What is meant by '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 element (v) Effective nuclear charge experienced by valence electrons



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 atoms increases down the group. (iv) The metallic character of elements increases down the group. (v) The effective nuclear charge decreases down the group.