$NO_2$ gas is

State the oxoacids of phosphorus with their formula,methods of preparation,and the presence of characteristic bonds in their structure.

Which of the following compounds does not give an oxyacid of the central atom on hydrolysis?

In which of the following reactions,$NO_2$ is not liberated?

Nitrogen exists as $N_2$,whereas phosphorus exists as $P_4$. This is because ..........

Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form oxides of nitrogen because .......................