CHAPTER 4 : ENERGY

1. Energy enable living things and non-living things to carry out various types of process or work.

2. 

Sources of energy	Types or forms of energy produced
sun	light & heat energy
waterfall & dams	electrical energy
Oceans & seas
wind
battery
fuel	chemical & heat energy
food

•   Sound energy : radio,telephone, CD-player
•     Heat energy : fire, fuel, electric oven
•     Light energy : sunlight, candle light
•     Electrical energy :  battery, hydroelectric stations,generator
•     Chemical energy :fuel, coal, food
•     Kinetic energy : moving car, flying bird, bouncing ball

3. Energies can be transformed  from one form to another.For example, a burning candle transforms chemical energy into light energy and heat energy .

4. Renewable energy can be replenished when used up.(sun, wind, water, geothermal, biomass)

5. Renewable energy sources do not produce pollution.

6. Non-renewable energy cannot be replenished when used up.( natural gas, petroleum, charcoal, coal, nuclear reactor.

7. It is better to use and rely on renewable energy because :

•  renewable energy will always be available for our use as it will not be completely used up.
• the process of producing renewable energy does not normally cause environmental pollution.
• the production of renewable energy is normally cheaper in the long run.