1.5 Photoelectron Spectroscopy

Photelectron Spectroscopy

Photoelectron spectroscopy is a technique used to measure the energies of electrons in an atom. On the AP, you will need to interpret photoelectron spectroscopy graphs.

The closer an electron is to the nucleus, the higher the binding energy. The peaks correspond to a subshell. The first peak is ${1s^2}$, the second is ${2s^2}$, etc. The peak on the left has the highest binding energy, which means they are ${1s^2}$, since they are closest to the nucleus, and the next two are ${2s^2}$. The last peak only has 4 electrons, so it is ${2p^4}$. The element with an electron configuration of ${1s^2}$ ${2s^2}$ ${2p^4}$ is oxygen.