Across
- 4. It vibrates back and forth and as it moves, it makes the air around it vibrate too. As the air moves away from the string, it carries energy out in all directions.
- 5. The regions of the wave where the air particles are closest together
- 6. A vibration or echo that you hear
- 7. Moving back and forth quickly
- 8. The regions of the wave where the air particles are farthest apart
- 9. Matter that waves can travel through
- 10. Sound must have a medium to travel through.
Down
- 1. The absence of matter
- 2. The measure of how high or low something sounds
- 3. The way waves travel