Speed of Light

[Nikita Patra 3J]

If light has different speeds depending on the medium it is in, does it change wavelength, frequency, or both?

[Michelle Shin 4B]

The wavelength changes, but the frequency remains constant in order to conserve energy.

[Frederick Keith_4C]

The speed of light can misleading because the value we use is light as observed in a vacuum (3.00 x 10^8 m/s), but the speed of light is not the same as it passes from medium to medium. When it enters a denser medium (from air to glass for example), the speed and wavelength of light decrease while frequency stays the same. All of this depends on the index of refraction, n, however.
Equation: n=c/v
Light slows down here because it runs into more particles and gets absorbed and then re-emitted within the denser medium.

[Cooper Baddley 1F]

The constant for speed of light as (3.00 x 10^8 m/s) refers to the fastest light can travel as it is measured in a vacuum but as stated before it can slow down when it goes through different thicker mediums.