The Photoelectron Spectroscopy (PES) spectrum of oxygen (O) reveals information about the energy levels of its electrons. Based on the provided reference, the idealised PES spectrum for oxygen has three distinct peaks, each corresponding to the different subshells from which electrons are being ejected.
Understanding Oxygen's PES
The ground-state electron configuration of oxygen is 1s22s22p4. This configuration means oxygen has:
- 2 electrons in the 1s subshell
- 2 electrons in the 2s subshell
- 4 electrons in the 2p subshell
Peaks in the PES Spectrum
Each peak in the PES spectrum corresponds to the energy required to remove an electron from a specific subshell. The three peaks observed are due to the electrons in:
- 1s subshell
- 2s subshell
- 2p subshell
The order of peaks from lowest to highest binding energy will be 2p, 2s, and then 1s.
Key Insights from the PES of Oxygen:
- Subshell Energies: The spectrum directly shows the relative energies of the different subshells within the oxygen atom.
- Electron Configuration Confirmation: The number of peaks and their relative intensities (which are not mentioned in the provided reference but are related to the number of electrons in the subshell) help to confirm the electron configuration of the oxygen atom.
Summary of Oxygen's PES
In summary, the PES of oxygen shows three peaks, each indicating the energy required to remove an electron from the 1s, 2s, and 2p subshells, providing direct evidence of the electronic structure of oxygen.
