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
Demon in a Bottle he carries in his briefcase, flies out of the plane, and guides it to a safe landing in the ocean. Navy ships approach and soldiers help the passengers to safety, and bring Iron Man to an island base. They tell him the tank was thrown by Namor, who was defending a resident of the island that the soldiers were trying to remove, because the island is used as a toxic waste disposal site. Iron Man confronts and fights Namor, before it's revealed that the soldiers actually belong to the Roxxon Oil Corporation, which is secretly occupying the island to mine