Which one of the following sets of ions represents the collection of isoelectronic species?

Options

A. `Na^(+), Mg^(2+), A1^(3+), C1^(-)`
B. `K^(+),Ca^(2+), Sc^(3+), C1^(-)`
C. `Na^(+), Ca^(2+), Sc^(3+), F^(-)`
D. `K^(+), C1^(-), Mg^(2+), Sc^(3+)`

Answer

B

Explanation

Isolectronic species are characterized by identical electronic configuration. `K^(+),Ca^(2+),Sc^(3+)`, and `C1^(-)`, all have the same electron configuration:
`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)`