Energy

6. The average kinetic energy of the particles in a substance, measured in degrees Celsius (°C).
8. The amount of matter in an object, measured in kilograms (kg).
10. The unit of energy.
11. An object or group of objects.
12. The energy stored in chemical bonds.
15. A material that does not allow energy to transfer through it easily.
16. Useful energy transferred by a device divided by the total energy supplied to the device, or useful power output divided by total power input.
17. A substance used in nuclear reactors to transfer energy through fission.
18. A finite energy resource formed over millions of years from the remains of dead plants and animals. Examples are coal, oil and natural gas.
19. The mass per unit volume of a substance, measured in kilograms per metre cubed (kg/m3). It is calculated by dividing the mass of an object by its volume.

1. A way in which energy can be kept in a system (enabling the calculation of the ability of a system to do work).
2. The transfer of energy from one energy store to another.
3. The unit of power
4. The amount of energy required to raise the temperature of one kilogram of a substance by one degree Celsius, measured in joules per kilogram per degree Celsius (J/kg °C).
5. A measure of the stiffness of a spring, measured in newtons per metre (N/m).
7. The energy store of a moving object.
9. A liquid or a gas
13. Useful energy transferred by a device divided by the total energy supplied to the device, or useful power output divided by total power input.
14. Something with a high energy density.
20. The capacity of a physical system to perform work.