JEE Main · 2021 · 01 Sep 2021 · Shift 2 · d and f Block Elements

Identify the element for which electronic configuration in +3 oxidation state is

[Ar] 3 d^{5}

Answer: (C)

Solution

If the

+ 3

ion is

[Ar] 3 d^{5}

, the neutral atom has these five

3 d

electrons plus the three lost on ionisation, giving a

3 d^{6} 4 s^{2}

ground state. That atom is iron, which loses the two

4 s

and one

3 d

electron to give

F e^{3 +} = [Ar] 3 d^{5}

. The element is iron.

JEE Main · 2021 · 01 Sep 2021 · Shift 2 · Single correct option