Across
- 4. metals use to protect another metal
- 6. harmful chemicals in the air, water or soil
- 9. also known as acid rain
- 10. earth's warming and cooling intervals
- 11. process that chemically degrades metal
- 12. process of adding limestone to acidic lake
- 13. applying zinc coating to iron or steel
- 14. an example of corrosion
Down
- 1. industrial device use to remove sulfur
- 2. natural acidic gas that causes acid rain
- 3. acidic materials deposited on earth
- 5. long-term trend toward warmer temperature
- 7. compounds that traps heat in atmosphere
- 8. acidic gas that causes acid rain