The incorrect statement$(s)$ about $O_3$ is (are):

Which one of the following is most acidic?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$ : Both rhombic and monoclinic sulphur exist as $S_8$ while oxygen exists as $O_2$.
Reason $(R)$ : Oxygen forms $p \pi-p \pi$ multiple bonds with itself and other elements having small size and high electronegativity like $C, N$,which is not possible for sulphur.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which of the following oxyacids of sulphur contains both $S=S$ and $S=O$ bonds?

Describe the manufacture of $H_2SO_4$ by the contact process.

Group $16$ elements are also called: