Energy difference between t2g and EG level in octahedral complex is denoted by ​

∆o

Explanation:

Usually, the d level consists of a set of five degenerate d orbitals. These orbitals rema degenerate until the approach of ligands.

When ligands approach, the d orbitals are split into higher energy eg and lower energy t2g orbitals.

There exists an energy difference between this t2g and eg levels. This energy difference is called the octahedral crystal field splitting denoted as ∆o.

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