Calculated spin only magnetic moment of `Cr^(x+)` is 4.9 BM. Find the 'x' value.

Explanation

Magnetic moment `mu= 4.9 BM = sqrt(n(n+2))`
Number of unpaired electrons `= n = 4`
with four unpaired electrons, the configuration is `3d^(4)4s^(0)`.
`Cr^(2+)` ion posses 4 unpaired electrons, thus .x. value is 2.