The wavelength of a light wave is 700 nm in air; this light appears red. If this wave enters a pool of water, its wavelength becomes λair/n = 530 nm. If you were swimming underwater, the light would still appear red. Given this, what property of a wave determines its color?

Answer

given,

wavelength of light in air = 700 nm

Wavelength of light in water = 530 nm

We know that speed of light changes when it moves from one medium to another.

And the frequency of the wavelength does not changes if the medium changes.

we also know that,

v = ν λ

From the above equation we can say that if frequency is constant so, with the change in velocity changes wavelength will also change.

Hence, wavelength is the property of the wave which determines color.