What prefix indicates a carbon chain with six carbon atoms?

The prefix that indicates a carbon chain with six carbon atoms is "Hex-". This stem comes from the Greek word "hex", which means six. In organic chemistry, prefixes are used to denote the number of carbon atoms in a hydrocarbon chain.

For example, "pent-" refers to five carbon atoms, "oct-" refers to eight carbon atoms, and "hept-" refers to seven carbon atoms. Thus, when you encounter "hex-", it indicates that the compound or carbon chain consists of six carbon atoms. This terminology allows chemists to quickly understand the structure and size of various organic molecules.