Which is not a heteroatom?

Tropolone is a benzenoid compound.

Dumas method is a method of estimation of nitrogen.

Which is not used as an absorbent in adsorption chromatography?

What is obtained by thermolysis of azides?

The successive members of a homologous series differ by an unit of which of the following?

Which is the most suitable carrier gas in gas chromatography?

What is the hybridization of singlet carbene?