| A | B |
|---|
| active solar system | captures the sun's energy, then uses fans and pumps to distribute the heat |
| biomass fuels | fuels made from things that were once alive |
| control rods | cadmium rods used in a nuclear reactor to absorb neutrons from fission |
| efficiency | the percentage of energy that is actually used to perform work |
| energy conservation | the practice of reducing energy use |
| fossil fuel | nonrenewable energy resource formed by the decayed remains of ancient plants and other organisms in the Earth's crust; coal, oil, and natural gas are fossil fuels |
| fuel rods | uranium rod that undergoes fission in a nuclear reactor |
| gasohol | a mixture of gasoline and alcohol |
| geothermal energy | a type of energy that can be produced when heat from inside of the earth is used |
| hydrocarbons | energy-rich chemical compounds that contain hydrogen and carbon atoms |
| hydroelectric power | energy produced by flowing water |
| insulation | a type of material that tries to prevent the flow of thermal energy |
| meltdown | this occurs when the fuel rods in the vessel heat up so much that it starts to melt |
| nonrenewable resources | natural resources that are not replaced as they are used |
| nuclear fission | the splitting open of an atoms nucleus to form two or more new nuclei, releasing large amounts of energy |
| nuclear fusion | the joining of atomic nuclei, resulting in great energy release |
| nucleus | central core of the atom |
| passive solar system | converts sunlight into thermal energy without using pumps or fans |
| petrochemicals | compounds made from petroleum |
| petroleum | a liquid fossil fuel that is formed from tiny plants and animals that lived in the ocean long ago |
| reactor vessel | the section of a nuclear reactor where nuclear fission occurs |
| refinery | factory where crude oil is separated into fuels and other products |
| renewable resources | resources replaced by natural processes |
| reserves | known deposits of coal and other fossil fuels that can be obtained using current technology |
| solar energy | light and heat from the sun |
