Why is ionization energy of oxygen lower than nitrogen?

Moderators: Chem_Mod, Chem_Admin

Louise Zhuang
Posts: 31
Joined: Fri Sep 28, 2018 12:28 am

Why is ionization energy of oxygen lower than nitrogen?

Postby Louise Zhuang » Thu Nov 01, 2018 2:12 pm

According to periodic trend, I.E. increases from left to right, but O is lower than N

Matthew Choi 2H
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

Re: Why is ionization energy of oxygen lower than nitrogen?

Postby Matthew Choi 2H » Thu Nov 01, 2018 2:24 pm

Ionization energy is defined as the amount of energy required to remove an electron from a gaseous atom or ion. In order to answer this question, you need to look at the orbitals of both N and O. If you look at the 2p sublevel for N, there is one electron in each orbital. If you look at the 2p sublevel for O, there are two electrons in the first orbital and one in each of the other two orbitals. Since there are two electrons in the first orbital of the O sublevel, there is greater electronic repulsion in the 2p sublevel for O than N. Therefore, it is easier to remove an electron from the O than the N, and the ionization energy of O is lower than N.

Aaron Ang 4H
Posts: 30
Joined: Fri Sep 28, 2018 12:28 am

Re: Why is ionization energy of oxygen lower than nitrogen?

Postby Aaron Ang 4H » Thu Nov 01, 2018 2:27 pm

Nitrogen has a lower ionization energy than oxygen because nitrogen is half filled which according the Hund's rule, half filled and full filled orbitals are more stable.


Return to “Trends in The Periodic Table”

Who is online

Users browsing this forum: No registered users and 0 guests