Answer – There are primarily ten types of numerical prefixes used for the systematic naming of binary molecular compounds.
Explanation:
In chemistry, naming prefixes are specific syllables or words added to the names of chemical compounds; they indicate the number of atoms or groups of atoms present in that compound. IUPAC (International Union of Pure and Applied Chemistry) is the globally recognized authority for chemical nomenclature and terminology. Its system of nomenclature has three essential parts: the root word, prefix, and suffix.
A prefix appears before the root word (e.g., the number of carbon atoms present in a parent chain) and denotes substituents (i.e., functional groups or atoms other than hydrogen) attached to the parent chain. These prefixes are derived from Greek words. There are ten types of numerical prefixes used for binary (two-element) molecular compounds:
| Naming Prefix | Number of Atoms | Example |
| Mono– (meaning “single” or “alone”) | Indicates one atom or group of atoms | Carbon monoxide (CO) |
| Di- (meaning “twice” or “double”) | Indicates two atoms or groups of atoms | Carbon dioxide (CO2) |
| Tri- (meaning “three”) | Indicates three atoms or groups of atoms | Chlorine trifluoride (ClF3) |
| Tetra- (meaning “four”) | Indicates four atoms or groups of atoms | Carbon Tetrachloride (CCl4) |
| Penta- (meaning “five”) | Indicates five atoms or groups of atoms | Pentane (C5H12) |
| Hexa- (meaning “six”) | Indicates six atoms or groups of atoms | Hexane (C6H14) |
| Hepta- (meaning “seven”) | Indicates seven atoms or groups of atoms | Heptane (C7H16) |
| Octa- (meaning “eight”) | Indicates eight atoms or groups of atoms | Octane (C8H18) |
| Nona- (meaning “nine”) | Indicates nine atoms or groups of atoms | Nonane (C9H20) |
| Deca- (meaning “ten”) | Indicates ten atoms or groups of atoms | Decane (C10H22) |
