What is the energy difference between the two quantum states involved in the transition of red light with wavelength 705 nm being absorbed by an atomic gas?

1 Answer
Jun 22, 2015

I found:
E=hν=2.82×1019J=1.76eV

Explanation:

A wavelength of 705nm corresponds to a frequency:
ν=cλ=3×1087.05×107=4.25×1014Hz

From Einstein's Relatonship you have that the photon energy will be:

E=hν=6.63×10344.25×1014=2.82×1019J=1.76eV

This is exactly the energy gap (or difference) between the two quantum states involved in the absorption of your photon of red light.