Question

Which one of the following does not increase while moving down the group of the periodic table?

(a) atomic radius (b) metallic character (c) valence electrons (d) shells in the atoms

Answer 1

(a) Atomic radii of elements gradually increase in a group from top to bottom. As the atomic number increases, the number of shells increases, the distance of valence electrons from the nucleus to the outermost shell increases. As a result of this, the force of attraction between the nucleus and the valence electron decreases. Therefore, the atomic radius increases on moving down a group.
(b) Down the group, atomic size increases due to which the effective nuclear charge experienced by valence electrons decreases. Therefore, these valance electrons can be lost easily. Hence, the metallic character increases down the group.
(c) Down the group, The number of valence electrons remains the same, hence it does not increase.
(d) Down the group, As the atomic number increases, the number of shells increases.

Hence the correct option is c.