Answer:
f = 1.5 x 10¹⁵ Hz
Step-by-step explanation:
Light is an electromagnetic wave and we know that the speed of light is a constant which is
3 x 10⁸ m/s.
Knowing this; v = λ x f
λ = wavelength
f= frequency of light
v = seed of light
f = v/λ
f = 3 x 10⁸m/s / 2.0 x 10-⁷ m
f = 1.5 x 10¹⁵ Hz