The magnetic moments of few transition metal ions are given below : {:("Metal ion",,,"Magnetic moment (BM)"),(Sc^(3+),,,0.00),(Cr^(2+),,,4.90),(Ni^(2+),,,2.84),(Ti^(3+),,,1.73):} (At. no. Sc = 21, Ti = 22, Cr = 24, Ni = 28) Which of the given metal ions : (i) has the maximum number of unpaired electrons ? (ii) forms colourless aqueous solution ? (iii) exhibits the most stable +3 oxidation state ?

The magnetic moments of few transition metal ions are given below : {

1.	The magnetic moments of few transition metal ions are given below : {:("Metal ion",,,"Magnetic moment (BM)"),(Sc^(3+),,,0.00),(Cr^(2+),,,4.90),(Ni^(2+),,,2.84),(Ti^(3+),,,1.73):} (At. no. Sc = 21, Ti = 22, Cr = 24, Ni = 28) Which of the given metal ions : (i) has the maximum number of unpaired electrons ? (ii) forms colourless aqueous solution ? (iii) exhibits the most stable +3 oxidation state ?
Answer» Solution :(i) As `Cr^(2+)` SHOWS the maximum magnetic moment, it has the maximum number of unpaired electrons. (II) The configuration of `Sc^(3+)` ion is `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6)`. As all the ORBITALS are completely filled, there is no possibility of excitation of electrons. It forms a colourless AQUEOUS solution. (iii) Again because of completely filled orbitals, `Sc^(3+)` shows the most STABLE +3 oxidation state.