Identify the subshell corresponding to the lowest energy peak in the photoelectron spectrum (pes) of sulfur.

The answer that we want to get is the subshell that has the lowest energy. The farther the electron is from the nucleus, the lower is its energy. Thus, we should find the subshell at which the valence electrons are located. The electronic configuration for Sulfur is: [Ne]3s²3p⁴. Thus, the lowest energy subshell for sulfur is the 3p subshell.

Sulfur has 16 electrons. With 16 electrons you will have 3 shells with 2, 8 and 6 on each shell. Having 6 electrons on the last shell, it will have 2 subshells, the s subshell and p subshells with 2 and 4 electrons respectively. The lowest energy peak subshell for which the electron can be emitted is the p subshell of the third shell.