Metal carbonates

According to the results of heating metal carbonates, the metal carbonatescan be classified into three groups.

I : No decomposition
The four common metal carbonates which do NOT decompose on heating are:
1. sodium carbonate (Na2CO3)
2. potassium carbonate (K2CO3)
3. rubidium carbonate (Rb2CO3)
4. caesium carbonate (Cs2CO3)

II : Decomposition to metal, carbondioxide and oxygen
The three common metal carbonates decompose on heating to give metal,carbon dioxide and oxygen. They are :
1. silver carbonate : 2Ag2CO3(s)­ → 4Ag(s) + 2CO2(g)+ O2(g)
2. mercury(I) carbonate : 2Hg2CO3(s) → 4Hg(l) + 2CO2(g)+ O2(g)
3. mercury(II) carbonate : 2HgCO3(s) → 2Hg(l) + 2CO2(g)+ O2(g)

III : Decomposition to metal oxideand carbonate dioxide
All other common metal carbonates decompose on heating to give metaloxide and carbon dioxide. For example :
CaCO3(s) → CaO(s) + CO2­(g)
CuCO3(s) → CuO(s) + CO2­(g)
...... etc.
Generally speaking, the metal carbonate of a less reactive metal woulddecompose more readily on heating.

yes,such as CaCo3 decompose to CaO and Co2