1. Sound travels fastest in:

2. In a longitudinal wave, particle vibration is:

3. The region in a sound wave where particles are pushed together is called:

4. The region in a sound wave where particles are less dense is called:

5. The region in a sound wave where particles are under high pressure is called:

6. The region in a sound wave where particles are under less pressure is called:

7. Sound cannot travel through a vacuum because:

8. Human hearing range is approximately:

9. Frequency is measured in:

10. Amplitude of a sound wave determines its: