Question

A scientist observes light from a star with a wavelength 2 of 97 nanometers (9.7 x 10% mì What is the photon energy. E of this lightUse this information to help youvaispeed of light in a vacuum, c=3.00 x 10 meters/second• Planck's constant, h=4.136 x 10-15 ev s

Answer 1

Given data

The wavelength of the starlight is lambda 2 = 97 nanometers

The expression for the photon energy is given as:

`E=(hc)/(\lambda_2)`

Substitute the value in the above equation.

`\begin{gathered} E=\frac{4.136*10^(-15)\text{ eVs }*3*10^8\text{ m/s}}{97\text{ nm}}*\frac{1\text{ nm}}{10^(-9)\text{ m}} \\ E=12.79\text{ eV} \end{gathered}`

Thus, the photon energy is 12.79 eV.