In any period, the valency of an element with respect to oxygen

In any period of the periodic table, valency of an element with respect to oxygen

Balu (B) : Valence of an element with respect to hydrogen is the number of hydrogen atoms with which one atom of that element chemically combines. Venu (V) : Valence of an element with respect to oxygen is twice the number of oxygen atoms which one atom of that element combines.

What is the valency of IVA group elements with respect to hydrogen ?

Highest group valency of halogens with respect to oxygen is

The valency of any element of group 18 is

What is the valency possible to Arsenic with respect to oxygen and hydrogen?

What is the valency possible to arsenic with respect to oxygen and hydrogen?