In view of their low ionisation energies,the alkali metals are:

The reactivity of the alkali metal $Na$ with water is made use of in which of the following processes?

Fill in the blanks:
$(1)$ Sodium hydroxide is also known as ......
$(2)$ The reaction of sodium amalgam with water produces ...... and ...... gas.
$(3)$ Sodium hydroxide on reaction with $CO_2$ produces ......
$(4)$ Sodium hydrogen carbonate is known as ......

The lustre of a metal is due to

Why are alkali metals not found in nature?

What is the product formed when sodium nitrate is heated at a temperature of ${800\,^o}C$?