X is a metal from Group II. When X carbonate is heated in a Bunsen flame, it breaks down to form carbon dioxide and a white solid residue, and these are the only products. The white solid residue dissolves only slightly in water. Even if large quantities of the solid residue are added to water, the pH of the saturated solution is lower than that of limewater. What could be the identity of X?
- Amagnesium
- Bcalcium
- Cstrontium
- Dbarium