Closed Chain

Open Chain

1. Contains O, S, N atoms other than carbon. 2. O, S, N atoms are called Heteroatoms. 3. May be Aliphatic or Aromatic.

Do not contain any benzene rings. Contains (4n+2)π electrons

Contain one or more benzene rings

1. Benzene or derivatives of benzene. 2. Can contain more than one benzene ring. 3. Properties similar to benzene. 4. Ring contains alternating single and double bonds. 5. Contains (4n+2)π electrons [Huckel's rule] 6. Contains delocalised electrons, for which resonance stabalization is present.

1. Do not contain Benzene structure. 2. Properties similar to aliphatic compounds.

Basic structure is formed by only carbon atoms.

Carbon atoms connected to each other in a ring.

aka: Aliphatic Organic Compound

Compounds having chain of carbon atoms attached by double bonds or triple bonds. Ex: Alkenes, Alkynes

Compounds having chain of carbon atoms attached by single bonds. Ex: Alkanes