artificial Sources of Light
Artificial light comes from sources that
man produces and controls.

12. NATURAL SOURCES OF
LIGHT

13. SUN
The sun is a natural source of light. It is also the
primary source of light. Earth gets light from the
sun.

14. MOON
The moonlight we see at night is sunlight reflected
from the surface of the moon

15. STARS
The stars also light up the sky at night. Some stars
provide a very small amount of light because they
are very far from us.

16. OTHER NATURAL SOURCES OF LIGHT
 bioluminescence

17. OTHER NATURAL SOURCES OF LIGHT
 bioluminescence

18. ARTIFICIAL SOURCES OF LIGHT

19. USES OF LIGHT
 You see the world around you. Light helps you play
and work.
 You can see the colors of the traffic lights to guide
you when to stop, slow down, or go.
 You can read newspapers, books, and even email
messages.

20. USES OF LIGHT
 You can read newspapers, books, and even email
messages.
 You can watch television programs and movies, and
play video games.
 You can take pictures of your friends using a camera.

21. Proper and Safe Use of Light at Home
 Protect your eyes from too much light.
 If you are reading, use enough light.
 Avoid looking directly at the sun or at any
bright source of light.

22. Proper and Safe Use of Light at Home
 Inside the house, let the sunlight
in.
 Switch off any artificial light when nobody is using it.
 Do not put a lighted candle or alcohol or gas lamp
near combustible objects.
 Do not leave a lit candle or gas lamp unattended.

23. KEY CONCEPTS
 Light comes from the sun. It is the
primary source of heat and light.
 Light comes from different sources natural
sources and artificial sources.

24. HEAT SOURCES!
What’s a heat source? What isn’t?

26. HEAT SOURCE!
A heat source is something that
makes it’s own heat!

27. FOR EXAMPLE…
An ELECTRIC HEATER is a heat source! It makes heat and can warm up a room!
A pair of socks is NOT a heat source.
Though socks can help keep your feet
warm, they don’t make their own heat.
They simply use INSULATION to keep your
feet warm.

28. Fire
IS IT A HEAT SOURCE?

29. Fire

30. A Blanket
IS IT A HEAT SOURCE?

31. A Blanket

32. A Computer
IS IT A HEAT SOURCE?

33. Computer

34. A Coat
IS IT A HEAT SOURCE?

35. A Coat

36. A 3rd Grader
IS IT A HEAT SOURCE?

37. 3rd Grader

38. Carpet
IS IT A HEAT SOURCE?

39. Carpet

40. The Sun
IS IT A HEAT SOURCE?

41. Sun

42. Asphalt
IS IT A HEAT SOURCE?

43. Asphalt

44. The metal part of a
Seat Belt
IS IT A HEAT SOURCE?

45. The metal part of a
Seat Belt

46. Lights
IS IT A HEAT SOURCE?

47. Lights

48. The Stove
IS IT A HEAT SOURCE?

49. Stove

50. Clouds
IS IT A HEAT SOURCE?

51. Clouds

52. WHAT ARE SOME EXAMPLES OF HEAT
SOURCES YOU CAN THINK OF?

53. What are some examples of
things that are NOT heat
sources?

54. Heat Source Not a Heat Source
Fire Blanket
Computer Coat
A 3rd Grader Carpet
The sun The Asphalt
Lights A Seat Belt
A Stove Clouds

55. Heat

56. •Heat as a form of energy . Heat
can make things hot and we can
use heat to do work.
•We feel hot when the Sun
shines. This shows that the Sun is
a source of heat energy and gives
out heat. Most of the heat on the
Earth comes from the Sun.

57. •Apart from the Sun, there are many other sources
of heat. Heat can be produced in many ways.
•Here are some activities to show possible heat
sources.

58. Heat sources Activities
•Rubbing or friction-
rubbing two objects against
each other can produce
heat.
•Rub your hands together
for some time and then
hold them to your cheeks.
Your cheeks will feel warm,
showing that heat can be
produced by friction.
Rubbing hands can produce heat

59. •Burning- when an
object burns, it
produce a flame that
gives out heat.
•Burn a candle or a piece of
paper and put your hands above
it. Your hands will feel hot,
showing that burning substances
can produce heat.
Burning substances can produce heat

60. •Electricity – when
electric current flows
through a wire, heat is
produced.
•Switch on the electric bulb for
some time and place your hands
near the bulb. Your hands can
feel the heat coming out from
the bulb.
Electricity can produce heat

61. •Heat can also be produced by:
a. Bending metal- bending a coat hanger or a
wire back and forth several times can
produce heat in the object.
b. Chemical reaction – after mixing solid
sodium hydroxide with water in a test tube,
the test tube will get warm.
c. Collision – when an iron nail is hit by a
hammer several times, the hammer and the
nail will get hot.

63. •Heat is a useful form of energy. We use heat to:
a. Cooking food
b. Drying clothes
c. Boiling water
d. Producing steam to generate electricity
e. Food drying for reservation
f. Providing warmth

64. •Heat is a form of energy. An object becomes hot when it
absorbs heat. Heat is measured in Joules (J).
•Temperature measures how hot or cold an object is. The
unit of temperature is degree Celsius ( C) or Kelvin (K).
Temperature can be measured with a thermometer.
•Heat and temperature are different.
•The table below shows the differences between heat
and temperature.

