free molecule

free molecule

[¦frē ′mäl·ə‚kyül]
(physical chemistry)
A molecule, as in a gas, whose properties, such as spectrum and magnetic moment, are not affected by other atoms, ions, and molecules nearby.
References in periodicals archive ?
In the first stage it fills the microscopic hills and valleys in the substrate and attaches to free molecules at the surface.
Thus, they assume the existence of association complexes formed of single molecules linked by hydrogen bonding or by any other strong specific interaction and the nonassociated species or the free molecules of solvents, proposing the association equilibria theory (AE).
One reason may be that the molecules exist as ions, solid grains, or molecules trapped on grains instead of as free molecules.