1. Light
Refraction – the “bending” of light as it passes through a surface from one medium to another
When light leaves a less dense media such as air and enters a more dense media such as water, the light will bend towards the normal
When light leaves a more dense media such as water and enters a less dense media such as air the light will bend away from the normal

2. i – called the angle of incidence r – called the angle of refraction
Dotted line – Imaginary called the normal
Air – less dense than water i r
Water
The ray of light bends towards the normal
i – called the angle of incidence
r – called the angle of refraction
This happens for example when a straw is put into a glass of
water, it looks bent

3. i r

4. When the sine of the angle of incidence is divided by the sine of the angle of refraction it gives the refractive index, n. this is called Snell’s law.
Sin i =n
Sin r