Final answer:
Dispersion is the term for the spreading of different wavelengths of light, which occurs due to varying indices of refraction across these wavelengths.
Step-by-step explanation:
The spreading of different wavelengths of light due to slightly different indices of refraction is known as dispersion. This phenomenon occurs when white light is passed through a medium, like a prism, causing the light to spread into its composite colors—from red to violet—each bending at different angles. The index of refraction varies with wavelength; as the wavelength decreases, the index increases, with violet light having the highest index and therefore being bent the most. Dispersion is the term for the spreading of different wavelengths of light, which occurs due to varying indices of refraction across these wavelengths.