The correct order of thermal stability of the following metal carbonates isans.

To determine the correct order of thermal stability of metal carbonates, we can analyze the factors that influence their stability, such as the size of the metal cation and the lattice energy of the carbonate.

Factors Affecting Thermal Stability

1. Metal Ion Size: As the size of the metal ion increases, the carbonate's thermal stability generally decreases. Larger cations stabilize the carbonate ion less effectively.
2. Charge Density: Divalent cations (like calcium, barium) are typically more stable than monovalent ones (like sodium, potassium) due to higher charge density.
3. Position in the Periodic Table: Carbonates of alkaline earth metals are generally more thermally stable compared to alkali metals.

General Order of Stability

In general, the thermal stability of carbonates tends to follow this order based on the metal's position in the periodic table:

1. Barium carbonate $\text{BaCO}_3$
2. Strontium carbonate $\text{SrCO}_3$
3. Calcium carbonate $\text{CaCO}_3$
4. Magnesium carbonate $\text{MgCO}_3$
5. Sodium carbonate $\text{Na}_2\text{CO}_3$
6. Potassium carbonate $\text{K}_2\text{CO}_3$

Final Answer

Thus, the correct order of thermal stability of the metal carbonates is:

$\text{BaCO}_3 > \text{SrCO}_3 > \text{CaCO}_3 > \text{MgCO}_3 > \text{Na}_2\text{CO}_3 > \text{K}_2\text{CO}_3$