Organic Chemistry - Fundamentals of organic chemistry

A homologous series is a series of compounds with the same functional group and general formula. Members show a gradation in physical properties, such as boiling point, which increases with the number of carbon atoms due to increased London dispersion forces.

Functional groups are specific atoms or groups of atoms within a molecule that determine its chemical reactivity. Examples include the hydroxyl group ($-OH$) in alcohols and the carboxyl group ($-COOH$) in carboxylic acids.

Structural isomers are compounds that have the same molecular formula but different structural arrangements of atoms (e.g., $CH_3CH_2CH_2CH_3$ and $CH_3CH(CH_3)CH_3$).

Saturated hydrocarbons (alkanes) contain only single $C-C$ bonds, while unsaturated hydrocarbons (alkenes, alkynes) contain double ($C=C$) or triple ($C\equiv C$) carbon-carbon bonds.

Benzene ($C_6H_6$) is an aromatic hydrocarbon. It exists as a planar hexagonal ring with delocalized $\pi$ electrons, which provides extra stability compared to theoretical cyclic alkenes.

Carbon atoms are classified as primary ($1^\circ$), secondary ($2^\circ$), or tertiary ($3^\circ$) based on how many other carbon atoms are bonded to the carbon atom attached to the functional group.