Prisms made of glass will light and create colored rainbows on a wall, as is shown in the image above

Disperse

Explanation:

A prism of glass disperses the light into its component of seven colors after refraction.

Refraction is a phenomenon of change of speed of light after there is change in the medium of the propagating light wave. The speed of light waves slow down after it passes through a relatively optically denser medium and vice versa.

When the light incidents on the surface of an optically denser medium at any angle other than 0 degrees to normal of the surface then it shows a deviation in its initial path and bends towards the normal in the denser medium and vice-versa.

The light on being refracted through a prism shows dispersion of light into 7 colors as shown in figure.

Red light having the highest wavelength among all visible colors and least bent, while the violet light has the smallest wavelength and maximum bend.