Period 6 element devices though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alcohol-filled, galinstan-filled, digital, or thermistor-based instruments. It remains in use in scientific research applications and in amalgam material for dental restoration. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave ultraviolet light which then causes the phosphor to fluoresce, making visible light. Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray other metal resembles tin but discolors when exposed to air. The
Bomb disposal Bomb disposal Bomb disposal is the process by which hazardous explosive devices are rendered safe. "Bomb disposal" is an all-encompassing term to describe the separate, but interrelated functions in the military fields of explosive ordnance disposal (EOD) and improvised explosive device disposal (IEDD), and the public safety roles of public safety bomb disposal (PSBD) and the bomb squad. "Bomb disposal" does not encompass the remediation of soils polluted with explosive materials. The first professional civilian bomb squad was established by Sir Vivian Dering Majendie. As a Major in the Royal Artillery, Majendie investigated an explosion on 2 October 1874 in