Vismut

Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal, a member of the p-block, and is chemically similar to its lighter congeners in group 15, arsenic and antimony. Bismuth is a relatively rare element, typically found in ores such as bismuthinite and bismite. It is also a byproduct of lead, copper, tin, silver, and gold mining.

Pure bismuth is a silvery-white metal with a distinct reddish tinge. It is brittle and has a very low thermal conductivity. Bismuth has a high electrical resistance. One of its most striking properties is its tendency to form iridescent, hopper-shaped crystals. This iridescence is due to the formation of a thin oxide layer on the surface.

Historically, bismuth was confused with other metals, including lead and tin. It was recognized as a distinct element in the 15th century. The name "bismuth" is thought to derive from the German words "wismut" or "wesemut," possibly meaning "white mass."

Bismuth compounds are used in a variety of applications. Bismuth subsalicylate is a common active ingredient in over-the-counter medications for treating diarrhea and indigestion. Bismuth oxychloride is used in cosmetics as a pigment and pearlescent agent. Bismuth alloys are used in solders, fire sprinklers, and low-melting point alloys. Unlike lead, bismuth is considered to be non-toxic, making it a desirable substitute in many applications.