Chemistry, Physics. the smallest physical unit of an element or compound, consisting of one or more like atoms in an element and two or more different atoms in a compound.
Chemistry. a quantity of a substance, the weight of which, measured in any chosen unit, is numerically equal to the molecular weight; gram molecule.
1794, "extremely minute particle," from French molécule (1670s), from Modern Latin molecula, diminutive of Latin moles "mass, barrier" (see mole (3)). A vague meaning at first; the vogue for the word (used until late 18c. only in Latin form) can be traced to the philosophy of Descartes. First used of Modern Latin molecula in modern scientific sense by Amedeo Avogadro (1811).
The smallest particle into which an element or a compound can be divided without changing its chemical and physical properties; a group of atoms that is held together chemically.
A group of two or more atoms linked together by sharing electrons in a chemical bond. Molecules are the fundamental components of chemical compounds and are the smallest part of a compound that can participate in a chemical reaction.
