Question

Element A and 3 electron in the outermost orbit and elements B has 6electron in the outermost orbit. The formula of the compound formed between A and B would be:

• A. $A_2{B}_3$
• B. $A_2{B}_6$
• C. $A_{2}B$
• D. $A_3{B}_2$

Answer 1

Answer: (A)

$A_2{B}_3$

Element A has $3$ electrons in outermost shell so its valency is $3$. It will loose $3$ electrons to attain stability, as loss of $3$ electrons is easier than gain of $5$ electrons.

Valency of B is $-2$ as it will gain $2$ electrons to attain stability and combine with other atom.

Valency of A$⟶+3$

Valency of B$⟶-2$

(Refer to Image)

Cross multiply valency of A and B

$\therefore A_2{B}_3$ compound will be formed.