Silicon (called silicon in Taiwan and Hong Kong) is a chemical element. Its chemical symbol is Si, formerly known as silicon. The atomic number is 14 and the relative atomic mass is 28.09. There are two kinds of allotropes, amorphous and crystalline. Allotropes include amorphous silicon and crystalline silicon.
Silicon (called silicon in Taiwan and Hong Kong) is a chemical element. Its chemical symbol is Si, formerly known as silicon. The atomic number is 14 and the relative atomic mass is 28.09. There are two kinds of allotropes, amorphous and crystalline. Allotropes include amorphous silicon and crystalline silicon. A metal-like element belonging to the IVA group on the periodic table. crystalline silicon is steel gray, amorphous silicon is black, density 2.4g/cm3, melting point 1420°C, boiling point 2355°C, crystalline silicon is an atomic crystal, hard and shiny, with semiconductor properties. The chemical properties of silicon are relatively active. It can combine with oxygen and other elements at high temperatures. It is insoluble in water, nitric acid and hydrochloric acid, but soluble in hydrofluoric acid and lye. It is used to make alloys such as ferrosilicon, silicon steel, etc., single crystals Silicon is an important semiconductor material used in the manufacture of high-power transistors, rectifiers, solar cells, etc. Silicon is widely distributed in nature. The earth's crust contains about 27.6%, mainly in the form of silicon dioxide and silicate. Crystalline silicon is dark blue, very brittle, and is a typical semiconductor. The chemical properties are very stable. At room temperature, it is difficult to react with other substances except hydrogen fluoride.
Product Usage
① High-purity single crystal silicon is an important semiconductor material. Doping a trace amount of group IIIA elements into monocrystalline silicon to form a p-type silicon semiconductor; doping a trace amount of group VA elements to form n-type and p-type semiconductors combined together to form a solar cell that converts radiant energy For electrical energy. It is a promising material in the development of energy.
②Cermets, important materials for astronautics. Ceramic and metal are mixed and sintered to make a metal-ceramic composite material, which is resistant to high temperature, rich in toughness, and can be cut. It not only inherits the respective advantages of metal and ceramic, but also makes up for the inherent defects of the two. The space shuttle "Columbia", which can be used in military weapons manufacturing, can withstand the high temperature generated by friction when it travels through dense atmosphere at high speed, relying on its shell made of 31,000 silicon tiles.
③Optical fiber communication, a new modern communication method. Pure silica is used to draw high-transparency glass fiber. The laser is transmitted forward through countless total reflections in the path of the glass fiber, instead of bulky cables. The optical fiber communication capacity is high. A glass fiber as thin as a hair can transmit 256 telephones at the same time. It is not afraid of electric and magnetic interference, is not afraid of eavesdropping, and has a high degree of confidentiality. Optical fiber communication will revolutionize human life in the 21st century.
④ Silicon compound with excellent performance. For example, silicone plastic is an excellent waterproof coating material. Spraying silicon on the four walls of the subway can solve the water seepage problem once and for all. Coating a thin layer of silicon plastic on the surface of ancient cultural relics and sculptures can prevent moss from growing and resist wind, rain, and weathering. The Monument to the People's Heroes on Tiananmen Square has a surface treated with silicon plastic, so it will always be white and fresh.
