Suppose a new group 5A element is discovered. Photoelectron spectroscopy (PES) reveals that its last two peaks occur at 1370 kJ/mol and 777 kJ/mol. Calculate the average valence electron energy (AVEE) of this element.

The average valence electron energy (AVEE) of this element =

1014.2 KJ/ mol  or  1.0142mJ/mol.

Explanation:

The average valence electron energy =  (number of electrons in s subshell  x  Ionization energy of that subshell) + (number of electrons in p subshell  x  Ionization energy of that subshell) / total number of electrons in both subshells of the valence shells.

The 5A elements are non-metals like Nitrogen and Phosphorus with the metallic character increasing as you go down the group, So a new 5A element will have characteristics of its group with 5 valence electron in its outermost shell represented as ns2 np3

Therefore  the average valence electron energy (AVEE) of this element will be calculated as

The average valence electron energy = (2 x 1370  kJ/mol + 3 x 777 kJ/mol.) / 5

2740+2331/ 5 =5071/5

=1014.2 KJ/ mol  or  1.0142mJ/mol.