Justify the following statements:
a) Cations are smaller in size than the corresponding atom.
b) Size of the atom increases as we move down a group.
c) Atomic size decreases as we move across a period.

Explanation

a) Cations would have lost outermost-shell electrons and hence their size is smaller than the corresponding atom.
b] Addition of new shells, going down a group, increases the distance between the outermost electrons and the nucleus.
c] Increase in nuclear charge, tending to pull electrons closer to the nucleus, reduces the atomic size of elements, along a period.