barium metal

Element Ba; Atomic number 56; Atomic weight 137.327; IIA group (the second main group) of alkaline earth elements. Barium is a silvery-white metal. It exists only in minerals containing elemental mixtures in nature. The important compounds are peroxides, chlorides, sulfates, carbonates, nitrates and chlorates. Barium forms alloys and intermetallic chemical compounds with lead, potassium, platinum, magnesium, silicon, zinc, aluminum and mercury. Barium compounds show a close relationship with calcium and strontium compounds, which are also alkaline earth metals. Twenty-five barium isotopes have been identified, with 138Ba being the most abundant, and the rest being unstable isotopes with half-lives ranging from 12.8 days for 140Ba to 12 seconds for 143Ba. Two of these isotopes, 131Ba and 139Ba, are used as radioactive tracers in research.

In the early Middle Ages, alchemists had some knowledge of certain barium ores. Some smooth, oval-shaped barite blocks known as "Bologna stones" were discovered in Bologna, Italy, and attracted the attention of alchemists because these ores would glow for several years after being exposed to light. In 1602, Cassio Laurus described the phosphorescent property of this substance when heated with organic matter. In 1774, Carl Wilhelm Scheele discovered that barite contained a new element that had not been discovered before, but was unable to separate and purify this element, only obtaining its oxide, namely barium oxide. Two years later, Johann Gottlob Ganse also obtained barium oxide in the same research. Barium oxide was first called "barote" by Guyton de Morveau and later renamed "baryta" by Lavoisier. In the same 18th century, British mineralogist William Wollingen noticed a heavy mineral in the lead ore in Cumberland, which is now called toxic barite, and its main component is barium carbonate (BaCO3) and barite, known as barium sulfate (BaSO4). In 1808, Humphry Davy first separated barium as a pure element through electrolysis of molten barium salts. Davy named barium using the name of barite (baryta) combined with the suffix -ium indicating an element, similar to the naming method used for calcium. Robert Bunsen and Augustus Matthesen obtained pure barium by electrolyzing the molten mixture of calcium chloride and ammonium chloride. Barium is the 17th most abundant element in the Earth's crust, accounting for approximately 0.05% of the crust. It is found in magnesite ores, where it is in the form of barium carbonate (BaCO3) and barite, known as barium sulfate (BaSO4). Pure metallic barium does not exist on Earth and exists only in compound form or in minerals and ores. Barite ores have been discovered in Missouri, Arkansas, Georgia, Kentucky, Nevada, California, Canada and Mexico, which are produced by reducing barium oxide (BaO) using aluminum or silicon under high-temperature vacuum conditions. It is also produced by electrolyzing molten barium chloride (BaCl2) at a temperature of approximately 950°C, wher