| Term | Definition |
| fossil fuel | the remains of ancient organisms that changed into coal, oil or natural gas |
| electric generator | a machine that converts mechanical energy, or motion, into electrical energy |
| petroleum | oil that is pumped from the ground |
| crude oil | another name for petroleum |
| oil reserves | oil deposits that can be extracted profitabley at current prices using current technology |
| nuclear energy | energy found in the nucleus of an atom |
| nuclear fission | collisions that cause the nucleus to split |
| nuclear fusion | occurs when light weight nuclei combine to form a heavier nucleus and release a large amount of energy |