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

What is the correct order of acidic character for the given oxides?

Assertion $(A)$: In group $15$ elements,nitrogen does not form pentahalides.
Reason $(R)$: Nitrogen can exhibit $+5$ oxidation state.
The correct option among the following is:

Which of the following has the highest boiling point?

$A$ pungent smelling gas $A$ gives dense white fumes with conc. $HCl$. When $A$ reacts with an alkaline solution of a colourless reagent $B$,a reddish-brown precipitate $C$ is formed. The compounds $A, B, C$ respectively are:

$A$ soft heavy metal melts at $30\ ^oC$ and is used in making heat-sensitive thermometers. The metal is: