Which of the following correctly describes the orbital diagram for the Cd^{2+} ion?

• A. All orbitals up to 4d are fully filled, with 5s empty.
• B. The 4d subshell has 10 electrons, and the 5s subshell has 2 electrons.
• C. The 4d subshell has 8 electrons, and the 5s subshell has 2 electrons.
• D. The 4d subshell has 10 electrons, and the 5s subshell is half-filled.

Answer: (A)

Verified step by step guidance

1. Step 1: Identify the atomic number of the neutral Cd (Cadmium) atom, which is 48. This means a neutral Cd atom has 48 electrons.
2. Step 2: Write the electron configuration for neutral Cd. The configuration ends with the 4d and 5s subshells, specifically: \([\text{Kr}]\,4d^{10}\,5s^{2}\).
3. Step 3: Determine the electron configuration for the Cd\(^{2+}\) ion by removing 2 electrons from the neutral atom. Electrons are removed first from the outermost shell, which is the 5s subshell before the 4d subshell.
4. Step 4: After removing 2 electrons from the 5s subshell, the Cd\(^{2+}\) ion electron configuration becomes \([\text{Kr}]\,4d^{10}\,5s^{0}\), meaning the 4d subshell is fully filled with 10 electrons and the 5s subshell is empty.
5. Step 5: Use this information to select the correct description of the orbital diagram: all orbitals up to 4d are fully filled, with 5s empty.