Question

An element $A$ combines with oxygen to form an oxide $AO$. Find the group to which the element $A$ belongs.

• A. $IA$
• B. $IIA$
• C. $IIIA$
• D. $IVA$

Answer 1

Answer: (B)

$IIA$

The valency of $O^{2-}$ is $2$. Thus valency of A is $2$. Also the oxide is conducting hence A is a metal, as oxides of metals are conducting. Thus the metal of valency $2$ belongs to group $IIA$. Hence the answer is option B-$IIA$.