65. Heat Temperature
• A form of energy •The degree of hotness or
coldness of a body
•Heat can do work •Temperature cannot do work
•Measured in Joule (J) •Measured in degree Celsius (C)
or Kelvin (K)
•Transfer from a hot area to a
cold area.
Increases when heated and
decreases when cooled

66. •Objects with the same
temperature contain the
same amount of heat.
The higher the
temperature of an
object, the larger the
amount of heat
contained in it.
•The amount of heat
contained in an object
depends on
a. The type of the
material that the
object is made of.
b. The mass or the size
of the objects, and
c. The temperature of
the object.

67. •Heat only travels from a hotter object (or place)
to a cooler object (or place)
•Heat has several interesting ways of travelling:
It travel by three ways:
a. By conduction through solids
b. By convection through liquids or gases
c. By radiation through vacuum

68. •The flow of heat energy through solids such as metals
is called conduction.
•Heat energy uses molecules to help it to get around.
•For example, when a pan is heated, the molecules at
the bottom of the pan start to vibrate energetically.
They collide with their neighboring molecules and
cause them to vibrate faster. The passing of the heat
energy from one molecule to the next continues. In this
way, heat energy travels through the pan and then
through the food in the pan.

69. •Heat can flow through a liquid or a gas because
heated parts of the liquid gas move.
•Warm air rising above a heater is an example.
•The flow of heat that occurs when a warm liquid
or gas moves is known as convection.

70. •The process where heat energy travels through an
empty space or a vacuum is known as radiation.
•An example of radiation is the transfer of heat from
the Sun to the Earth through mostly empty space.
Such a transfer cannot occur via convection or
conduction, which requires the movement of material
from one place to another, or the collisions of
molecules within a material.

71. •Some natural phenomena occur as a result of
heat flow.
•Warming of the earth by the Sun
a. The Sun gives solar energy every day. During
the day, the Earth’s surface is warmed up
and during the night, this energy is radiated
back into space as radiant heat energy.

72. b. A fraction of the solar energy that reaches the
Earth is absorbed, causing evaporation of water
from the oceans, the lakes, the lands and plants.
Convection current carries the water vapour up
to the atmosphere to form clouds, which will
form rains and thunderstorms
c. The warming of the Earth by the Sun can cause
changes in the climatic conditions of the Earth
and many natural phenomena such as land ad
sea breezes, thunderstorms, hurricanes and so
on.

73. a. The unequal heating or air over land and water
will result in breezes near the shores.
b. During the day, both land and sea are heated by
the Sun. However, the land gets heated up
faster than the sea. The air above the land
surface heats up, expands and rises. It is lighter
than the surroundings air. To replace the rising
air, cooler air is drawn in from the surface of the
sea. This is the sea breeze. It can offer a
pleasant cooling effect on a hot afternoon.

75. c. At night, the land cools faster than the sea. When
this happens, the air over the warmer surface of sea
heats up and rises, pulling in air from the cooler land
surface to replace it. This is the Land breeze.

76. •A building can be kept cool by having a good
ventilation system, so that air circulation in the
building is ongoing. Hot air from the building flows out
from the top and cool air can flow in from the bottom.
•Most of the traditional houses are built with
ventilation holes at the base of the house and at the
top near the roof. Hot air inside the house will rise and
flow out through the ventilation holes at the roof. Cool
air will enter through the openings at the base of the
house to replace the hot air. This produces a natural
convection current inside the house.

77. •In modern buildings, the ventilation system is made
more effective by installing exhaust fans and extractor
fans. Hot and humid air can be sucked out and replaced
with fresh and cool air.
•Modern houses are equipped with fans and air
conditioners to make the house cooler. Modern
buildings use centralized air conditioning system to cool
the whole buildings.
•Insulation can also help to keep a building cool.
Buildings with loft insulation, insulating cavity walls or
double gazed windows are usually much cooler than
those which are built without insulating materials.

78. •When material allow heat to pass through them
rapidly, they are known as conductors. All metals are
good conductors of heat compared with other
materials.
•Other materials like- metals, liquids and gases that do
not allow heat to pass through easily are known as
bad conductors of heat or insulators.

79. Conductors Insulators
Mercury (liquid) Glass
Silver Air
Copper Water (liquid)
Aluminum Plastics
Zinc Rubber
Iron Wood
Lead Materials containing trapped air
( wool, plastic foam, expanded
polystyrene)

80. Materials/ devises Uses
Cooking utensils
Insert image
kettle
•Cooking utensils such as
saucepans, pots and kettles are
usually made of aluminum or
stainless steel.
•They conduct heat quickly and
easily to the food as thus save
fuels.
Examples of the uses of heat conductors in
daily life.

