Which root name indicates a hydrocarbon chain with ten carbon atoms?

The root name that indicates a hydrocarbon chain with ten carbon atoms is "Dec-." The prefix "Dec-" is derived from the Latin word for ten. In organic chemistry, hydrocarbon chains are named based on the number of carbon atoms they contain, and each prefix corresponds to a specific number of carbons.

For example, other commonly used prefixes include "Meth-" for one carbon, "Eth-" for two, "Prop-" for three, "But-" for four, "Pent-" for five, "Hex-" for six, "Hept-" for seven, "Oct-" for eight, and "Non-" for nine. Following this sequence, "Dec-" is the root name used for a chain containing ten carbon atoms.

In contrast, "Non-" corresponds to nine carbons, "Undec-" corresponds to eleven carbons, and "Hex-" corresponds to six carbons. Therefore, the correct answer reflects the standard naming convention used in organic chemistry for hydrocarbons, making "Dec-" the appropriate choice for a ten-carbon chain.