Which non-metal element is used in the vulcanization of rubber?

$A$ 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?

Define alloys. List the properties of alloys that make them useful over pure metals. Explain this fact with suitable examples.

What is the chemical formula of oleum?

Give two examples each of metals that are good conductors and poor conductors of heat,respectively.

Which one of the following metals does not react with cold as well as hot water?