Period 6 element form, as an X-ray radiocontrast agent for imaging the human gastrointestinal tract. Soluble barium compounds are poisonous due to release of the soluble barium ion, and have been used as rodenticides. New uses for barium continue to be sought. It is a component of some "high temperature" YBCOsuperconductors, and electroceramics. The lanthanide or lanthanoid (IUPAC nomenclature) series comprises the fifteen metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium. These fifteen elements, along with the chemically similar elements scandium and yttrium, are often collectively known as the rare earth elements. The informal chemical symbol Ln is
Sterling silver artisan, his success partly due to this strategic investment. Although he is celebrated for his beautiful hollowware, Revere made his fortune primarily on low-end goods produced by the mill, such as flatware. With the onset of the first Industrial Revolution, silversmithing declined as an artistic occupation. From about 1840 to 1940 in the United States and Europe, sterling silver cutlery (US: 'flatware') became "de rigueur" when setting a proper table. There was a marked increase in the number of silver companies that emerged during that period. The height of the silver craze was during the 50-year period from 1870 to