Question

4. How does density affect refraction

Answer 1

"The density of a substance determines how much light is refracted"  

Hope this helps :)

Answer 2

Answer:

Density of any substance or medium determine the amount of light that will be refracted.

Explanation:

Density of any substance or medium determine the amount of light that will be refracted.

The higher is the density of any medium, the higher will be the number of atom or molecules in a given medium and hence more obstruction will be produced for light. High density also causes high refractive index.  

The light usually bends away from the normal when light travels from a region of low to high density and light bends towards the normal when light travels from a region of high to low density