Hich of the following elements has the smallest first ionization energy? How do you determine this?
a. sodium
b. calcium
c. potassium
d. magnesium
a. sodium
b. calcium
c. potassium
d. magnesium
1 Answer
Oct 17, 2016
Ionization energy decreases DOWN a Group, and increases from left to right across a Period as we face the Periodic Table.
Explanation:
The order of ionization energies is thus (smallest to largest):
As a chemist, as a physical scientist, you should, however, always examine the data. Here is a start.
That ionization energy should decrease down a Group, down a column of the Periodic Table, is reasonable, because the valence electron is farther removed from the nuclear core. Across the Period, across a row, from left to right the ionization energy should increase because we add nuclear charge that is imperfectly shielded by the valence electrons.
