1. tungsten, the name comes from the previous Swedish name tungsten, which means "heavy stone". It is a rare metal and naturally exists on the surface of the earth. It was identified as a new element in 178 1 and isolated as a metal for the first time in 1783. Its solidity is remarkable, and its melting point is the highest among all elements, with a melting point of 3422℃ and a boiling point of 5930℃. In addition, its density is 19.3 times that of water and much higher than that of lead. In fact, it is the heaviest element known to be essential for any organism, but it can interfere with the metabolism of molybdenum and copper, which are somewhat toxic to animal life.
2. Steel is an alloy of iron and carbon, containing less than 2% carbon, 1% manganese and a small amount of silicon, phosphorus, sulfur and oxygen. Because of its high tensile strength and low cost, it is the main component of shipbuilding, infrastructure, tools, automobiles, machines, electrical appliances and weapons, so it is called the most important engineering and building materials in the world. . It is used in all aspects of human life, from tableware to cars, refrigerators and washing machines. The most important feature of steel is that it can be recycled repeatedly without losing its performance.
3. Cr-Cr is a shiny, brittle and hard metal, usually silver-gray. This is a highly polished metal that won't change color in air. In addition, it is unstable in oxygen and will immediately produce a thin oxygen-tight oxide layer. However, chromium is widely recognized for its large-scale use as a component of stainless steel, because it has excellent hardness, corrosion resistance and polishing ability to obtain a shiny appearance.
4. Titanium is a shiny transition metal with a silver appearance, low density and high strength. It has good corrosion resistance to seawater, aqua regia and chlorine. In addition, titanium is a "new" metal, which was discovered in 1790. After a long period of maturity, it began industrial production in 1948. Due to its rich reserves and excellent biological friendliness, titanium is a material that is friendly to the environment and human beings.
5. Iron and iron is considered as the tenth most abundant element in the universe, which exists in four different crystal forms. In addition, it is a common and cheap metal, which usually exists in black. It is attracted by magnets and used to make steel. It will rust in humid air, but not in dry air. Today, it is the most widely used metal, accounting for 95% of all metal production in the world. From food containers to private cars, from screwdrivers to washing machines, from cargo ships to paper nails, they are widely used. The main mining areas are China, Brazil, Australia, Russian and Ukrainian.
Vanadium is one of the strongest metals in the world. It is a soft, rare and tough metal, usually gray. Mainly used for producing some alloys. It is named after the northern beauty god Vanadis because of its beautiful color. When vanadium is mixed with aluminum in titanium alloy, it is widely used in jet engines and high-speed gas frames, as well as key parts such as axles, crankshafts and gears. In addition, it is also used as a medicine supplement. In addition, the largest resources of vanadium come from South Africa and Russia.
7. americium is a rare metal found on the earth, which may be the most expensive of all rare elements. It exists in a small amount with all other rare earth metals on the earth, and it is difficult to separate from other rare elements. The main producers of americium are the United States, Australia, China, Brazil, Sri Lanka and India. In addition, americium is widely used in refineries and petroleum industry, which makes it very expensive. Besides, it is also used in various methods, such as polymerization, hydrogenation and alkylation.
Zirconium is a transition metal, which can easily form stable compounds. It is silver-gray and has high corrosion resistance. Zirconium alloys have many uses, including pipes, fittings and heat exchangers. Zirconium is also used in steel alloys, colored glazes, bricks, ceramics, abrasives, flashlights, filaments, artificial gem and some deodorants.
9. Osmium Osmium is the known densest metal and belongs to the platinum group metal. It is a shiny silver metal, unaffected by water and acid. Used as catalyst in some alloys and industries. Because of its high hardness and excellent corrosion resistance, it was once widely used to produce high-quality pens, compasses, long-life phonograph needles and pen tips of clock bearings.
10. Tantalum is one of the strongest metals in the world. Tantalum is a soft, shiny silver metal, which is almost corrosion-resistant because it has an oxide film on its surface. Tantalum is widely used in aircraft engines and electrical equipment, such as capacitors. Tantalum is almost free from chemical attack, which is why it is used in chemical industry, such as heat exchanger in boilers that evaporate strong acids. But the main producing areas include Thailand, Australia, Congo, Brazil, Portugal and Canada.