Question

A quantum of electromagnetic radiation has an energy of 2.0 kev. what is its frequency? planck's constant is 6.63 × 10−34 j · s. answer in units of hz.

Answer 1

A quantum of electromagnetic radiation is called photon, and the energy of a photon is given by

`E=hf` (1)
where h is the Planck constant and f is the frequency of the photon.

In this problem, the photon energy is

`E=2.0 keV=2.0 \cdot 10^3 eV=3.2 \cdot 10^(-16) J`
If we re-arrange equation (1), we can find the energy of the photon:

`f= (E)/(h)= (3.2 \cdot 10^(-16) J)/(6.6 \cdot 10^(-34) Js)=4.8\cdot 10^(17) Hz`