$A$ non-metal $A$ is an important constituent of our food and forms two oxides $B$ and $C$. Oxide $B$ is toxic,whereas $C$ causes global warming.
$(a)$ Identify $A$,$B$,and $C$.
$(b)$ To which Group of the Periodic Table does $A$ belong?

Which of the following properties of $H_2$ (dihydrogen) gas is $NOT$ correct?

Which substance is used for the chemical reduction of metal oxides like chromium and manganese to obtain the metal?

$A, B$ and $C$ are three elements which undergo chemical reactions according to the following equations:
$A_{2}O_{3} + 2B \rightarrow B_{2}O_{3} + 2A$
$3CSO_{4} + 2B \rightarrow B_{2}(SO_{4})_{3} + 3C$
$3CO + 2A \rightarrow A_{2}O_{3} + 3C$
$(a)$ Which element is the most reactive?
$(b)$ Which element is the least reactive?
$(c)$ What is the type of reactions listed above?

What is the chemical formula of rust?

In which solvent is sulphur soluble?