| A | B |
|---|
| Joule | unit of energy |
| J | symbol for Joule |
| kJ | symbol for kilojoule |
| 1kJ = | 1000J |
| kilo means | 1000 |
| balanced diet | the right amount of the right types of food |
| nutrients | chemicals needed for good health |
| gram | unit of mass |
| g | symbol for grams |
| chemical energy | energy store in food, batteries and petrol |
| energy transfer | moving energy from a store |
| energy can be transferred by | heating, forces and sound |
| kinetic energy | movement energy |
| thermal energy | energy stored in hot objects |
| strain energy | when something is squashed, bent, stretched or twisted |
| gravitational potential energy | energy stored in a high object |
| elastic potential energy | another name for strain energy |
| nuclear energy | another name for atomic energy |
| energy transfer in nuclear power stations | nuclear energy |
| fuel | a substance that contains a store of nuclear or chemical energy |
| uranium | a nuclear fuel |
| examples of fossil fuels are | coal, oil, natural gas |
| fossil fuels are made from | the remains of dead animals and plants tat died millions of years ago |
| coal, oil and natural gas are | non-renewable |
| biofuels are | made from plants or animal waste |
| solar power uses | energy from the sun |
| solar panels consist of | tubes of water which heat up |
| solar cells use | energy transferred by light to produce electricity |
| electricity can be made in | solar power stations using solar energy and mirrors |
| moving water can be used to generate electricity | in a hydroelectric power station |
| waves and tides | can be used to generate electricity |
| geothermal power is generated by | pumping water through underground hot rocks |
| photosynthesis | the process by which plants make food using sunlight and CO2 |
| clouds form from | water evaporated by the heat of the sun |
| energy cannot | be created or destroyed |
| efficiency | how much of the energy transferred by a machine is useful |
| an efficient machine | does not waste much energy |
