Question

The number of valence electrons in the elements A and B are 3 and 6 respectively. The most probable compound formed from A and B is:

• A. $A_{2}B$
• B. $A{B}_2$
• C. $A_6{B}_3$
• D. $A_2{B}_3$

Answer 1

The correct option is D $A_2{B}_3$

Given:

• The number of valence electrons in A is 3.
• The number of valence electrons in B is 6.

To get the nearest noble gas configuration, A has to loose 3 electrons to form $A^{3+}$ and B has to gain 2 electrons to form $B^{2-}$.

Using the crisscross method, The compound formed is $A_2{B}_3$.