The electronic configuration of chalcogens in their outermost orbit is:

The final acid obtained during the manufacture of $H_2SO_4$ by the contact process is

Assertion : Reaction of $SO_2$ and $H_2S$ in the presence of $Fe_2O_3$ catalyst gives elemental sulphur.
Reason : $SO_2$ is a reducing agent.

Which of the following dinegative anions is quite common?

Indicate the products $(X)$ and $(Y)$ in the following reactions:
$Na_{2}S + nS (n=1-8) \rightarrow (X)$
$Na_{2}SO_{3} + S \rightarrow (Y)$

The colour of liquid $O_2$ is