When Conc. $H_2SO_4$ is added to charcoal :-

Which of the following oxides of sulfur contains a sulfur-sulfur $(S-S)$ bond?

Which of the following statements is correct?

Which of the following statements regarding sulphur is not correct?

Assertion : Dinegative anion of oxygen $(O^{2-})$ is quite common but dinegative anion of sulphur $(S^{2-})$ is less common.
Reason : Covalency of oxygen is two.

What are the values of electron gain enthalpy in groups $16$ and $17$? How do they change?