Select the single best answer.
Choose the correct orbital diagram for the ground-state electron arrangement for aluminum. Be sure to
follow the three orbital filling rules: the aufbau principle, the Pauli exclusion principle, and Hund's
rule.
1s 2s
2p 3s 3p
TUTUTUTUTUTUT ↑
1s 2s 2p 3s
3p
1s 2s 2p 3s
3p
TUTU TUTUTU↑↑↑
1s 2s
2p 3s
3p
tititttit ↑↑



Answer :

The correct orbital diagram for the ground-state electron arrangement for aluminum can be determined by following the three orbital filling rules: the aufbau principle, the Pauli exclusion principle, and Hund's rule. 1. Aufbau Principle: Electrons fill orbitals starting from the lowest energy level to the highest. 2. Pauli Exclusion Principle: Each orbital can hold a maximum of 2 electrons with opposite spins. 3. Hund's Rule: Electrons occupy orbitals of the same energy singly before pairing up. In the case of aluminum (atomic number 13), the electron configuration is 1s² 2s² 2p⁶ 3s² 3p¹. This can be represented in the orbital diagram as follows: - The first shell (1s) contains 2 electrons (↑↓). - The second shell (2s) contains 2 electrons (↑↓). - The second shell (2p) contains 6 electrons (↑↑↑↑↑↑). - The third shell (3s) contains 2 electrons (↑↑). - The third shell (3p) contains 1 electron (↑). Therefore, the correct orbital diagram for the ground-state electron arrangement of aluminum would be: 1s² 2s² 2p⁶ 3s² 3p¹ ↑↓ ↑↓ ↑↑↑↑↑↑ ↑↑ ↑