$Na_2CO_3 \xrightarrow{\Delta} A$,'$A$' is

As compared to lithium,sodium reacts quickly with water because

$(a)$ Describe the chemical properties of alkali metals with air,water,dihydrogen,and halogens.
$(b)$ Explain the reduction potential of alkali metal elements.
$(c)$ Which type of solutions are formed on the reaction of alkali metals with liquid ammonia?

Which of the following substances will react with concentrated $H_2SO_4$?

When sodium metal is dissolved in liquid ammonia,a blue-coloured solution is formed. The blue colour is due to:

Which of the following salts is known as washing soda?