Question

The aqueous solution containing which one of the following ions will be colourless
(Atomic number `Sc = 21, Fe = 26, Ri = 22, Mn = 25)`
A. `Mn^(2+)`
B. `Fe^(2+)`
C. `Ti^(3+)`
D. `Sc^(3+)`

Answer 1

Correct Answer - D
`._(21)Sc rarr 1 s^(2) 2 s^(2) 2p^(6) 3s^(2) 3p^(6) 4s^(2) 3d^(1)`
`Sc^(+ 3) rarr s^(2) 2s^(2) - 2[.^(6) 3s^(2) 3p^(6)]`