The magnetic moment of $\mathrm{Cr}$, $\mathrm{Mn}$, $\mathrm{Fe}$  and $\mathrm{Cu}$ are in the order 

Metallic radii of some transition elements are given below Which of these elements will have the highest density?

Which of the following reactions are disproportionation reactions?

${\mathrm{Cu}}^{+}⟶{\mathrm{Cu}}^{2+}+\mathrm{Cu}$

$3{\mathrm{MnO}}_4^{2-}+4{\mathrm{H}}^{+}⟶2{\mathrm{MnO}}_4^{-}+{\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$

$2{\mathrm{KMnO}}_4⟶{\mathrm{K}}_2{\mathrm{MnO}}_4+{\mathrm{MnO}}_2+{\mathrm{O}}_2$

$2{\mathrm{MnO}}_4^{-}+3{\mathrm{Mn}}^{2+}+2{\mathrm{H}}_2\mathrm{O}⟶5{\mathrm{MnO}}_2+4{\mathrm{H}}^{+}$