How would the electronegativity and first ionization energy

values of lithium compare with the same values of oxygen?
Why?

Li is 1s2 2s1 and O is 1s2 2s2 2p4. Li wants to LOSE that outside electron while O wants to GAIN electrons. Electronegativity is a measure of the ability of an atom to gain electrons; therefore, O should be higher for EN values (and it is).

Looking at the ionization potential (IP), that is the energy required to remove the outside electron (for the first IP). With Li, that outside electron, to be removed, must be pulled from an effective nuclear charge of +1 (the nucleus is +3 protons, there are two electrons between the nucleus and the outside one which shields some of the nuclear charge) and 3-2 = 1. With O, there are 8 protons in the nucleus, the outside electron is shielded by 4 so the force to remove an outside electron must pull against approximately 8-4 = 4; therefore, the IP for O should be higher than the IP for Li (and it is).