What Is the Frequency $\nu$ In Hertz) of the Photons Emitted by a HeNe Laser

Multiple Choice

What is the frequency ( $\nu$ in hertz) of the photons emitted by a HeNe laser with a wavelength ( $\lambda$ ) of 632.8 nm?

A) 4.738 * 10⁵ Hz
B) 1.897 * 10² Hz
C) 1.897 * 10¹¹ Hz
D) 4.738 *10¹⁴ Hz
E) 1.897 *10¹⁴ Hz