The formula for a carbonate ion is CO3(2-) according to Los Angeles City College. This ion is a strong base, so it attracts protons in aqueous solutions.

Carbonate bonds to positively charged metal ions. This usually results in the formation of an insoluble compound. Some of the most well-known carbonate compounds are sodium carbonate and calcium carbonate.

Carbonate is useful in many different industries. One of its most practical applications is softening hard water. Bicarbonates are sometimes used to neutralize acid spills in laboratories. This ion is also used to produce medications. Lithium carbonate, for example, is used to treat manic depression.

All the alkali metals, except lithium, produce thermally stable compounds when they react with carbonate ions.