Final answer:
A molecular compound is a substance made up of molecules formed by two or more nonmetal elements sharing electron pairs. Unlike ionic compounds, they do not involve electron transfer but electron sharing, and are named using specific naming conventions that include numerical prefixes and the suffix -ide for the second element.
Step-by-step explanation:
A molecular compound, also known as a covalent compound, is composed of molecules formed by atoms of two or more different nonmetal elements. These atoms share pairs of electrons through covalent bonds. A characteristic feature of molecular compounds is that they are usually named with the first element first and then the second element by using the stem of the element name plus the suffix -ide. When there are multiple atoms of an element in the molecule, numerical prefixes are used to specify their number.
Common examples of molecular compounds include water (H₂O), with one atom of oxygen and two atoms of hydrogen, and carbon dioxide (CO₂), consisting of one carbon atom and two oxygen atoms. Molecular compounds are distinct from ionic compounds such as sodium chloride (NaCl), which are created by the transfer of electrons from metal atoms to nonmetal atoms, leading to the formation of positively charged cations and negatively charged anions that are held together by electrostatic attraction.