Molecule 11 : Chemistry and Chemical Disasters. The smallest particle of any substance that can exist free and still exhibit all the properties of the original substance. (COGWE, SSWID)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}