The compound formed by the reaction of ethanal with semicarbazide contains _________ number of nitrogen atoms.

Number of isomeric aromatic amines with molecular formula $$\mathrm{C}_{8} \mathrm{H}_{11} \mathrm{~N}$$, which can be synthesized by Gabriel Phthalimide synthesis is ____________.

How many of the transformations given below would result in aromatic amines?

The number of sp³ hybridised carbons in an acyclic neutral compound with molecular formula C₄H₅N is ___________.