Energy
Energy — how things work
Say what energy does, name the sources a home and a vehicle run on, tell clean energy from fuels that pollute, and handle electricity safely.
Stand in a kitchen doorway and watch. Something is cooking, a fan is turning, a mixer is making a noise, the fridge is keeping things cold. Each of those is something happening — moving, lighting up, making a sound, doing work, changing temperature — and the thing that makes them happen is energy.
Where the energy comes from
You run about because of the food you ate. Animals move, fly, swim and hunt on the same supply. A vehicle runs on fuel instead, a stove burns cooking gas or wood or coal, and a plug supplies electricity. The Sun is the main source of energy for life on Earth, and the wind and flowing water carry it too.
Clean energy
Most of the electricity we use comes from burning coal, and burning coal makes a lot of smoke and harmful gases that pollute the air. Electricity made from natural sources — wind, water or the Sun — does not pollute the planet with smoke or waste, and that is what clean energy means. Solar panels capture sunlight; windmills spin with the wind; fast rivers and falling water turn wheels.
Electricity is useful and it is dangerous
Do not touch wires or the parts of a device while it is plugged in. Do not put your fingers, a pen or a stick into a socket. Keep clear of electric boxes and transformers. If you see a broken wire or a fallen electric pole, stay away and tell an adult straight away — and if something looks strange, do not try to fix it yourself.
Have a play
A house that draws on three natural sources of energy at once.
Tap any part of the picture.
Worked example
Two diyas are set out. One has a cotton wick and nothing else; the other has a wick with oil poured round it. Both are lit. What happens, and what does it tell you?
Watch the first diya. Its flame catches, burns down the dry wick and goes out quite soon.
The wick itself is the small amount of material there is to burn, so once it has burned there is nothing left.
Try it together
Work out why a village that puts up solar panels is doing something different from a village that burns more coal.
Both villages want the same thing: lights in the houses after dark.
1.The first village burns coal to make its electricity. Besides the electricity, what comes out of burning coal?
Have a go
Have a go on your own. You can still walk to school on a morning you skipped breakfast, and a torchlight works with nothing plugged into it. What word describes the energy your body and a battery are both holding for later?
Ready to practice?
Eight questions on what you have just read. Nothing is timed, and you can play as many times as you like.