Question

Elements of group 1 and group 17 have same valency

Answer 1

This is because elements of group 1 have 1 electron in valence shell so they can donate 1 electron whereas in group 17 elements have 7 electrons in valence shell so they can accept 1 electron. Valency is the combining capacity of an element. Elements of group 1 and group 17, both are univalent (both have valency 1).

Answer 2

Answer:

Explanation:

(i) All the elements in a group have the same number

of electrons in the outermost shell. Therefore,

down the group, valency remains the same.

(ii) Valency of group 1 elements is 1 and that of group

2 elements is 2.

(iii) The valency of group 18 elements is zero because

they are noble gases with completed outermost

shell.