Across
- 1. A gas such as oxygen or nitrogen that was formerly thought to be impossible to liquefy.
- 7. the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.
- 10. variable gases are those present in small and variable amounts.
- 11. cattle produce it
- 12. you cant feel or see its changes
- 13. a mixture of nitrogen and oxygen
- 14. heats the atmosphere
- 15. layer of gasses that surround a planet.
Down
- 2. an abundant gas
- 3. oxygen that builds up in stratosphere
- 4. second most abundant gas
- 5. weight or measurement
- 6. doesn't react well with others
- 8. most abundant variable gas
- 9. traps thermal energy