JEE Main202225 Jun 2022Evening ShiftChemistryd and f Block ElementsActual
The metal ion (in gaseous state) with lowest spin-only magnetic moment value is
Options
- AV 2 +
- BNi 2 +
- CCr 2 +
- DFe 2 +
Correct answer
B. Ni 2 +
Step-by-step solution
Ion Electronic configuration No. of unpaired electron 1 Cr 2 + 3 d 4 4 2 V 2 + 3 d 3 3 3 Fe 2 + 3 d 6 4 4 Ni 2 + 3 d 8 2 Magnetic moment(spin only) is calculated by the formula μ =   n ( n + 2 )   BM . Magnetic moment (spin only)is directly proportional to the number of unpaired electrons. Hence, less is the number of unpaired electrons less is the magnetic moment (spin only). As Ni 2+ has the least number of unpaired electrons it has the least magnetic moment (spin only) among the given options.