What does "molecule" mean?

Molecule: (Physics) The smallest part of any substance which possesses the characteristic properties and qualities of that substance, and which can exist alone in a free state.

Additional senses

  1. 2.(Chem.) A group of atoms so united and combined by chemical affinity that they form a complete, integrated whole, being the smallest portion of any particular compound that can exist in a free state; as, a molecule of water consists of two atoms of hydrogen and one of oxygen. Cf. Atom.

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