Question

find the frequency of a photon whose energy is 4.135*10'5ev.

Answer 1

The energy of photon is connected with its frequency through the following formula:

$$E=h*\nu$$

where h is  Planck constant and v is the frequency of the photon.

Let's rewrite this formula:

$\nu=E/h$

$\nu=4.135*10^5*1.6*10^{-19}/6.6/10^{-34}=10^{20}$

Answer: v = 10²⁰ Hz