Antimony is a chemical element with the symbol Sb (from Latin: stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl. Metallic antimony was also known, but it was erroneously identified as lead upon its discovery. The earliest known description of the metal in the West was written in 1540 by Vannoccio Biringuccio.
Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the
Boron sulfide
Boron sulfide is the chemical compound with the formula B2S3. This polymeric material that has been of interest as a component of "high-tech" glasses and as a reagent for preparing organosulfur compounds. Like the sulfides of silicon and phosphorus, B2S3
Lev Chugaev
Lev Aleksandrovich Chugaev was a Russian chemist. At the height of his career, he was professor of chemistry at the University of Petersburg, being the successor to Dmitri Mendeleev. He was active in the fields of inorganic chemistry, especially platinum
Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the boron group it has three valence electrons
Lutetium is a chemical element with the symbol Lu and atomic number 71. It is a silvery white metal, which resists corrosion in dry air, but not in moist air. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the
Chromite (compound)
In chemistry the term chromite has been used in two contexts. Under IUPAC naming conventions, chromate(III) is preferred to chromite.For compounds containing an oxyanion of chromium in oxidation state 3 For other compounds of chromium(III) as a means of
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth may occur naturally
Cuprate loosely refers to a material that can be viewed as containing anionic copper complexes. Examples include tetrachloridocuprate ([CuCl4]2−), the superconductor YBa2Cu3O7, and the organocuprates (e.g., dimethylcuprate [Cu(CH3)2]−). The term
Ricardo Bellveser
Ricardo Bellveser Icardo was a Spanish writer and journalist. He died on 29 December 2021, at the age of 73