AP CHEM Experiments

** Photoelectron Spectroscopy** Photoelectron spectroscopy is a technique that measures the kinetic energy of electrons emitted from a material when it is irradiated with ultraviolet or X-ray radiation.

How it works

1. Irradiation: A sample is irradiated with photons (UV or X-rays) with known energy.
2. Photoionization: The photons interact with electrons in the sample, causing them to be ejected (photoionization).
3. Energy Analysis: The kinetic energy of the emitted electrons is measured using an electron energy analyzer.

Photoelectron spectroscopy provides information about the electronic structure of the material, including:

• Element Identification: By identifying the core-level binding energies of electrons, it can determine the elemental composition of the sample.

How to read a PES Graph

• A filled S/P/D/F shell will emit the same amount of energy every time
  • The peak will go up the same height
• If it is not filled, it will only go up part-way
• This one, for example, shows 3 full S shell peaks, meaning it is a $$ 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 $$ -