When a colorless gas is passed through bromine water and it causes decolorization,which gas is it?

Write a note on halide compounds of group-$16$ elements.

Which of the following compounds has the maximum number of oxo groups $(M=O)$?

$V_2O_5$ is useful as a catalyst in:

Among the hydrides of group $16$ elements,the hydride $X$ has the lowest boiling point and the hydride $Y$ has the highest boiling point. $X$ and $Y$ respectively are:

Write the order of thermal stability of the hydrides of Group $16$ elements.