Which one of the following ions has electronic configuration [Ar] 3d6 ? (At.no. Mn =25, Fe = 26,Co =27, Ni = 28)

Question

Which one of the following ions has electronic configuration [Ar] 3d6 ? (At.no. Mn =25, Fe = 26,Co =27, Ni = 28) (A) Ni3+  (B) Mn3+  (C) Fe3+  (D) Co3+

Tardigrade Admin · Accepted Answer

Ni3+(28)=[Ar]3d7 Mn3+(25)=[Ar]3d4 Fe3+(26)=[Ar]3d5 Co3+(27)=[Ar]3d6 Hence, Co3+ has 3d6 electronic configuration

Q. Which one of the following ions has electronic configuration $[A r] 3 d^{6} ?$
(At.no. $M n = 25, F e = 26, C o = 27, N i = 28)$

$N i^{3 +}$

$M n^{3 +}$

$F e^{3 +}$

$C o^{3 +}$

$N i^{3 +} (28) = [A r] 3 d^{7}$
$M n^{3 +} (25) = [A r] 3 d^{4}$
$F e^{3 +} (26) = [A r] 3 d^{5}$
$C o^{3 +} (27) = [A r] 3 d^{6}$
Hence, $C o^{3 +}$ has $3 d^{6}$ electronic configuration

Q. Which one of the following ions has electronic configuration [Ar]3d6? (At.no. Mn=25,Fe=26,Co=27,Ni=28)

Ni3+

Mn3+

Fe3+

Co3+