Do noble gases have high or low ionization energies?

1 Answer
Dec 12, 2016

Ionization energies increase across a Period from left to right as we face the Table............

Explanation:

.........And ionization energies decrease down a Group.

Thus Noble Gases have exceptionally high ionization energies.

Simply considerations of electrostatics should rationalize this trend. As nuclear charge increases in the same Period, ionization energy progressively increases. It reaches a maximum when the valence electronic shell is complete.

https://tse1.mm.bing.net/th?id=OIP.M1b1fd9c8fc83d3a2a091be0d9e0341ceo0&pid=15.1&P=0&w=198&h=153

This diagram is well-used, and illustrative.