c) t₂g² eg⁴ , In crystal field theory, the d orbitals split into two sets of different energy levels in an octahedral crystal field. The t₂g set consists of the lower energy d orbitals (dxy, dyz, dzx), while the eg set consists of the higher energy d orbitals (dx²-y², dz²).
For a d⁶ configuration, there are 6 electrons in the d orbitals. According to the Aufbau principle, electrons fill the lower energy orbitals before filling higher energy orbitals. Therefore, in terms of t₂g and eg:
d⁶ configuration: t₂g² eg⁴
This means that there are 2 electrons in the t₂g orbitals and 4 electrons in the eg orbitals.
