I have received several replys now from scientists on what an ion is. Here they are:
From: [email protected] "Hi, a colloid is a particle and in the case of Colloidal Silver should have a charge on it- this kils the micro-organisim. Typical size .05um. An ion is in solution and is just a molecule or atom in size depending on the subatance. As an ion is very very small by comparison it can penetrate the tissues much more easily. Ionic silver is potentially much more toxic than a colloidal particle of silver as it can combine with other ions to produce toxic substances like silver nitate. Hope that helps. Chris Hyslop. Chartered Biologist. Commercial Science." From: [email protected] "Instead of saying 'group of atoms', it should actually say 'molecule'. The earth is not an atom or a molecule, nor is a charged balloon or a colloid. These are both examples of groups of molecules, which should not be included in the definition. So an ion is an atom or molecule deficient in or having excessive electrons relative to the positive charge of the nucleus (or cumulative charge of the nuclei sharing the deficiency/excess)...pretty simple. Protons cannot be exchanged except by nuclear reaction, although the transfer of electron deficiency is the basis for the Bronsted definition of acids as well as the concept of holes in semiconductors. Note that the deficiency or excess in a molecule is usually localized to the atom that results in the lowest formal charge. You can have two or more ionic groups in one molecule due to this localization (zwitterion). Macromolecules such as enzymes and other polymeric species can also be ionic - they are called polyelectrolytes." The "official" definition is at http://www.iupac.org/goldbook/I03158.pdf and says: "ion An atomic or molecular particle having a net electric charge. 1982, 54, 1545" So it seems that in no case can a crystaline particle such as colloidal silver be called an ion even though it may have a charge. Only atoms and molecules can be called an ion. Marshall
