Question

What element does the carbonate (CO32-) molecule bond with to form the shells of these organisms?


Hydrogen ions (H+)


Calcium (Ca2+)

Answer 1

The carbonate ion (CO₃²⁻) bonds with calcium ions (Ca²⁺) to form calcium carbonate (CaCO₃), which is the primary component of the shells of many organisms, such as mollusks and corals. Therefore, the correct answer is **Calcium (Ca²+)**.