Question

Refraction occurs when light passing from one medium to another. True or False

Answer 1

Answer: True

Refraction is a phenomenon in which the light bends or changes its direction (and changes the speed of propagation, as well) when passing through a medium with a refractive index $n$ different from the other medium.  

Where the Refractive index is a number that describes how fast light propagates through a medium or material:

$n=\frac{c}{v}$

Being $n$ a relation between the speed of light in vacuum $c$  and its speed in the other medium $v$ .

It is important to note that in this process, the wavelength may be modified because it depends on the medium, however, the refracted ray of light does not change its frequency.