Question

the pair of ions have same electronic configuration is :
(a)Cr3+,Fe3+
b)Fe3+,Mn2+
c)Fe3+,Co3+
d)Sc3+,Cr3+

Answer 1

The electronic configuration of Cr = [Ar]18 3d5 4s1

                                                Cr3+ = [Ar]18 3d3 4s0

the electronic configuration of Fe =  [Ar]18 3d6 4s2

                                               Fe3+ = [Ar]18 3d5 4s0

the electronic configuration of Mn = [Ar]18 3d5 4s2

                                              Mn2+ = [Ar]18 3d5 4s0

the electronic configuration of Co = [Ar]18 3d7 4s2

                                              Co3+ = [Ar]18 3d6 4s2

the electronic configuration of Sc = [Ar]18 3d1 4s2

                                              Sc3+ = [Ar]18 3d0 4s0 [noble gas configuration]

hence,,  option B is correct i.e.,Fe3+ = Mn2+ = [Ar]18 3d5 4s0

Answer 2

Answer:

(b) Fe3 + , Mn2+

Explanation:

MARK ME AS BRAINIEST PLZ