The "spin-only" magnetic moment [ in units of Bohr magneton,$(\mu_B)$ ] of $Ni^{2+}$ in aqueous solution would be (At. No. $Ni = 28$).

The number of unpaired electrons in $Mn^{3+}$ is

An element of the $3d-$ transition series shows two oxidation states $x$ and $y$,which differ by two units. Then:

Match the metal ions given in Column-$I$ with the spin magnetic moments of the ions given in Column-$II$ and assign the correct code.

Column-$I$	Column-$II$
$(a) \ Co^{3+}$	$(i) \ \sqrt{8} \ B.M.$
$(b) \ Cr^{3+}$	$(ii) \ \sqrt{35} \ B.M.$
$(c) \ Fe^{3+}$	$(iii) \ \sqrt{3} \ B.M.$
$(d) \ Ni^{2+}$	$(iv) \ \sqrt{24} \ B.M.$
	$(v) \ \sqrt{15} \ B.M.$

$(a) \quad (b) \quad (c) \quad (d)$

Which of the following general configurations of the outermost shell represents the chromium element [$Cr$'s atomic number $= 24$]?

The correct set of ions (aqueous solution) with the same colour from the following is: