Which property of light allows us to see a rainbow?

The property of light that allows us to see a rainbow is dispersion. Dispersion occurs when light passes through a medium, such as water droplets in the atmosphere, and splits into its constituent colors. This is because different colors of light have different wavelengths and refract at slightly different angles when they enter and exit the water droplets. As a result, when sunlight hits raindrops, it is refracted, reflected internally, and then refracted again as it exits the droplets.

The combination of these processes allows the light to separate into a spectrum of colors, creating the beautiful arc of a rainbow that we see in the sky. Understanding dispersion is crucial in grasping how rainbows form, as it highlights the role of both refraction and the properties of light in creating visual phenomena.