The increase in size on the periodic table can be compared to the atomic radius on the table.
Elements in the same group on the periodic table can be regarded as a family.
Atomic radius is the property used to quantify the size of an atom. It is taken as half of the inter-nuclear distance between two covalently bonded atoms of a non-metal or the distance between the nuclei of two metals.
Across a nucleus, it decreases rapidly due to pull of the nucleus.
Atomic radius increases down a group on the periodic table.