Question

Which electron configuration below represents a violation of the Pauli exclusion principle?

1) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹° 4p⁶ 5s² 4d¹° 5p⁶ 6s² 4f¹⁴ 5d¹° 6p⁶ 7s²
2) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹° 4p⁶ 5s² 4d¹° 5p⁶ 6s² 4f¹⁴ 5d¹° 6p⁶
3) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹° 4p⁶ 5s² 4d¹° 5p⁶ 6s² 4f¹⁴ 5d¹°
4) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹° 4p⁶ 5s² 4d¹° 5p⁶ 6s²

Answer 1

Option 3) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹° 4p⁶ 5s² 4d¹° 5p⁶ 6s² 4f¹⁴ 5d¹° 4 violates the Pauli exclusion principle by including the 6s² subshell before the 4f¹⁴ subshell.

Step-by-step explanation:

The electron configuration that represents a violation of the Pauli exclusion principle is option 3) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹° 4p⁶ 5s² 4d¹° 5p⁶ 6s² 4f¹⁴ 5d¹°4. The violation occurs in the inclusion of the 6s² subshell, which has already been filled out of sequence before the 4f¹⁴ subshell. According to the Pauli exclusion principle, each electron must maintain its unique identity, and thus, no two electrons can have the same set of quantum numbers.