(N/A) Hydrocarbons are classified into three main categories based on their structure and bonding:
$1$. Saturated Hydrocarbons: These contain only carbon-carbon single bonds $(C-C)$. All carbon atoms are $sp^3$ hybridized. Examples include alkanes like methane $(CH_4)$,ethane $(C_2H_6)$,and cycloalkanes like methylcyclopropane.
$2$. Unsaturated Hydrocarbons: These contain at least one carbon-carbon double bond $(C=C)$ or triple bond $(C \equiv C)$. The carbon atoms involved in multiple bonds are $sp^2$ or $sp$ hybridized. Examples include alkenes (e.g.,ethene) and alkynes (e.g.,ethyne).
$3$. Aromatic Hydrocarbons: These are cyclic compounds that follow $H$ückel's rule (planar,cyclic,conjugated system with $4n+2$ $\pi$ electrons). All carbon atoms in the ring are typically $sp^2$ hybridized. Examples include benzene,toluene,and naphthalene.