Question

which electron configuration is allowed in consideration of hunds rule?
1s²2s²2p⁴3s²
1s²2s²2p⁶3s²3p⁶4s¹3d²
1s²2s²2p⁶3s²
1s²2s²2p⁶3s²3p⁴4s²
question 3 (1 point)

Explanation:

Hund's rule is about electron filling in orbitals. But here, the key is the order of filling orbitals. Electrons fill lower - energy orbitals first. The order of filling is \(1s<2s<2p<3s<3p<4s<3d\).

• For \(1s^{2}2s^{2}2p^{4}3s^{2}\), electrons should fill \(2p\) completely (\(2p^{6}\)) before going to \(3s\).
• For \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}3d^{2}\), electrons should fill \(4s\) completely (\(4s^{2}\)) before filling \(3d\).
• For \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{4}4s^{2}\), electrons should fill \(3p\) completely (\(3p^{6}\)) before going to \(4s\).
• For \(1s^{2}2s^{2}2p^{6}3s^{2}\), it follows the \(1s<2s<2p<3s\) order of filling orbitals.

Answer:

\(1s^{2}2s^{2}2p^{6}3s^{2}\)