Generally,non-metals are not lustrous. Which of the following non-metal is lustrous?

Which metal is used in thermometers?

$A$ 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.

Which method,other than the Contact process,is used for the production of sulfuric acid?

$(a)$ An ore on heating in air gives sulphur dioxide gas. Name the method in each metallurgical step that will be required to extract this metal from its ore.
$(b)$ State which of the following reactions will take place or not,giving a suitable reason for each.
$Zn(s) + CuSO_4(aq) \rightarrow ZnSO_4(aq) + Cu(s)$
$Fe(s) + ZnSO_4(aq) \rightarrow FeSO_4(aq) + Zn(s)$

Generally,when metals are treated with mineral acids,hydrogen gas is liberated,but when metals (except $Mn$ and $Mg$) are treated with $HNO_3$,hydrogen is not liberated. Why?