Niobium (Nb; Z = 41) has an anomalous ground-state electron configuration for a Group 5B (5) element: [Kr] 5s¹4d⁴. What is the expected electron configuration for elements in this group? Draw partial orbital diagrams to show how paramagnetic measurements could support niobium's actual configuration.

Niobium has an anomalous ground-state electron configuration for a Group 5 element: [Kr] 5s¹4d⁴. IT is anomalous because in normal course, it should have been [Kr] 5s²4d³ Or [Kr] 5s⁰4d⁵. It is so because 5s subshell

has lesser energy than 4d subshell, or half filled 4d subshell is more stable. But the stable configuration is [Kr] 5s¹4d⁴. It is so because the energy gap between 5s and 4d is very little. So one electron of 5s² gets Transferred to 4d subshell. This paramagnetic behavior is confirmed by its dipole moment, equivalent to 5 unpaired electrons.