Compare the solubility and thermal stability of the given compounds of the alkali metals with those of the alkaline earth metals.
Nitrates

Explanation

Nitrates: (a) The nitrates of alkali metals as well as alkaline earth metals are highly soluble in water. (b) On heating, nitrates of both alkali and alkaline earth metals undergo decomposition. Nitrates of alkali metals decompose to form metallic nitrite and oxygen. On the other hand, nitrates of alkaline earth metals decompose to form the corresponding oxides with evolution of `NO_2 and O_2`.
`2MNO_3 overset(Delta)to2 MNO_2 + O_2 uarr` (M Na, K, Rb, Cs)
`2M(NO_3)_2 overset(Delta)to 2MO + 4NO_2 uarr + O_2 uarr` (M = Be, Mg, Ca, Sr, Ba)
Due to diagonal relationship, lithium nitrates behaves similarly as magnesium nitrate.
`4LiNO_3 overset(Delta)to 2Li_2O + 4NO_2 uarr + O_2uarr`