Which of the following order is/are correct? — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Step 1: Write down the electronic configurations of the given species: Cr ([Ar] 3d5 4s1), Fe3+ ([Ar] 3d5), and Cu+ ([Ar] 3d10). Step 2: In Cr and Fe3+, the d-subshell is half-filled, meaning each of the five d-orbitals (including d_xy) contains exactly 1 electron. In Cu+, the d-subshell is completely filled, so each d-orbital contains 2 electrons. Step 3: Thus, Cu+ has the maximum number of electrons (2) in the d_xy orbital, which is option (c).