The thermal stability of alkaline earth metal carbonates () increases down the group from to . Which — s Block Elements Chemistry Question

💡 Solution & Explanation

Thermal stability of polyatomic anions (like carbonates) increases with a decrease in the polarizing power of the cation. As we move down Group 2, the ionic size increases, which decreases its polarizing power. This leads to less distortion (polarization) of the electron cloud of the large $CO_3^{2-}$ anion, making the metal carbonate more stable towards heat.