Q57. The 'spin only' magnetic moment value of $\mathrm { MO } _ { 4 } { } ^ { 2 - }$ is $\_\_\_\_$ BM. (Where M is a metal having least metallic radii. among $\mathrm { Sc } , \mathrm { Ti } , \mathrm { V } , \mathrm { Cr } , \mathrm { Mn }$ and Zn ). (Given atomic number:\\
$\mathrm { Sc } = 21 , \mathrm { Ti } = 22 , \mathrm {~V} = 23 , \mathrm { Cr } = 24 , \mathrm { Mn } = 25$ and $\mathrm { Zn } = 30$ )\\