Group 13 elements show +1 and +3 oxidation states. Relative statibility of +3 oxidation may be given as

Group 15 elements exhibit + 3 and + 5 oxidation states + 3 oxidation state is more stable than + 5 in case of :

Elements of group 14 exhibit oxidation state of

The Elements of group 14 show ----- oxidation states

How does the stability of +1 and +3 oxidation states vary in group 13?

The heavier members of 13 and 14 groups besides the group oxidation state also show another oxidation state. Down the group (darr) , the stability of higher oxidation state increases. This concept which is commonly called inert pair effect has been used to explain many physical and chemical properties of the element of these groups. Heavier members of group 13 exhibit oxidation state.