On which principle does the method of fractional distillation work?

Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?
$(i)$ Good thermal conductivity
$(ii)$ Good electrical conductivity
$(iii)$ Ductility
$(iv)$ High melting point

$(i)$ Explain the steps for extraction of copper from its sulphide ore. Write the balanced equations involved in the process.
$(ii)$ What is meant by refining of metals? Draw a diagram of electrolytic refining of copper and name the substances used as cathode, anode, and the electrolyte.

Which non-metal element possesses luster?

$A$ 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?

What is used as a catalyst in the production of sulfuric acid by the contact process?