Which among the following compounds does not act as a reducing agent?

Consider the following statements in respect of oxides of sulphur.
$(1)$ In gas phase $SO_2$ molecule is $V$-shaped.
$(2)$ In gas phase $SO_3$ molecule is planar.
$(3)$ $\gamma-SO_3$ is a cyclic trimer.
Which of the above statements are correct?

Which of the following is formed when $SO_3$ is absorbed by concentrated $H_2SO_4$?

$H_2S$ is less acidic than $H_2Te$. Why?

Identify the correct statements from the following.
$(i)$ Oxygen shows $-2, -1, +1$ and $+2$ oxidation states.
$(ii)$ The thermal stability of $H_2O, H_2S$ and $H_2Se$ follows the order $H_2O < H_2S < H_2Se$.
$(iii)$ The reducing nature of $H_2S, H_2Se$ and $H_2Te$ follows the order $H_2S < H_2Se < H_2Te$.

Which of the following is not a chalcogen?