81. Electrical appliances
Insert image
iron
•Electrical irons and hot plates
are made of iron or stainless
steel that conducts heat well.
•Heat sinks that are used in
computers, disk drives and
televisions as cooling fins are
made of aluminum
Others
Insert image
Soldering iron rods
•Radiator coils and cooling fins
behind the refrigerator are made of
copper.
•Soldering iron rods are made of
iron with copper tips.

82. Materials/ devices Uses
Wood or plastics •Handles for cooking utensils, kettles,
teapots, soldering iron rods and so on.
•They protect our hands from the hot
surfaces.
Cork, asbestos sheets, tiles To prevent tabletops from being
damages by hot kitchenware or
objects.
Sawdust To cover ice blocks to slow down the
melting process.
Insulators are used in many applications where
we want to minimize heat flow or heat loss.

83. Woolen blanket or cloth •Used to keep the body warm on cold
days. The woolen blanket and the air
layer trapped inside can prevent heat
loss from the body.
Fiberglass, expanded
polystyrene foam
•Used as insulators in the walls of ice
boxes and refrigerators. Air trapped
inside acts as insulator.
insulating cavity wall,
double- glazed glass
Used in the buildings to prevent heat
from entering by conduction during
Aluminum Plastics the day and prevent heat loss at
night.

84. There are many uses of heat flow in
our daily life:
a. The flow of heat through
conduction is used for cooking
and boiling. Conduction of heat
is also applied in electric irons,
ovens and toasters.
b. The flow of heat by convection
and radiation is used to dry wet
clothes, salted fish and others. Drying wet
clothes

85. c. Heat flow through radiation gives us hot water when
we use a solar heater to absorb heat from the Sun.
d. Convection currents can help to improve air
circulation and cool our houses and buildings. Fans and
air conditioners help to cool the surrounding air
through convection currents
Air conditioner.

86. e. Our life can be made healthier and more
comfortable with a good ventilation system in our
houses. Windows, opening and exhaust fans are things
that can help to improve the ventilation of air in a
house. Warm air inside the house can be drawn out
and replaced with fresh, cool air from the outside.

87. Ventilation of buildings

88. www.drecart.com
Electrical Energy

89. • All matter is made up of atoms.
• Centre of each atom is a heavy nucleus.
• Surrounding the nucleus is a lot of empty space and
tiny particles called electrons (which are constantly
moving).
• Each electron carries a negative electric charge.
Oxygen Atom

90. • Inside the nucleus are two different particles –
protons and neutrons.
• Protons are much heavier than electrons and they
carry a positive electric charge.
• Neutrons have a similar mass to protons but carry
no electric charge.

91. The positive electric charge of a proton exactly
balances the negative charge of an electron. Atoms
contain an equal number of electrons and protons.

92. • Any particle or substance that has more protons
than electrons is said to be positively charged.
• More electrons than protons is said to be
negatively charged.
• Equal amounts of positive and negative charge is
said to be neutral.
Helium Atom

93. STATIC ELECTRICITY
• Is the build up of electric charge on a surface.
• Commonly occurs because of two surfaces
rubbing against each other.
homeschooljabber.blogspot.com

94. The electrons are rubbed off one surface – charging
is positive – and are transferred to the other surface
– charging it negative.
www.aapt.org

95. CURRENT ELECTRICITY
• Power from batteries and power points is made up
of electrons moving along a wire – electric current.
• The energy from the moving electrons is
transformed into other forms of energy such as
heat and movement.
www.nmsea.org

96. MEASURING ELECTRICITY
• Electric Current – when charge flows (measured using a ammeter).
• Unit used to measure current is ampere/amps (A).
• Voltage – measure of the amount of energy supplied and used by the
charges.
• Unit used to measure voltage is volts (V).
wps.pearsoned.ca

97. • Supply Voltage – Australia 240V
• Some household items use transformers.
• A step-down transformer reduces 240V to the amount
required by an appliance.

98. BATTERIES
• Portable electrical energy.
• Wet Cell – two electrodes placed in a liquid electrolyte i.e.
conducts electricity.
• Dry Cell – used in torches, toys etc. don’t leak because
they use paste instead of liquid.
• Photovoltaic Cells – solar cell.

99. • Resistance – when electrons pass along wires
their path is restricted by the atoms that make up
the wires.
• A measure of how difficult it is for an electric
current to flow.
https://learn.sparkfun.com/tutorials/resistors

100. CONDUCTORS AND INSULATORS
• Conductors - materials with little resistance
to the flow of electric charge (e.g. copper
wires used in most electric circuits).
• Little energy is needed for electric charge to
flow through conductors.
• Most metals are very good conductors of
electricity.

101. • Insulators - materials with a lot of resistance to the flow of electric charge
• Allow very little or no electric current through e.g. air, rubber and plastic.

102. CIRCUIT DIAGRAMS
Circuit diagrams are universal so they can be used all over the world.

103. SERIES CIRCUIT
• A string of Christmas tree lights are all connected to the same power supply.
• If you remove a single light the rest of the lights will go off.
• This is because the lights are connected in series.

104. PARALLEL CIRCUIT
The ceiling lights in most homes need to be connected together so that if one light globe or tube
stops working, the others remain on – this requires a parallel circuit.