| A | B |
|---|
| acid precipiation | rain, sleet, or snow that contains a high concentration of acids |
| biomass | organic matter that can be a source of energy; the total mass of the organisms in a given area |
| chemical energy | the energy released when a chemical compound reacts to produce new compounds |
| coal | a fossil fuel that forms underground from partially decomposed plant material |
| gasohol | a mixture of gasoline and alcohol that is used as a fuel |
| geothermal energy | the energy produced by heat within the Earth |
| hydroelectric energy | electrical energy produced by falling water |
| natural gas | a mixture of gaseous hydrocarbons located under the surface of the Earth, often near petroleum deposits; used as a fuel |
| natural resource | any natural material that is used by humans, such as water, petroleum, minerals, forests, and animals |
| nonrenewable resource | a resource that forms at a rate that is much slower than the rate at which it is consumed |
| nuclear energy | the energy released by a fission or fusion reaction; the binding energy of the atomic nucleus |
| nuclear fission | the process in which the nuclei of radioactive atoms are split into two or more smaller nuclei; releasing energy |
| nuclear fusion | the combination of the nuclei of small atoms to form a larger nucleus; releases energy |
| petroleum | a liquid mixture of complex hydrocarbon compounds; used widely as a fuel source |
| recycling | the process of recovering valuable or useful materials from waste or scrap; the process of reusing some items |
| renewable resource | a natural resource that can be replaced at the same rate at which the resource is consumed |
| smog | photochemical haze that forms when sunlight acts on industrial pollutants and burning fuel |
| solar energy | the energy received by the Earth from the sun in the form of radiation |
| wind power | the use of a windmill to drive an electric generator |
