The first ionization energies of the elements __________ as you go from left to right across a period of the periodic table, and __________ as you go from the bottom to the top of a group in the table.
A)increase, increase
B)increase, decrease
C)decrease, increase
D)decrease, decrease
E)are completely unpredictable

Question

Quizplus · Accepted Answer

The first ionization energy increases as you go from left to right across a period because the number of protons in the nucleus is increasing, leading to a greater attraction for the electrons, which requires more energy to remove. The first ionization energy also increases as you go from the bottom to the top of a group because the size of the atom decreases and the electrons are held more tightly to the nucleus, again requiring more energy to remove.

The First Ionization Energies of the Elements __________ as You