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- Vincent WongLv 71 十年前最愛解答
Magnesium is the chemical element in the periodic table that has the symbol Mg and atomic number 12 and an atomic mass of 24.31. Magnesium is the eighth most abundant element and constitutes about 2% of the Earth's crust by weight, and it is the third most plentiful element dissolved in seawater. Magnesium ion is essential to all living cells. The free element (metal) is not found in nature. Once produced from magnesium salts, this alkaline earth metal is primarily used as an alloying agent to make aluminium-magnesium alloys, sometimes called magnalium or magnelium.
The name originates from the Greek word for a district in Thessaly called Magnesia. Joseph Black in Scotland recognized magnesium as being an element in 1755, Sir Humphry Davy electrolytically isolated pure magnesium metal in 1808 from a mix of magnesia and HgO, and A. A. B. Bussy prepared it in coherent form in 1831. Magnesium is the eighth most abundant element in the earth's crust. It is an alkaline earth metal and therefore does not occur uncombined with other elements. It is found in large deposits of magnesite, dolomite, and other minerals.
1. As the metal
Magnesium is the third most commonly used structural metal, following steel and aluminium.
Magnesium compounds, primarily magnesium oxide, are used mainly as refractory material in furnace linings for producing iron, steel, nonferrous metals, glass and cement. Magnesium oxide and other compounds also are used in agricultural, chemical and construction industries. As a metal, this element's principal use is as an alloying additive to aluminium with these aluminium-magnesium alloys being used mainly for beverage cans.
2. Food sources
Magnesium, in its purest form, can be compared to aluminium, and is strong and light, so it is used in several high volume part manufacturing applications, including automotive and truck components. Specialty, high-grade car wheels of magnesium alloy are called mag wheels.
Green vegetables such as spinach provide magnesium because the center of the chlorophyll molecule contains magnesium. Nuts (especially almonds), seeds, and some whole grains are also good sources of magnesium.
3. In magnesium compound
Magnesium's hydroxide is used in milk of magnesia, its chloride and citrate used as oral magnesium supplements, and its sulfate (Epsom salts) for various purposes in medicine, and elsewhere.
Dead-burned magnesite is used for refractory purposes such as brick and liners in furnaces and converters.
Magnesium carbonate (MgCO3) powder is also used by athletes, such as gymnasts and weightlifters, to improve the grip on objects – the apparatus or lifting bar.
The magnesium ion is necessary for all life (see magnesium in biological systems), so magnesium salts are an additive for foods, fertilizers (Mg is a component of chlorophyll), and culture media.
- 1 十年前
- 1 十年前