$A$ black sulphide precipitate when treated with ozone becomes white. The white compound is:

An inorganic compound $(A)$ made of the two most occurring elements in the earth's crust,having a polymeric tetrahedral network structure. With carbon,compound $(A)$ produces a poisonous gas $(B)$ which is the most stable diatomic molecule. Compounds $(A)$ and $(B)$ are:

Which of the following is an amphoteric oxide?

Which gas burns with a blue flame?

Explain the following reactions:
$(a)$ Silicon is heated with methyl chloride at high temperature in the presence of copper.
$(b)$ Silicon dioxide is treated with hydrogen fluoride.
$(c)$ $CO$ is heated with $ZnO$.
$(d)$ Hydrated alumina is treated with aqueous $NaOH$ solution.

When graphite is subjected to an electric arc in the presence of an inert atmosphere,it gives: