THERMAL Stability of alkaline metal carbonates and Alkaline earth metal carbonates

Group 2 -BeCO3<MgCO3<CaCO3 <SrCO3<BaCO3

Group 1 -Li2CO3<Na2CO3<KCO3<Rb2CO3<Cs2CO3

Li2CO3 Decomposes easily on heating to give CO2

Li2CO3 → Li2O + CO2

All other Group 1 elements can be easily decomposed.

GROUP 2 elements can be decomposed : Only more heat is required as we move down

Hope This Helps