Even very pure aluminum is vigorously attacked by alkalies such as sodium and potassium hydroxide to yield hydrogen and the aluminate ion. Concentrated nitric acid, however, can be shipped in aluminum tank cars because it renders the metal passive. Metallic aluminum and its oxide and hydroxide are nontoxic.Īluminum is slowly attacked by most dilute acids and rapidly dissolves in concentrated hydrochloric acid. All natural aluminum is the stable isotope aluminum-27. It crystallizes in the face-centred cubic structure. Its thermal conductivity is about one-half that of copper its electrical conductivity, about two-thirds. Though chemically active, aluminum is nevertheless highly corrosion-resistant, because in air a hard, tough oxide film forms on its surface.Īluminum is an excellent conductor of heat and electricity. The metal is only about one-third as dense as iron or copper. Ductile and highly malleable, aluminum can be drawn into wire or rolled into thin foil. Pure aluminum (99.996 percent) is quite soft and weak commercial aluminum (99 to 99.6 percent pure) with small amounts of silicon and iron is hard and strong. Get a Britannica Premium subscription and gain access to exclusive content. The metal and its alloys are used extensively for aircraft construction, building materials, consumer durables (refrigerators, air conditioners, cooking utensils), electrical conductors, and chemical and food-processing equipment. Uses and propertiesĪluminum is added in small amounts to certain metals to improve their properties for specific uses, as in aluminum bronzes and most magnesium-base alloys or, for aluminum-base alloys, moderate amounts of other metals and silicon are added to aluminum. For more specific information about the mining, refining, and production of aluminum, see aluminum processing. During the 1960s aluminum moved into first place, ahead of copper, in world production of nonferrous metals. When electric power became relatively plentiful and cheap, almost simultaneously Charles Martin Hall in the United States and Paul-Louis-Toussaint Héroult in France discovered (1886) the modern method of commercially producing aluminum: electrolysis of purified alumina (Al 2O 3) dissolved in molten cryolite (Na 3AlF 6). The new metal was introduced to the public (1855) at the Paris Exposition at about the time that it became available (in small amounts at great expense) by the sodium reduction of molten aluminum chloride through the Deville process. German chemist Friedrich Wöhler, using potassium metal as the reducing agent, produced aluminum powder (1827) and small globules of the metal (1845), from which he was able to determine some of its properties. British chemist Sir Humphry Davy had prepared (1809) an iron-aluminum alloy by electrolyzing fused alumina (aluminum oxide) and had already named the element aluminum the word later was modified to aluminium in England and some other European countries. In the latter half of the 18th century, chemists such as Antoine Lavoisier recognized alumina as the potential source of a metal.Ĭrude aluminum was isolated (1825) by Danish physicist Hans Christian Ørsted by reducing aluminum chloride with potassium amalgam. Pliny refers to alumen, now known as alum, a compound of aluminum widely employed in the ancient and medieval world to fix dyes in textiles. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!įacts You Should Know: The Periodic Table Quizīefore 5000 bce people in Mesopotamia were making fine pottery from a clay that consisted largely of an aluminum compound, and almost 4,000 years ago Egyptians and Babylonians used aluminum compounds in various chemicals and medicines.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions. Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.
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