Across
- 3. A natural fuel such as coal or gas, formed in the geological past from the remains of living organisms.
- 4. The emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization.
- 5. The production and discharge of something, especially gas or radiation.
- 7. A colorless, odorless gas produced by burning carbon and organic compounds and by respiration.
- 10. A glass building in which plants are grown that need protection from cold weather.
Down
- 1. The action of clearing a wide area of trees
- 2. The process of making an area more urban.
- 6. Radiant energy emitted by the sun
- 8. A nonrenewable energy source.
- 9. The mixture of gases surrounding the Earth or other celestial body, held in place by gravity