Which of the following prefixes indicates a total of three atoms in a chemical compound?

The prefix "tri" is used in chemical nomenclature to indicate the presence of three atoms of a given element in a compound. For instance, in compounds like trichloride (Cl₃), the "tri-" prefix clearly denotes that there are three chlorine atoms bonded to another element.

In contrast, the other prefixes mentioned serve different purposes: "di" signifies two atoms, "quart" is not a standard prefix in chemistry, and "hex" refers to six atoms. Hence, "tri" stands out as the only prefix that correctly indicates a total of three atoms in a chemical compound.