Lanthanide
Lanthanide, lanthanid
Definition: Elements 57 to 71 in the periodic table. The general term for 15 elements from lanthanum to lutetium. Expressed as Ln. The valence electron configuration is 4f0~145d0~26s2, belonging to the internal transition element; Lanthanum without 4f electrons is also excluded from the lanthanide system.
Discipline: Chemistry_ Inorganic chemistry_ Elements and Inorganic chemistry
Related terms: hydrogen sponge Nickel–metal hydride battery
The group of 15 similar elements between lanthanum and lutetium in the periodic table is called Lanthanide. Lanthanum is the first element in Lanthanide, with Chemical symbol La and Atomic number 57. Lanthanum is a soft (can be cut directly with a knife), ductile, and silver white metal that gradually loses its luster when exposed to air. Although lanthanum is classified as a rare earth element, its element content in the crust ranks 28th, almost three times that of lead. Lanthanum has no special toxicity to the human body, but it has some antibacterial activity.
Lanthanum compounds have various uses and are widely used in catalysts, glass additives, carbon arc lamps in studio photography lamps or projectors, ignition components in lighters and torches, cathode ray tubes, scintillators, GTAW electrodes, and other products.
One of the materials used for Nickel–metal hydride battery anode is La (Ni3.6Mn0.4Al0.3Co0.7). Because of the high cost of removing other Lanthanide, pure lanthanum will be replaced by mixed rare earth metals containing more than 50% lanthanum. Hydrogen sponge alloys contain lanthanum, which can store up to 400 times its own volume of hydrogen during reversible adsorption and release heat energy. Therefore, hydrogen sponge alloys can be used in energy-saving systems. Lanthanum oxide and Lanthanum hexaboride are used as hot cathode materials in electron vacuum tubes. The crystal of Lanthanum hexaboride is a high brightness and long-life hot electron emission source for electron microscopes and Hall-effect thruster.
Lanthanum trifluoride is used as fluorescent lamp coating, mixed with Europium(III) fluoride, and used as crystal film of fluoride ion selective electrode. Lanthanum trifluoride is also an important part of a heavy fluoride glass called ZBLAN. It has excellent transmittance in the infrared range and is widely used in optical fiber communication systems. Cerium doped Lanthanum(III) bromide and Lanthanum(III) chloride have the properties of high light output, optimal energy resolution and fast response. They are inorganic Scintillator materials, which are widely used commercially for neutrons and γ A detector for radiation. The glass added with Lanthanum oxide has high refractive index and low dispersion, and can also improve the alkali resistance of the glass. It can be used to make special optical glass, such as infrared absorption glass, for cameras and telescope lenses. Adding a small amount of lanthanum to steel can improve its impact resistance and ductility, while adding lanthanum to molybdenum can reduce its hardness and sensitivity to temperature changes. Lanthanum and various compounds of other rare earth elements (oxides, chlorides, etc.) are components of various catalysts, such as cracking reaction catalysts.
Lanthanum carbonate is approved as a drug. When hyperphosphatemia occurs in renal failure, taking Lanthanum carbonate can regulate the phosphate in serum to reach the target level. Lanthanum modified bentonite can remove phosphate in water to avoid Eutrophication of lake water. Many purified swimming pool products contain a small amount of lanthanum, which is also to remove phosphate and reduce algae growth. Like Horseradish peroxidase, lanthanum is used as an electron dense tracer in molecular biology.
Post time: Aug-01-2023