Give three examples of +2 ions that have an electron configuration of nd10 (n = 3, 4, 5...).

Verified step by step guidance

1. Step 1: Understand that the problem is asking for +2 ions with a full d subshell, specifically with an electron configuration of nd^10.
2. Step 2: Recall that transition metals often form +2 ions by losing their s electrons first, followed by d electrons if necessary.
3. Step 3: Identify transition metals that have a d^10 configuration in their neutral state. These are typically found at the end of the d-block in each period.
4. Step 4: Consider the electron configurations of neutral transition metals like Zinc (Zn), Cadmium (Cd), and Mercury (Hg), which have a d^10 configuration in their neutral state.
5. Step 5: Recognize that when these metals form +2 ions, they lose their s electrons, resulting in a d^10 configuration for the ion. Therefore, Zn^2+, Cd^2+, and Hg^2+ are examples of +2 ions with a d^10 configuration.