An element $X$ belongs to group $16$ and $5^{th}$ period. Its atomic number is

Why are the elements of group $16$,excluding polonium,called chalcogens?

Which of the statements given below is incorrect?

Given below are two statements:
Statement $I$: The boiling point of hydrides of Group $16$ elements follows the order
$H_2O > H_2Te > H_2Se > H_2S$.
Statement $II$: On the basis of molecular mass,$H_2O$ is expected to have a lower boiling point than the other members of the group,but due to the presence of extensive $H$-bonding in $H_2O$,it has a higher boiling point.
In the light of the above statements,choose the correct answer from the options given below:

$SO_2$ can be converted into $SO_3$ with the help of:

Given below are two statements:
Statement $I$: The boiling points of the following hydrides of group $16$ elements increase in the order: $H_2O < H_2S < H_2Se < H_2Te$.
Statement $II$: The boiling points of these hydrides increase with an increase in molar mass.
In the light of the above statements,choose the most appropriate answer from the options given below: