TRUE OR FALSE Total internal reflection occurs when light moves from an area of higher index of refraction to one of lower index and strikes the boundary at an angle greater than the critical angle.

The answer is true.

Iwould think it is temperature, silica, oxides (gases)

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.