Question

Element A has three electrons in the outermost orbit and B has six electrons in the outer most orbit. The formula of the compound will 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${}_3$

$A$ can lose $3$ electrons to form $A^{3+}$ ion. $B$ can gain two electrons to form $B^{2-}$ ion.

Two $A^{3+}$ ions combine with three $B^{2-}$ ions to form the compound $A_2{B}_3$.