Question

In which of the following pairs, the ions are isoelectronic ?
A. `Na^(+), Mg^^(2+)`
B. `Al^(3+), O^(-)`
C. `Na^(+), O^(2-)`
D. `N^(3), Cl^(-)`

Answer 1

Correct Answer - A::C
`Na^(+) = 11 -1 = 10 e^(-), Mg^(2+) = 12 -2 = 10 e^(-)`. Thus, they have same no. of electrons
`Al^(3+) = 13 -3 = 10 e^(-), Q^(2-) = 8 + 2 = 10 e^(-)`. They have same no. of electrons
`N^(3-) = 7 + 3 = 10 e^(-), Cl^(-) = 17 + 1 = 18 e^(-)`. They do not have same no. of electrons