Question

sodium magnesium and Aluminium are the elements having 123 Valence Electrons respectively which of these elements has the largest atomic radius and is least reactive justify your answer starting reason of each

Answer 1

Largest atomic radii is of sodium due less number of electrons due to which the nuclear charge also decreased.
Least reactive is aluminum because more energy will be required to remove its Valence electrons than the other two.

Answer 2

largest atomic radius is of sodium because atomic radius decreases when we move left to right in a group
aluminium is least reactive element as it is difficult to remove 3 electrons from outermost shell