1
The law of conservation of energy
2
Fossil fuels
3
Geothermal energy
4
Hydroelectric energy
5
Potential energy
6
Electrical energy
7
Mechanical energy
8
Light energy
9
Kinetic energy
10
Nuclear energy
11
Chemical energy
12
Thermal energy
13
Sound energy
14
Wind energy
15
Solar energy
16
Natural gas
17
Renewable
18
Oil
19
Biofuels
20
Work
21
Energy
22
Source
23
Uranium
24
Coal
