What is the aromatic compound?

the criteria for the compound to be aromatic are

Aromatic compounds, also known asarenesoraromatics, arechemicalcompounds that containconjugatedplanar ring systems with delocalisedpi electronclouds instead of discrete alternatingsingleanddouble bonds. Typical aromatic compounds arebenzeneandtoluene. They should satisfyHückel's rule.Inorganic chemistry,Hückel's ruleestimates whether aplanarringmoleculewill havearomaticproperties.Acyclicring molecule followsHückel's rulewhen the number of itsπ-electronsequals 4n+2 wherenis zero or any positiveinteger, although clearcut examples are really only established for values ofn= 0 up to aboutn= 6

Aromatic compounds are more stable than theoretically predicted by alkene hydrogenation data; the "extra" stability is due to the delocalized cloud of electrons, called resonance energy. Criteria for simple aromatics are:

the molecule must follow Huckel's rule, having 4n+2 electrons in the delocalized, conjugated p-orbital cloud;
the molecule must be able to be planar;
the molecule must be cyclic; and,
every atom in the ring must be able to participate in delocalizing the electrons by having a p-orbital or an unshared pair of electrons.