Nitrogen dioxide cannot be obtained by heating:

$Pb + \text{Dil. } HNO_3 \xrightarrow{\text{Warm}} P + Q\uparrow + H_2O$
Incorrect statement for $Q$ is

Discuss the variations in atomic and ionic radii of elements,the trends in ionisation enthalpies and electronegativity of group-$15$ elements.

Nitrous oxide is known as

In the Birkeland-Eyde process,the raw material used is:

Thallium shows different oxidation states because