The thermal stability increases down the group.

BeCO$_3$ is more thermally stable than MgCO$_3$ due to the high polarizing power of Be$^{2+}$

BaCO$_3$ decomposes at a much higher temperature than MgCO$_3$.

The decomposition of these carbonates yields the corresponding metal oxide and CO$_2$.

As a purgative

In bleaching silk

In drying gases and alcohol

In dyeing cotton

${\rm{Ca}}{{\rm{C}}_2}$

${\rm{ZnC}}$

${\rm{SiC}}$

${\rm{TiC}}$

$\rm{MgH_2 > CaH_2 > SrH_2}$

$\rm{SrH_2 > CaH_2 > MgH_2}$

$\rm{CaH_2 > SrH_2 > MgH_2}$

$\rm{SrH_2 > MgH_2 > CaH_2}$

${\rm{Mg}}$

${\rm{P}}$

${{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}$

${\rm{CaC}}{{\rm{l}}_2}$

Sodium atoms

Solvated electrons

${\rm{NaOH}}$

Sodium amide

${\rm{AlC}}{{\rm{l}}_3}$

${\rm{BeC}}{{\rm{l}}_2}$

${{\rm{B}}_2}{{\rm{H}}_6}$

${\rm{SiC}}$

Sodium atoms

Solvated electrons

${\rm{NaOH}}$

Sodium amide

Magnesium and sodium

Magnesium and copper

Magnesium and barium

Magnesium and potassium

Dimer and Linear, respectively

Chain in both

Chain and dimer, respectively

Linear in both

Heavy lead

Magnesium oxide

Zinc oxide

Sodium sulphate