The element with atomic number $33$ belongs to which group of the periodic table?

Sodium nitrite is reacted with $H_2SO_4$ to form $NaHSO_4$,$HNO_3$,water and $X$. Gold is dissolved in aqua regia to form water,$AuCl_4^{-}$ and $Y$. $X$ and $Y$ are respectively

The pair in which phosphorus atoms have a formal oxidation state of $+3$ is:

The possible oxidation states of $Tl$ are

$NO_2$ is a mixed oxide. This is proved by the fact that it reacts with $H_2O$ and then with $NaOH$ to form:

Which of the following compounds is the most explosive?