On heating,lead$(II)$ nitrate gives a brown gas $(A).$ The gas $(A)$ on cooling changes to a colourless solid/liquid $(B).$ $(B)$ on heating with $NO$ changes to a blue solid $(C).$ The oxidation number of nitrogen in solid $(C)$ is :

Nitrogen combines with metals to form

Which of the following statements is correct?

Assertion $(A)$: $P_4O_{10}$ cannot be used to remove moisture from ammonia gas. Reason $(R)$: $P_4O_{10}$ reacts with $NH_3$ gas. The correct answer is:

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

Identify the correct orders from the following with respect to the property associated with:
$A$. $NH_3 > PH_3 > AsH_3 > SbH_3$ - Bond Angle
$B$. $NH_3 > PH_3 > AsH_3 > SbH_3$ - Basic Character
$C$. $PH_3 > AsH_3 > SbH_3 > NH_3$ - Thermal stability
$D$. $SbH_3 > NH_3 > AsH_3 > PH_3$ - Boiling point