What is meant by a group in the Modern Periodic Table? How do the following change on moving from top to bottom in a group?
i] Number of valence electrons
ii] Number of occupied shells
iii] Size of atoms
iv] Metallic character of elements
v] Effective nuclear charge experienced by valence electrons

Explanation

Vertical columns of the periodic table are known as groups.
(i) The number of valence electrons remains constant when we move down the group.
(ii) The number of occupied shells increases down the group.
(iii) The size of atom increases down the group.
(iv) The metallic character of elements increases down the group.
(v) The effective nuclear charge decreases down the group.