Question

(a) Define the following terms:; (i) Valency; (ii) Atomic size; (b) How do the valency and' the atomic size of the elements vary while going from left to right along a period in the modern periodic table?(Delhi - 2014)

Answer 1

Answer:

a.

1. Valency is the ability of an atom to lose,share or gain an electron in order to obtain the octet structure.
2. Atomic size is the distance between the valence shell from the nucleus

b. As we go left to right in a period the atomic size decreases

As the number of electron increases and the nucleus pulls the valence electrons towards it and the atomic radius decreases