| a series of atoms linked in a chain not joined together at its ends, and so represented in its structural formula. |
| open chain n. An arrangement of atoms that does not form a ring, as in silicon compounds and various carbon compounds, such as aliphatic hydrocarbons. |
| open chain
An arrangement of atoms of the same type that does not form a ring. Aliphatic compounds, such as ethane and isopropyl alcohol, are open-chain compounds. |