Question
For a $p -$ block element, its $3d, 3s, 3p$ and $4s$ orbitals are completely filled and the differentiating electron goes to the $4p$ orbital. The element should have its atomic number in the range
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$MnO _{4}^{-}+8 H ^{+}+5 e ^{-} \rightarrow Mn ^{2+}+4 H _{2} O$,
$E^{o} _{ Mn ^{2+} / MnO _{4}^{-}}=-1.510 \,V$
$\frac{1}{2} O _{2}+2 H ^{+}+2 e ^{-} \rightarrow H _{2} O$,
$E _{ O _{2} / H _{2} O }^{o}=+1.223 \,V$
Will the permanganate ion, $MnO _{4}^{-}$liberate $O _{2}$ from water in the presence of an acid ?
