# How can you calculate ionization energy from wavelength?

Jun 24, 2016

I would say by using Einstein's Formula: $E = h f$

#### Explanation:

If you have the wavelength $\lambda$ of the photon needed to take an electron away from the atom you can use it into:
$E = h f$
where $h$ is Planck's Constant and $f$ the frequency.
Knowing that for the speed of light you have $c = \lambda f$
and so:
$E = h \frac{c}{\lambda}$