Write the ground state electron configuration for the following element:
Magnesium   (Z = 12)  

• A.
• B.
• C.
• D.
• E.

Answer: (D)

Verified step by step guidance

1. Identify the atomic number of magnesium, which is 12. This means magnesium has 12 electrons in its neutral state.
2. Understand the order of filling electron orbitals based on the Aufbau principle, which states that electrons fill orbitals starting from the lowest energy level to the highest. The order is: 1s, 2s, 2p, 3s, 3p, etc.
3. Begin filling the orbitals with electrons: Start with the 1s orbital, which can hold 2 electrons. So, 1s².
4. Next, fill the 2s orbital, which also holds 2 electrons. So, 2s².
5. Continue with the 2p orbital, which can hold up to 6 electrons. So, 2p⁶. Finally, place the remaining 2 electrons in the 3s orbital, resulting in 3s².