(i) Compounds of carbon and hydrogen are called hydrocarbons. e.g. methane, ethane, etc.
(ii) Saturated hydrocarbons contain carbon–carbon single bonds, e.g., methane, ethane. Unsaturated hydrocarbons contain atleast one carbon– carbon double or triple bond, e.g., ethene, ethyne.
(iii) Functional group is an atom or group of atoms joined in a specific manner which is responsible for the characteristics properties of the organic compounds, e.g., OH, —CHO.
