Amalgam (chemistry) but can be worked with under dry nitrogen. The Hg-Hg distance is around 300 picometres, Hg-K around 358 pm. Phases KHg and KHg are also known; rubidium, strontium and barium undecamercurides are known and isostructural. Sodium amalgam (NaHg) has a different structure, with the mercury atoms forming hexagonal layers, and the sodium atoms a linear chain which fits into the holes in the hexagonal layers, but the potassium atom is too large for this structure to work in KHg. Sodium amalgam is produced as a byproduct of the chloralkali process and used as an important reducing agent in organic and
Dental amalgam controversy condoned the use of dental amalgam. In 1855, Dr. J. Foster Flagg, a professor of dental pathology in Philadelphia, experimented with new mixtures of amalgam. In 1861, he presented his findings to the Pennsylvania Association of Dental Surgeons and, in 1881, he published his book, Plastic and Plastic Fillings (Figure 4). (Amalgam fillings were often called "plastic fillings" at the time.) The inevitable result of this affair was that silver amalgam was proven to be, "an excellent filling material," and expanded dentistry's, "ability to save teeth." Around the same time, John and Charles Tomes in England conducted research on the