Final answer:
Roman numerals are not used when naming covalent (molecular) compounds.
Step-by-step explanation:
Roman numerals are not used when naming covalent (molecular) compounds. Roman numerals are typically used to indicate the charge on a metal ion in an ionic compound. Covalent compounds are made up of nonmetal atoms that share electrons, so they do not have charges that need to be indicated using Roman numerals.
Learn more about naming covalent (molecular) compounds