Question

The electron configuration for $Cu$ is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}3d^{10}$.
Based on the electron configuration, what can be said about the relative ionization energies of the electrons in $n=3$?

• A. The ionization energies gradually decrease from s to p to d subshells.
• B. The ionization energies gradually increase from s to p to d subshells.
• C. The ionization energies are relatively the same from s to p to d subshells.
• D. The ionization energies are unpredictable at this energy level.

Answer 1

The correct option is A The ionization energies gradually decrease from s to p to d subshells.

Thus, ionization energy increases from left to right on the periodic table. Another factor that affects ionization energy is electron shielding. Electron shielding describes the ability of an atoms's inner electrons to shield its positively-charged nucleus from its valence electrons.

Thus the ionization energy decreases from $s$ to $p$ to $d$ sub shells.