Which of the following will be coloured ion :
$Fe^{2+}$
$Cu^+$
$Sc^{3+}$
$Mn^{2+}$
On adding excess of $N{H_3}$ solution to $CuS{O_4}$ solution, the dark blue colour is due to
The term platforming is
The spin magnetic moment of cobalt in the compound $Hg[Co{(SCN)_4}]$ is
In a transition series, as the atomic number increases, paramagnetism
Which of the following statement(s) is(are) correct with reference to the ferrous and ferric ions