1. energy The ability to make things happen. fuel Energy source; oil, natural gas, coal. source A force that gives rise to something. Thermal energy Heat energy.

2. Chemical energy Energy found in food and fuel Electrical energy Electricity, the energy that turns on light Bulbs and powers computers Nuclear energy Energy released when atoms are split apart and come together Radiant energy Energy sent out in the form of waves, such as light or heat energy

3. scalpel A tool: a small straight thin-bladed knife atoms A tiny particle