Question

Sound waves are compression or longitudinal waves that travel through matter. Sound travels through all three mediums, solids, liquids, and gases, at different speeds. Which statement BEST explains why sound travels fastest through solids and slowest through gases?
Responses
A It is easier for waves to pass through gases, then liquids, then solids.It is easier for waves to pass through gases, then liquids, then solids.
B Hard surfaces of solids cause sound waves to bounce off more quickly than in gases.Hard surfaces of solids cause sound waves to bounce off more quickly than in gases.
C Tightly-packed molecules of solids vibrate more quickly than loosely-packed gas molecules.Tightly-packed molecules of solids vibrate more quickly than loosely-packed gas molecules.
D Molecules in solids are spread apart while molecules in air are grouped together in clusters.Molecules in solids are spread apart while molecules in air are grouped together in clusters.
Question 2
Part B
If radio waves can travel through space, which answer choice does NOT correctly explain why we can't hear sounds in space as well?
Responses
A Sound waves are compression waves and require a medium.Sound waves are compression waves and require a medium.
B Sound waves are transmitted via particles called photons.Sound waves are transmitted via particles called photons.
C Radio waves are electromagnetic waves and do not require a medium.Radio waves are electromagnetic waves and do not require a medium.
D Because space is relatively empty, sound waves have no way to travel.Because space is relatively empty, sound waves have no way to travel.

Answer 1

Question 1: C
- Solids have tightly packed particles so mechanical vibrations (sound) transmit faster than in liquids or gases.

Question 2: B
- That statement is incorrect: sound is not transmitted by photons (photons carry electromagnetic waves). The real reason we can't hear in space is that sound needs a material medium (A, C, D are correct explanations).