Chemical State

A chemical state can exist on or inside the surface of a solid state material and can often, but not always, be isolated or separated from the other chemical species found on the surface of that material. Surface scientists, spectroscopists, chemical analysts, and material scientists frequently describe the chemical nature of the chemical species, functional group, anion, or cation detected on the surface and near the surface of a solid state material as its chemical state.

To understand how a chemical state differs from an oxidation state, anion, or cation, we compare sodium fluoride (NaF) to poly-tetrafluoro-ethylene (PTFE, Teflon TM). Both contain fluorine, the most electronegative element, but only NaF dissolves in water to form separate ions, Na+ and F-. The electronegativity of the fluorine strongly polarizes the electron density that exists between the carbon, C, and the fluorine, F, but not enough to produce ions which would allow it to dissolve in the water. The carbon and fluorine in Teflon (PTFE) both have a zero (0) electronic charge since they form a covalent bond, but few scientists describe those elements as has having a zero (0) oxidation state. On the other hand, many elements, in their pure form, are often described as existing with a zero oxidation state. This is one of those quirks of nomenclature that have survived over the years.