What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions.
(i) `F^(-)` (ii) Ar (iii) `Mg^(2+)` (iv) `Rb^(+)`

Explanation

The species (atoms or ions of different elements) having the same number of electrons but different magnitude of nuclear charge are called isoelectronic species.
`Mg^(2+)` has 10 (12- 2 = 10) electrons. The species isoelectronic with it are :
`N^(3-)(7+3=10),O^(2-)(8+2=10)`,
`F^(-)(9+1=10),Ne(10),Na^(+)(11-1=10),` etc.