Why does Oxygen have a lower first ionization energy then nitrogen?

Why doesnt Fluorine have lower ionization energy than Oxygen?

• Oxygen has one filled p orbitals that contains two electrons.These two electrons repeal each other,thus lowering the ionization energy of Oxygen relative to Nitrogen. But Fluorine has two filled p orbitals, will not these electrons repeal each other more than electrons in the p orbital in Oxygen, thus lower the ionization energy of Fluorine relative to Nitrogen. Which means lower ionization energy than Oxygen.

• Answer:

  I don't know why you were so specific about F; it's not even an exception (something that inorganic chemistry is filled with). Ionization increases from left to right and from bottom to top across the periodic table. The reason is elements on the right have more protons pulling on the electrons than the ones on the left. Therefore you need more energy to break this "pull" from more electrons. "These two electrons repeal each other,thus lowering the ionization energy of Oxygen" 'lowering the ionization energy of Oxygen' relative to what? It is not relative to other elements, but relative to what it might have been had the orbitals not been arranged like that.