Phosphorous and phosphoric acids are, respectively, . . . . . . acids.

Which of the following is the incorrect order?

Ammonia is liberated in the reaction of

The $15^{th}$ group of the periodic table contains elements $N, P, As, Sb,$ and $Bi$. As we move from $N$ to $Bi$,how do the oxides with the general formula $E_2O_3$ behave?

Why does nitrogen show catenation properties less than phosphorus?

Explain the chemical behaviour of oxoacids of phosphorus.