The oxoanion in which the oxidation state of the central atom is same as its group number in the periodic table is
$SO_4^{2-}$
$VO_2^-$
$MnO_4^{2-}$
$Cr_2O_7^{2-}$
Which is most reactive metal
Which of the following pairs involves isoelectronic ions
Mark the variety of iron which has highest melting point
Among $Co ^{3+}, Ti ^{2+}, V ^{2+}$ and $Cr ^{2+}$ ions, one if used as a reagent cannot liberate $H _{2}$ from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is $......B.M$. (Nearest integer)
The correct order of spin only magnetic moments for the following complex ions is