Across
- 4. Lowest region of the atmosphere
- 6. Toxins in the air
- 7. underlain by the mantle
- 9. Variety of life in a habitat
- 13. Study of Human Interactions
- 17. Science of farming
- 19. relations of organisms
- 20. unstable toxic gas with a pungent odor and powerful oxidizing properties
Down
- 1. Availability of a resource and price of product
- 2. the layer of the earth's atmosphere above the troposphere
- 3. Step one in the water cycle
- 5. Rigid outer part of the earth
- 8. Fourth step in water cycle
- 10. Second step in Water cycle
- 11. the trapping of the sun's warmth in a planet's lower atmosphere
- 12. spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere.
- 14. Renewable
- 15. the process by which heat or electricity is directly transmitted
- 16. the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise
- 18. the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization.