What is the frequency of green light, which has a wavelength of 4.90 x 10

Answer:
I found:
ν=6×10^14Hz
Explanation:
You can consider that wavelength λ and frequency ν are related through the speed of light in vacuum c as:
c = λ ⋅ ν
so:
3 * 10⁸ = 4.9 * 10-⁷ * V
v =3 *10⁸/ 4.9 *10⁻⁷ = 6 * 10¹⁴HZ