Position of three elements A, B and C in the periodic table is shown below : Giving reasons explain : (a) Element A is a metal. (b) Element B has larger atomic size than the element C. (c) Element C has a valency of one.

Position of three elements A, B and C in the periodic table is shown b

1.	Position of three elements A, B and C in the periodic table is shown below : Giving reasons explain : (a) Element A is a metal. (b) Element B has larger atomic size than the element C. (c) Element C has a valency of one.
Answer» Solution :(a) Element A belongs to group I and period 3. It is sodium (NA) and is a metal. (b) We know that the atomic size of the ELEMENTS decreases along a period and increases down a group. The element B (group II and period 3) has larger atomic size than the element C (group II and period 2). (c) Element C is a member of halogen family. It is FLUORINE (F) and its valency is 1 (8 - 7 = 1).