#molecule  (physics and chemistry) the simplest structural unit of an element or compound
  supertype:  building_block__unit  a single undivided natural entity occurring in the composition of something else; "units of nucleic acids"
  subtype:  dipole_molecule  protein_molecule  coenzyme  macromolecule
  part:  chemical_chain__chain  a series of linked atoms (generally in an organic molecule)
  part:  atom  (physics and chemistry) the smallest component of an element having the chemical properties of the element
     part:  elementary_particle__fundamental_particle__fundamentalparticle__subatomicparticle  a particle that is less complex than an atom; regarded as constituents of all matter
     part:  nucleus__nucleu  the positively charged dense center of an atom
        part:  nucleon  a constituent (proton or neutron) of an atomic nucleus
  part:  chemical_group__group__radical  (chemistry) two or more atoms bound together as a single unit and forming part of a molecule

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