What is formed when sodium bicarbonate is heated strongly?

Assertion : $K$,$Rb$ and $Cs$ (all belonging to group $1$) can also form superoxides.
Reason : The ionic radii of $K$,$Rb$ and $Cs$ show the following trend $Cs^{+} < Rb^{+} < K^{+}$.

Crude sodium chloride obtained by crystallisation of brine solution does not contain

What are the metal ions present in carnallite?

Match List-$I$ with List-$II$ :

List-$I$	List-$II$
$(a)$ $Li$	$(i)$ Poor water solubility of $I^{-}$ salt
$(b)$ $Na$	$(ii)$ Most abundant element in cell fluid
$(c)$ $K$	$(iii)$ Bicarbonate salt used in fire extinguisher
$(d)$ $Cs$	$(iv)$ Carbonate salt decomposes easily on heating

Choose the correct answer from the options given below :

The correct order of solubility for the given compounds is: