Barium is a chemical element with symbol Ba and atomic number 56. It is one of the alkaline earth metal elements, belonging to IIA group elements in the periodic table. Barium is a soft silvery white metal with ductility and plasticity. Its density is about 3.594 g/cm? , melting point is 727℃, boiling point is 1870℃.
Barium is very active in chemistry and can react with many nonmetallic and metallic elements. It reacts with oxygen to form oxide, with halogen to form halide, and with sulfur to form sulfide. Barium can also react with water to produce barium hydroxide and hydrogen.
In nature, barium is mainly barite (BaSO? ) exists in the form of. Barite is an important mineral resource, which is widely used in oil and gas drilling, coatings, plastics, rubber, paper making and other fields. Barium compounds are also used to make fireworks, phosphors, pigments, glass and so on.
Barium compounds have certain toxicity, especially soluble barium salts such as barium chloride and barium nitrate, which are harmful to human body. Therefore, care should be taken when touching or using barium and its compounds, and relevant safety operation procedures should be observed.
Chemical use of elemental barium;
1, phosphor and cathode ray tube: barium sulfide (BaS) and oxide (BaO) play a key role in phosphor and cathode ray tube. These materials can emit bright green light when excited by electron beams or ultraviolet rays. They are widely used in the displays of televisions, computers and mobile phones, as well as various lighting devices.
2. Glass and ceramic products: barium compounds such as barite (BaSO? ) and barium carbonate (BaCO? ) plays an important role in the manufacture of glass and ceramics. As an additive, it can increase the transparency and refractive index of glass and ceramics, and at the same time improve the wear resistance and impact resistance of products.
3, barium meal contrast agent: in the medical field, barium sulfate (BaSO? ) is often used as X-ray contrast agent, commonly known as "barium meal". When a patient swallows a liquid or paste containing barium sulfate, the doctor can observe the digestive tract through X-ray examination. Because barium sulfate is insoluble in water and gastric acid and harmless to human body, it is widely used in the diagnosis of gastrointestinal diseases.