Question

What is the electron configuration of oxygen and how many peaks does it have with the intensities of it ratio in the photoelectron spectra

Answer 1

O 1s²2s²2p⁴

About photoelectron spectra:

https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Map%3A_Physical_Chemistry_(McQuarrie_and_Simon)/10%3A_Bonding_in_Polyatomic_Molecules/10.04%3A_Photoelectron_Spectroscopy

https://onlinelibrary.wiley.com/doi/abs/10.1002/oms.1210260406