In which of the following is(are) the electron configuration(s) correct for the species indicated? a. \(\mathrm{Cu} \quad[\mathrm{Ar}] 4 s^{2} 3 d^{9}\) b. \(\mathrm{Fe}^{3+} \quad[\mathrm{Ar}] 3 d^{5}\) c. \(\mathrm{Co} \quad[\mathrm{Ar}] 4 s^{2} 3 d^{7}\) d. La \(\quad[\mathrm{Ar}] 6 s^{2} 4 f^{1}\) e. \(\mathrm{Pt}^{2+} \quad[\mathrm{Xe}] 4 f^{14} 5 d^{8}\)

#tag_title#Step 2: Calculate the electron configurations for each species.#tag_content#Using the atomic numbers, we can now write the electron configurations for each species, including charge considerations. a. Cu should have the electron configuration: \([\mathrm{Ar}] 4s^1 3d^{10}\) due to the increased stability of a filled d orbital. b. Fe³⁺ would have 3 less electrons than neutral Fe, so its electron configuration should be: \([\mathrm{Ar}] 3d^5\). c. Co should have the electron configuration: \([\mathrm{Ar}] 4s^2 3d^7\). d. La should have the electron configuration: \([\mathrm{Xe}] 6s^2 5d^1\), since it is the first member of the d-block after the f-block. e. Pt²⁺ would have 2 less electrons than neutral Pt, so its electron configuration should be: \([\mathrm{Xe}] 4f^{14} 5d^{8}\). #tag_title#Step 3: Compare calculated configurations with given configurations.#tag_content#Now, compare the calculated electron configurations with the given ones in the question. a. Given: \([\mathrm{Ar}] 4s^2 3d^9\), Correct: \([\mathrm{Ar}] 4s^1 3d^{10}\) - Incorrect b. Given: \([\mathrm{Ar}] 3d^5\), Correct: \([\mathrm{Ar}] 3d^5\) - Correct c. Given: \([\mathrm{Ar}] 4s^2 3d^7\), Correct: \([\mathrm{Ar}] 4s^2 3d^7\) - Correct d. Given: \([\mathrm{Ar}] 6s^2 4f^1\), Correct: \([\mathrm{Xe}] 6s^2 5d^1\) - Incorrect e. Given: \([\mathrm{Xe}] 4f^{14} 5d^{8}\), Correct: \([\mathrm{Xe}] 4f^{14} 5d^{8}\) - Correct Based on the comparison, options b, c, and e have the correct electron configurations.