Write out the ground-state electron configurations of (a) \(\mathrm{Sc}^{2+}\) (b) \(\mathrm{Mo}^{2+}\) (c) \(\mathrm{Rh}^{3+}\), (d) \(\mathrm{Fe}^{3+}\).

Using a periodic table, find the electron configurations of Sc, Mo, Rh, and Fe.

For each ion, remove the number of electrons specified by the charge (e.g., remove 2 electrons for Sc^(2+) and Mo^(2+), 3 electrons for Rh^(3+) and Fe^(3+)).

After removing the appropriate number of electrons, write the new electron configurations for each ion. Here are the detailed steps for each ion: (a) Sc^(2+) 1. The ground-state electron configuration of Sc (neutral atom) is \([Ar] 3\text{d}^1 4\text{s}^2\). 2. To get Sc^(2+), remove 2 electrons: first remove both 4s electrons. 3. The new electron configuration is \([Ar] 3\text{d}^1\). (b) Mo^(2+) 1. The ground-state electron configuration of Mo (neutral atom) is \([Kr] 4\text{d}^5 5\text{s}^1\). 2. To get Mo^(2+), remove 2 electrons: first remove the 5s electron, and then remove one of the 4d electrons. 3. The new electron configuration is \([Kr] 4\text{d}^4\). (c) Rh^(3+) 1. The ground-state electron configuration of Rh (neutral atom) is \([Kr] 4\text{d}^8 5\text{s}^1\). 2. To get Rh^(3+), remove 3 electrons: first remove the 5s electron, and then remove two of the 4d electrons. 3. The new electron configuration is \([Kr] 4\text{d}^6\). (d) Fe^(3+) 1. The ground-state electron configuration of Fe (neutral atom) is \([Ar] 3\text{d}^6 4\text{s}^2\). 2. To get Fe^(3+), remove 3 electrons: first remove both 4s electrons, and then remove one of the 3d electrons. 3. The new electron configuration is \([Ar] 3\text{d}^5\).