A d-block element forms octahedral complex but its magnetic moment remains same either in strong field or in weak field ligand. Which of the following is/are correct ?

Options

A. Element always forms colourless compound
B. Number of electrons in `t_(2_(g))` orbitals are higher than in `e_(g)` orbitals
C. It can have either `d^(3)` or `d^(8)` configuration
D. It can have either `d^(7)` or `d^(8)` configuration

Answer

B, C

Explanation

* For `d^(3)` configuration :
In strong ligand field : `t_(2)^(3)eg^(0)` : In weak ligand field `:t_(2g)^(3)eg^(0)`
* For `d^(8)` configuration :
In strong ligand field : `t_(2g)^(6)eg^(2)` , In weak ligand field : `t_(2g)^(6)eg^(2)`