Which of the following is the correct electron configuration for a neutral atom of sodium (Na)?

• A. 1s^2 2s^2 2p^6 3p^1
• B. 1s^2 2s^2 2p^6 3s^2
• C. 1s^2 2s^2 2p^6 3s^1
• D. 1s^2 2s^2 2p^5 3s^2

Answer: (C)

Verified step by step guidance

1. Step 1: Determine the atomic number of sodium (Na), which tells you the total number of electrons in a neutral atom. Sodium has an atomic number of 11, so it has 11 electrons.
2. Step 2: Recall the order in which electron orbitals are filled according to the Aufbau principle: 1s, 2s, 2p, 3s, 3p, and so on.
3. Step 3: Fill the orbitals with electrons following the order and the maximum number of electrons each orbital can hold: 1s can hold 2, 2s can hold 2, 2p can hold 6, and 3s can hold 2.
4. Step 4: Add electrons to each orbital until you reach 11 electrons total: 2 in 1s, 2 in 2s, 6 in 2p, and the remaining 1 electron in 3s.
5. Step 5: Write the electron configuration based on the distribution: \$1s^{2} 2s^{2} 2p^{6} 3s^{1}$, which correctly represents the neutral sodium atom.