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3. The nature of energy Energy can exist in different forms.
Look at the list of energy forms below and try to find examples of each.
Energy type
Thermal
Light
Sound
Elastic
Gravitational
Kinetic
Electrical
Chemical
Nuclear
Examples

4. Here are some answers: Energy type Examples
Thermal hot water, a hot radiator
Light light bulbs, Bunsen flame
Sound talking, TV, radio
Elastic a door closer, clockwork toys
Gravitational a book on a high shelf, a flying ball
Kinetic anything that is moving
Electrical anything electrical
Chemical food, batteries, burning things
Nuclear nuclear bombs, and power stations

5. The nature of energy Energy can be changed from one form to another.
Examples:
What other energy transfers can you think of?
Chemical energy in food is converted to thermal energy and kinetic energy by our bodies.
Gravitational energy in a ball is converted to kinetic energy when it falls to the ground.

6. In all these transfers, energy is conserved.
Suggest the energy transfer for the devices below:
chemical to heat and light
sound to electrical
electrical to sound and heat
electrical to sound and light and heat
elastic to kinetic and heat
chemical to sound and microwaves
(EM radiation) and heat
chemical to kinetic & sound & heat
A match burning
A portable torch
A microphone
A radio
A TV
A catapult
A mobile phone
A car
Click for answers
In all these transfers, energy is conserved.
Energy cannot be destroyed or created.

7. Energy resources
We all use chemical energy (food) to live and function. However, in a modern society we also use large amounts of energy from other sources.
Think of some activities requiring energy:
Traveling and communicating over long distances.
Controlling our environment - air conditioning / heating.
Manufacturing and building many kinds of materials and products – e.g. roads, cars, buildings, prepared food.
The pie diagram on the next slide shows where the energy comes from for some of these activities.

8. Energy supplies in Britain
These energy resources can be divided into two types:
renewable and non-renewable.

9. Non-renewable energy sources
Oil
Coal
Natural gas
Oil, coal and natural gas are examples of fossil fuels. They were formed from biological deposits over the course of millions of years.
There is a finite amount of these materials on the Earth so they will run out eventually.
Once they are used up they cannot be regenerated and used again.

10. Renewable energy sources
These will not run out because they can easily be regenerated.
Examples are wind power, solar power, tidal power and biomass.
Only 1% of the UK’s energy comes from these sources.
Can you think of a reason why?

11. Energy The Sun The original source of most energy resources.
Plants store the sun’s energy
through photosynthesis.
Animals then eat the plants.

13. The Sun Natural gas Oil The original source of most energy Coal
resources.
Coal
biomass
food
Wind
waves

14. How coal was formed
About 300 million years ago, plants photosynthesized and stored the Sun’s energy.
Coal
Dead plants fell into swampy water and the mud stopped them from rotting away.
Over the years, the mud piled up and squashed the plants.
After millions of years under this pressure, the mud became rock and the plants became coal.

15. Coal Formation

16. How oil was formed
Oil is also biological in origin. Millions of years ago tiny animals lived in the sea. Like now their ecosystem was dependent on heat and light from the Sun and photosynthesis by plants. When they died they fell into mud and sand at the bottom of the sea but didn’t rot away.
Over millions of years, they got buried deeper by the mud and sand. The temperature and pressure (caused by the weight of the sediments and deep burial) changed the mud and sand into rock and the dead animals into crude oil and natural gas.
This sample of crude oil was formed in Southern England. Crude oil formed in other parts of the world can be very different in appearance and viscosity.

17. Oil formation