Across
- 4. The boundary between to unlike air masses
- 5. The bending of light as it passes one medium to another
- 8. Easily spread to other people
- 11. Any animal that hunts and eats other animals
- 12. usual weather of a region over a long period of time
- 13. Process where liquid changes to a gas
- 15. Protein inside the red blood cell
- 16. Last of the known member dies
- 17. The amount of matter in a certain space
Down
- 1. The distance from one compression to the next
- 2. Lose their leaves in the winter
- 3. Active at night
- 6. The nonliving part of the ecosystem
- 7. The scientific study of fossils
- 9. Small bits of weathered rock
- 10. Any substance that releases energy when it burns
- 14. Thin, wispy clouds