Question

valency of an element X is 3. write the chemical formula of its oxide

Answer 1

          If the valency of an element is 3,.

=> The chemical formula of its oxide will be,

=>    X     O
            /\
        3     2

=> $X_2O_3$

                  Hope it Helps !!

Answer 2

Valency of X = 3
Formula of its oxide = X2O3

For ex:-
Atomic no. of Aluminium = 13
Electronic configuration = 2,8,3
Valency = 3

Formula of its oxide = Al2O3

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