Write the full ground-state electron configuration for \(\mathrm{Ca}^{2+}, \mathrm{S}^{2-}, \mathrm{Ar}, \mathrm{K}^{+}\)

To identify each atom's position in the periodic table, use a periodic table to look for the atomic number, which represents the number of protons in a neutral atom. Since the ions/elements given are \(\mathrm{Ca}^{2+}, \mathrm{S}^{2-}, \mathrm{Ar}, \mathrm{K}^{+}\), we can determine their atomic numbers as follows: -Calcium (Ca): atomic number 20 -Sulfur (S): atomic number 16 -Argon (Ar): atomic number 18 -Potassium (K): atomic number 19

Now, we can write the electron configuration for each ion/element using the identified atomic numbers and accounting for the changes in electron numbers due to the charges on the ions. The electron configuration is written using subshells (s, p, d, f) and their occupancies. 1. \(\mathrm{Ca}^{2+}\): 10 less 2 electrons due to the charge, so 18 electrons Electron configuration: 1s², 2s², 2p⁶, 3s², 3p⁶ 2. \(\mathrm{S}^{2-}\): 16 plus 2 electrons due to the charge, so 18 electrons Electron configuration: 1s², 2s², 2p⁶, 3s², 3p⁶ 3. \(\mathrm{Ar}\): 18 electrons (neutral atom) Electron configuration: 1s², 2s², 2p⁶, 3s², 3p⁶ 4. \(\mathrm{K}^{+}\): 19 less 1 electron due to the charge, so 18 electrons Electron configuration: 1s², 2s², 2p⁶, 3s², 3p⁶ So, the full ground-state electron configurations for the given ions/elements are: - \(\mathrm{Ca}^{2+}\): 1s², 2s², 2p⁶, 3s², 3p⁶ - \(\mathrm{S}^{2-}\): 1s², 2s², 2p⁶, 3s², 3p⁶ - \(\mathrm{Ar}\): 1s², 2s², 2p⁶, 3s², 3p⁶ - \(\mathrm{K}^{+}\): 1s², 2s², 2p⁶, 3s², 3p⁶