Verified answer

Answer:

All the element in a group have same valency.

Additional information :

Variation of valency along period :

Firstly valency increase then it start decrease to zero.

Example :

Li , Be , B , C , N ,  O , F , Ne

Here valency Li to C firstly increase. But after N to Ne it decrease to zero.

Variable of valency in group :

Since number of valence electron in group remain same. Therefore , valency do not change.

Example :

H , Li , Na , K , Rb , Cs , Fr

Here valency remain same.