| A | B |
|---|
| energy from the sun | solar energy |
| brown coal; second stage of coal. | lignite |
| process in which hydrocarbons in fossil fuels are combined with oxygen at high temperatures, releasing heat energy and light energy; burning. | combustion |
| soft substance made of decayed plant fibers; first stage of coal. | peat |
| device that absorbs energy from the sun and converts it to heat; part of an active solar-heating system. | solar collector |
| any useful substance derived from oil or natural gas. | petrochemical |
| device that converts sunlight directly into electricity; solar cell. | photovoltaic cell |
| soft coal; third stage of coal. | bituminous coal |
| fuel formed hundreds of millions of years ago from the remains of dead plants and animals; coal , oil or natural gas. | fossil fuel |
| hard coal; fourth and last stage of coal. | anthracite |
| substance containing the elements hydrogen and carbon. | hydrocarbon |
