Naming Compounds
Name ionic, covalent, and acid compounds from their formula, or identify the formula from the name.
Common Questions
How do you name ionic compounds?
Write the cation (metal) name first, then the anion (nonmetal) name with an -ide suffix. For transition metals, include the charge in Roman numerals: iron(III) chloride. For polyatomic ions, use the ion name directly.
How do you name covalent (molecular) compounds?
Use Greek prefixes to indicate the number of each atom: mono- (1), di- (2), tri- (3), tetra- (4), penta- (5), hexa- (6). The first element drops the mono- prefix. The second element gets an -ide suffix. Example: dinitrogen pentoxide.
What is the difference between ionic and covalent naming?
Ionic compounds (metal + nonmetal) do not use Greek prefixes — the charges determine the ratio. Covalent compounds (two nonmetals) use Greek prefixes because multiple ratios are possible.
How do you write a chemical formula from a compound name?
For ionic: determine the ions and their charges, then find the ratio that balances charges. For covalent: the prefixes directly tell you the subscripts. For example, carbon tetrachloride = CCl4.