The frequency and wavelength of a wave are inversely proportional, meaning that as the frequency increases, the wavelength decreases, and vice versa.

The speed of light in a vacuum is approximately 2.99 (\times) 10^8 meters per second.

Refraction is the bending of light when it passes from one medium to another, such as from air to water or from glass to air.

The angle of incidence is the angle between the incident ray and the normal to the surface at the point of incidence.

The angle of reflection is the angle between the reflected ray and the normal to the surface at the point of incidence.

The angle of refraction is the angle between the refracted ray and the normal to the surface at the point of incidence.

The critical angle is the angle of incidence at which the refracted ray is parallel to the surface.

Diffraction is the phenomenon of the spreading out of light waves around the edges of an obstacle.

Interference is the phenomenon of the combination of two or more waves to form a new wave.

Refraction is the phenomenon of the bending of light towards a denser medium.

Reflection is the phenomenon of the bending of light away from a denser medium.

Total internal reflection is the phenomenon of the total internal reflection of light when it strikes a surface at an angle greater than the critical angle.

The formation of a rainbow is caused by the refraction and dispersion of light in water droplets.

The formation of a mirage is caused by the refraction of light in layers of air with different temperatures.

The formation of a halo around the sun or moon is caused by the diffraction of light by ice crystals in the atmosphere.