Which simplified electron configuration correctly represents aluminum (Al, atomic number 13)?

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

Answer: (D)

Verified step by step guidance

1. Identify the atomic number of aluminum (Al), which is 13. This means aluminum has 13 electrons to place in its electron configuration.
2. Recall the order in which electron orbitals are filled according to the Aufbau principle: 1s, 2s, 2p, 3s, 3p, and so on.
3. Fill the orbitals with electrons following the maximum capacity of each: 1s can hold 2 electrons, 2s can hold 2, 2p can hold 6, 3s can hold 2, and 3p can hold 6.
4. Add electrons in order until you reach 13 total electrons: fill 1s with 2, 2s with 2, 2p with 6, 3s with 2, and then place the remaining 1 electron in the 3p orbital.
5. Write the simplified electron configuration using the format \(1\text{s}^2 2\text{s}^2 2\text{p}^6 3\text{s}^2 3\text{p}^1\), which correctly represents aluminum's electron arrangement.