Manganese(II) sulfide Manganese(II) sulfide Manganese(II) sulfide is a chemical compound of manganese and sulfur. It occurs in nature as the mineral alabandite (isometric), rambergite (hexagonal), and recently found browneite (isometric, with sphalerite-type structure, extremely rare, known only from a meteorite). Manganese(II) sulfide can be prepared by reacting a manganese(II) salt (such as manganese(II) chloride) with ammonium sulfide: The crystal structure of manganese(II) sulfide is similar to that of sodium chloride. The pink color of MnS likely results from poor coupling between the lowest energy unoccupied Mn orbitals, resulting in discrete states rather than a delocalized band. Thus the lowest energy band-to-band electronic
Hazard symbol carry a significant health risk (biohazards), including viral samples and used hypodermic needles (see sharps waste). The biohazard symbol was developed by the Dow Chemical Company in 1966 for their containment products. According to Charles Baldwin, an environmental-health engineer who contributed to its development: "We wanted something that was memorable but meaningless, so we could educate people as to what it means." In an article in "Science" in 1967, the symbol was presented as the new standard for all biological hazards ("biohazards"). The article explained that over 40 symbols were drawn up by Dow artists, and all of the symbols