Which acid is formed when sulfur dioxide reacts with water?

Which non-metal element is found in a gaseous state at room temperature?

Out of the two metals $P$ and $Q$, $P$ is less reactive than $Q$. Suggest an activity to arrange these metals in the order of their decreasing reactivity. Support your answer with a suitable chemical equation.

From amongst the metals sodium,calcium,aluminium,copper and magnesium,name the metal:
$(i)$ which reacts with water only on boiling,and
$(ii)$ another which does not react even with steam.

State reasons for the following:
$(i)$ Metals are good conductors of heat.
$(ii)$ Addition of some silver to pure gold for making ornaments.
$(iii)$ Inability of non-metals to displace hydrogen from dilute sulphuric acid.

$A$ solution of $CuSO_{4}$ was kept in an iron pot. After a few days,the iron pot was found to have a number of holes in it. Explain the reason in terms of reactivity. Write the equation of the reaction involved.