Which one of the following group of atoms or ions is not isoelectronic ?

Options

A. `He, H^(ɵ), Li^(o+)`
B. `Na^(o+), Mg^(2+), Al^(3+)`
C. `F^(ɵ), O^(2-), N^(3-)`
D. `K^(o+), Ca^(2+), Ne`

Answer

D

Explanation

`{:(K^(o+)",",(Z=19)",""no. of" e^(-)'s=19 - 1 = 18,),(ca^(2+)",",(Z=20)"," "no. of" e^(-)'s = 20-2 =18,),(Ne",",(Z=10)"," "no. of" e^(-)'s = 10,):}]` Hence not isoelectronic