Which of the following represents the complete ground state electron configuration for a titanium (Ti) atom?

• A. 1s^2 2s^2 2p^6 3s^2 3p^6 3d^4
• B. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2
• C. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^4
• D. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 4p^2

Answer: (B)

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 to be placed in orbitals according to the Aufbau principle.
2. Step 2: Recall the order of orbital filling based on increasing energy levels: 1s, 2s, 2p, 3s, 3p, 4s, then 3d. Electrons fill lower energy orbitals first before moving to higher ones.
3. Step 3: Write the electron configuration by filling orbitals in order until all 22 electrons are assigned: start with 1s^2, then 2s^2, 2p^6, 3s^2, 3p^6, then 4s^2, and finally 3d electrons.
4. Step 4: Count the electrons assigned so far: 2 (1s) + 2 (2s) + 6 (2p) + 2 (3s) + 6 (3p) + 2 (4s) = 20 electrons. The remaining 2 electrons go into the 3d orbital, giving 3d^2.
5. Step 5: Confirm that the final electron configuration is \$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2$, which correctly accounts for all 22 electrons and follows the Aufbau principle.