It is talking about the sun and the energy

1. 2.2 Energy from the Sun
Page No: 32, 33

2. Where does the energy stored in our
food come from?
 All the energy stored in food, like meat, vegetables
or fruit comes from the Sun.
 The diagram shows how sun is the source of energy
for all the plants that we harvest and eat.
 The diagram also shows how sun is the source of
energy for the chicken that we eat.
 Therefore either we eat plants directly or we eat
animals that ate plants.

3. Energy in fuels
 Trees use energy from the Sun to grow, when we burn these trees the stored
energy is released.
Definition: Biofuel - A biofuel is a fuel that we get from living things such as
plants or tree.
Examples of Biofuel:
Wood is an example of biofuel.
Alcohol is another biofuel that can be made from sugar cane which grown in
countries such as India and Indonesia.
Biogas can be made from the waste from animals and plants.

4. Energy in fuels
Definition: Fossil fuels - Fossil fuels are fuels that come from very old life forms that
decomposed over a long period of time. The three most important fossil fuels are
coal, oil, and natural gas.
Coal is formed from trees that were buried under mud millions of years ago.
Oil and gas are formed from sea creatures. They died and were buried under the sand
and mud at the bottom of the sea, for millions of years, under high pressure.
We can now drill down through the rocks and find these fuels. The oil that we find is
called crude oil, and it’s a mixture of many different useful fuels. In a refinery it is
separated into individual fuels, such as petrol (gas or gasoline) that is used in cars,
diesel, and jet fuel.

5. Wind and water
We can use the energy from the wind to
generate electricity.
The Sun heats up the land and oceans by
different amounts. This makes the air
move, forming the wind. The wind makes
wind turbines turn around. These drive
generators, which produce electricity.
Energy from the Sun also evaporates water
from the oceans. Water vapour is carried in
air and eventually falls again as rain. We
can trap the rain water behind dams to
make artificial lakes. When we release the
water we can generate electricity as it falls
downhill. This is called hydroelectricity.

6. How wind turbines work

7. Using the Sun’s energy directly
The energy from the Sun can be used to power solar cells.
These convert the Sun’s energy directly into electricity.
These are very useful and can be placed on small devices
like calculators.
Large number or solar cells can generate electricity for a
house or village.
In solar panels water suns through pipes and is heated using
the energy from the Sun. This reduces the amount of
biofuels or fossil fuels needed to heat water in cold
countries.

8. Assignment
1. Solve the 5 questions at the end of the textbook page 33.
2. Solve the workbook page number 18.