What is the frequency of an x-Ray with a wavelength of 1.15 times 10^-10

V = f 入 (velocity = frequency x wavelength)

If we have the speed (for wave in vacuum i. e. 3 x 10^8 m/s)

Then the frequency of x-ray is

(3 x 10^8) : (1.15 x 10^-10) = 2.61 x 10^18