What is the critical angle of a medium?

The angle of incidence is equal to the angle of:

The bending of light as it passes from one medium to another is called:

When a light ray enters into glass medium from water at an angle of incidence 0°, what would be the angle of refraction?

Light is made of seven colours. What is the method of separating the colours?

What is the unit of measurement for the intensity of light?