Across
- 6. a buildup of heat at the earth's surface caused by energy from sunlight becoming trapped in the atmosphere
- 8. a pesticide or other material that is poisonous or harmful to an organism other than the target organism
- 9. colorless, odorless, and tasteless mixture of gases
- 11. colorless, odorless, and highly poisonous gas
- 16. material that is emitting radiation
- 17. pale-yellow element occurring widely in nature
- 19. heat and friction-resistant material
- 21. chemical used to control pests
Down
- 1. group of compounds consisting of chlorine, fluorine, carbon, and hydrogen used as aerosol propellants and refrigeration gas
- 2. process in which chlorophyll in green plants enables those plants to use light to manufacture sugar from carbon dioxide and water
- 3. colorless, poisonous, and oily liquid
- 4. a form of pollution consisting of small particles that are suspended in the air
- 5. any organism that adversely affects human activities
- 7. organic compound containing hydrogen and carbon
- 10. compounds containing nitrogen and oxygen
- 12. top layer of the earth's surface suitable for the growth of plant life
- 13. clear, colorless, tasteless, and nearly odorless liquid
- 14. colorless, radioactive gas formed by disintegration of radium
- 15. area or type of environment in which an organism or biological population normally lives
- 18. a process in which energy and carbon dioxide are released due to digestion or the breakdown of plant tissues during periods of darkness
- 20. compound that exists in limited quantities about 15 miles above earth's surface