A-level Physics/Wave properties/Reflection and Refraction
Laws of reflection
Angle of Incidence = Angle of Reflection
The incident ray, reflected ray and the normal to the surface at the point of incidence all like in the same plane.
Refractive index
When light passes from one material to another the refractive index is the ratio of the speeds of light in the two materials.
Refractive Index = Speed in Air / Speed in Medium
Snell's Law
Snell's law is the simple formula used to calculate the refraction of light when travelling between two media of differing refractive index.