Question

An atom of an element $A$ has three electrons in its outermost orbit and that of $B$ has six electrons in its outermost orbit. The formula of the compound between these two will be:

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

Answer 1

Answer: (B)

$A_2{B}_3$

$A$ has 3 electrons in outermost orbit and $B$ has 6 electrons in its outermost orbits. So $A$ can give three electrons to complete its octet and $B$ need 2 electrons to complete its octet. so 2 atoms of $A$ will release 6 electrons and 3 atoms of $B$ will need six electrons to complete their octet

So, the formula will be $A_2{B}_3$.