Question

An argon-ion laser emits a blue-green beam of light with a wavelength of 488nm in a vacuum. Compute the energy in joules for the two energy states for the atomic transition which produces this light?

Answer 1

$$E=\frac{hc}{\lambda}$$

$$E=\frac{1.99\cdot10^{-25}}{488\cdot10^{-9}}=4.08\cdot10^{-19}\ J$$