Question

Which ion has maximum size? (a) o-2(b)Na+(c) Al+3(d)Mg+2

Answer 1

Option A is correct

All ion having same number of electron like in O-2 =10electron, in Na+, Al+3, Mg+2 all having 10electron . there is formula for defined the size of atom , Z effective(Z*) = Z- sigma* here Z effective attractive power between nucleus and outermost electron and sigma* for repulsive power between outermost electron and another electron and Z is atomic no. here electron is same then sigma* is same and Z for Oxygen is 8, for Na is 11, for Mg is 12, and Al is 13 then if minimum no. of Z then Z* is also minimum so size is maximum