The bond energies (in $kJ \ mol^{-1}$) of $N-H$,$P-H$,and $As-H$ are respectively:

When concentrated $H_2SO_4$ is added to dry $KNO_3$,brown fumes evolve. These fumes are

In some of the reactions,thallium resembles aluminium,whereas in others,it resembles group $1$ metals. Support this statement by giving some evidence.

Which among the following group-$15$ elements does $NOT$ react with concentrated sulphuric acid?

$NH_3$ reacts with bleaching powder to give:

Given below are two statements $:$
Statement $I :$ Nitrogen forms oxides with $+1$ to $+5$ oxidation states due to the formation of $p\pi-p\pi$ bond with oxygen.
Statement $II :$ Nitrogen does not form halides with $+5$ oxidation state due to the absence of $d$-orbital in it.
In the light of given statements,choose the correct answer from the options given below.