Which one of the following alkali metals gives hydrated salts?

Identify the correct order of standard enthalpy of formation of sodium halides.

What is Soda ash?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Lithium salts are hydrated.
Reason $(R):$ Lithium has higher polarising power than other alkali metal group members.
In the light of the above statements,choose the most appropriate answer from the options given below:

Thermal decomposition of sodium nitrate at temperatures above $800\,^oC$ yields ..........

What are the metal ions present in carnallite?