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
Amalgam (dentistry) conservative preparation would be beneficial, composite is the recommended restorative material. These situations would include small occlusal restorations, in which amalgam would require the removal of more sound tooth structure, as well as in "enamel sites beyond the height of contour". For cosmetic purposes, composite is preferred when a restoration is required on an immediately visible portion of a tooth. Dental amalgam does not by itself bond to tooth structure. This was recognized as a shortcoming by early practitioners such as Baldwin. He recommended that the prepared cavity be coated with zinc phosphate cement just prior to filling with amalgam,