title
Across
- 3. length of a wave
- 5. the highest point of a wave
- 6. solid, liquid, or gas
- 8. low density
- 9. the height of a wave
Down
- 1. a movement of energy
- 2. a unit of measurement for frequency
- 4. the lowest point of a wave
- 5. high density
- 7. how frequent waves appear