This formula is Sn(CO3)2.
Formula: Sn3(PO4)4
Sn(ClO4)4
Rb2CO3 for rubidium carbonate
The formula of sodium [note correct spelling] carbonate is Na2CO3.
A carbon carbonate don't exist. Thew ion carbonate is CO3-; a metal carbonate has the chemical formula MeCO3.
The chemical formula of calcium carbonate is CaCO3.
The formula for Vanadium (IV) carbonate is V(CO3)2.
The formula for dinitrogen carbonate is N2CO3.
The formula for manganese carbonate is MnCO3.
Ammonia and carbonate do not make a formula, they make a compound which is ammonium carbonate,
Formula: ZnCO3
The formula for plumbic carbonate is PbCO3. So there is one carbonate ion (CO3)-2 in the unit formula for PbCO3. A more modern name for this compound is lead (II) carbonate.