Which of the following is the correct electron configuration for the Ti^{2+} ion?

• A. [Ar] 4s^2 3d^2
• B. [Ar] 4s^2 3d^0
• C. [Ar] 3d^2
• D. [Ar] 3d^4

Answer: (C)

Verified step by step guidance

1. Step 1: Identify the atomic number of titanium (Ti), which is 22. This means a neutral Ti atom has 22 electrons.
2. Step 2: Write the electron configuration for the neutral Ti atom. The order of filling is 1s, 2s, 2p, 3s, 3p, 4s, then 3d. So, Ti's configuration is \([Ar] 4s^2 3d^2\).
3. Step 3: Understand that when forming a \(Ti^{2+}\) ion, two electrons are removed. Electrons are removed first from the outermost shell, which is the 4s orbital before the 3d orbital.
4. Step 4: Remove the two electrons from the 4s orbital of the neutral Ti configuration, resulting in \([Ar] 3d^2\) for the \(Ti^{2+}\) ion.
5. Step 5: Confirm that the correct electron configuration for \(Ti^{2+}\) is \([Ar] 3d^2\), which matches the removal of electrons from the 4s orbital first.