Write down the electronic configuration of: ltBrgt (i) `Cr^(3+)`
(ii) `Pm^(3+)`
(iii)`Cu^(+)`
(iv) `Ce^(4+)`
`Co^(2+)`
(vi) `Lu^(2+)`
(vii) `Mn^(2+)`
(viii) `Th^(4+)`

Explanation

(i). `Cr(Z=24)implies3d^54s^1,Cr^(3+)=3d^3`
(ii). `Cu(Z=29)implies3d^(10)4s^1,Cr^(o+)3d^(10)`
(iii). `Co(Z=27)implies3d^74s^2,Co^(2+)=3d^7`
(iv). `Mn(Z=25)implies3d^54s^2,Mn^(2+)=3d^5`
(v). `Pm(Z=61)implies4f^56s^2,Pm^(3+)=4f^4`
(vi). `Ce(Z=58)implies4f^15d^16s^2,Ce^(4+)=4f^0` (vii). `Lu(Z=71)implies4f^(14)5d^16s^2,Lu^(2+)=4f^(14)5d^(1)`
(viii). `Th(Z=90)implies5f^06d^27s^2,Th^(4+)=5f^0`