Which prefix indicates the presence of a carbon chain with a length of one carbon atom?

The prefix that indicates the presence of a carbon chain with a length of one carbon atom is "meth-." In organic chemistry, the prefix "meth-" is used to denote compounds that have a single carbon atom, such as methane (CH₄), which is the simplest hydrocarbon.

Knowing the prefixes is essential in naming organic compounds, as they help identify the number of carbon atoms present in the longest continuous chain. For example, "eth-" refers to a two-carbon chain, while "prop-" and "but-" refer to three and four carbon atoms, respectively. By understanding these fundamental prefixes, you can accurately recognize and name a variety of organic compounds based on their structure.