Aluminum, symbol Al, the most abundant metallic element in the earth's crust. The atomic number of aluminum is 13; the element is in group 13 (IIIa) of the periodic table.
Hans Christian Orstead, Danish chemist, first isolated aluminum in 1825, using a chemical process involving potassium amalgam. Between 1827 and 1845, Friedrich Wöhler, a German chemist, improved Oersted's process by using metallic potassium. He was the first to measure the specific gravity of aluminum and show its lightness. In 1854 Henri Sainte-Claire Deville, in France, obtained the metal by reducing aluminum chloride with sodium. Aided by the financial backing of Napoleon III, Deville established a large-scale experimental plant and displayed pure aluminum at the Paris Exposition of 1855.
Aluminum is a lightweight, silvery metal. The atomic weight of aluminum is 26.9815; the element melts at 660° C (1220° F), boils at 2467° C (4473° F), and has a specific gravity of 2.7. Aluminum is a strongly electropositive metal and extremely reactive. In contact with air, aluminum rapidly becomes covered with a tough, transparent layer of aluminum oxide that resists further corrosive action. For this reason, materials made of aluminum do not tarnish or rust. The metal reduces many other metallic compounds to their base metals. For example, when thermite (a mixture of powdered iron oxide and aluminum) is heated, the aluminum rapidly removes the oxygen from the iron; the heat of the reaction is sufficient to melt the iron. This phenomenon is used in the thermite process for welding iron .
The oxide of aluminum is amphoteric—showing both acidic and basic properties. The most important compounds include the oxide, hydroxide, sulfate, and mixed sulfate compounds. Anhydrous aluminum chloride is important in the oil and synthetic-chemical industries. Many gemstones—ruby and sapphire, for example—consist mainly of crystalline aluminum oxide.
Aluminum is the most abundant metallic constituent in the crust of the earth; only the nonmetals oxygen and silicon are more abundant. Aluminum is never found as a free metal; commonly as aluminum silicate or as a silicate of aluminum mixed with other metals such as sodium, potassium, iron, calcium, and magnesium. These silicates are not useful ores, for it is chemically difficult, and therefore an expensive process, to extract aluminum from them. bauxite an impure h...
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...cling of such containers is an increasingly important energy-conservation measure. Aluminum's resistance to corrosion in salt water also makes it useful in boat hulls and various aquatic devices.
A wide variety of coating alloys and wrought alloys can be prepared that give the metal greater strength, castability, or resistance to corrosion or high temperatures. Some new alloys can be used as armor plate for tanks, personnel carriers, and other military vehicles.
In 1886 the world production of aluminum was less than 45 kg (less than 100 lb), and its price was more than $11 per kg (more than $5 per lb). In 1989, by contrast, the estimated world production of primary aluminum was 18 million metric tons and an estimated 4 million metric tons was produced in the United States alone, whereas the price of aluminum was less than $2 per kg. U.S. consumption, by major markets, consisted of containers and packaging, 31 percent; building and construction, 20 percent; transportation, 24 percent; electric equipment, 10 percent; consumer durables, 9 percent; and miscellaneous, 6 percent. In 1989, recycled aluminum accounted for over 20 percent of total aluminum consumption in the United States.
Aluminum is the third most abundant element and most abundant metal in the Earth’s crust. Aluminum is never found in the free element state in nature. It
Objective The ability to analyze a substance and determine properties of the substance is an important skill for AP Chemistry students. Major concepts for the “Analysis of Alum” laboratory are percent composition, water of hydration, and molecular formula. They will be used in three different experiments to determine the melting point of alum, the mole ratio of hydrated water to anhydrous alum, and percent of sulfate ion contained in alum. The values acquired in the lab should be close to the calculated values of 92.5 ˚F, 12 moles of water to 1 mole of alum, and 59%, respectively.
A bauxite is a mixture consisting of hydrated aluminum oxide minerals and mineral impurities which are formed by weathered aluminum bearing rocks. In 1891 bauxite was mined in Alabama from the Rock Run. However, mining came to a sudden stop because metallurgical grade bauxite became very hard to obtain. Production started back up in 1927 and has been running on a maintained basis. Due to irregular distributions of bauxite deposits, exploratory test drilling must be conducted before any mining. Alabama bauxite is used in the making of high temperature products, abrasives, and chemicals. (Tew, 6)
Alloys in the ornament manufacturing are a general use of gold. Because of it is...
Arsenic has been one of the elements most mentioned during the middle and even modern age. It was formerly known by Chinese, Romans, Greeks and even earlier, by the Babylonians. The Greeks used the arsenic oxide (III) as a depilatory, and 4,000 years before the Christian era, arsenic was involved in the development of early bronzes. However, the arsenic was released in early civilizations through compounds or substances containing the element, which by its color and appearance would favor the conversion of base metals into gold. It was also used by the alchemists in the method of making the pill of immortality. In the philosophy of alchemy, arsenic represents the masculine principle. The masculinity of arsenic was different, because it combined with an element that was considered as masculine such as sulfur, forming orpiment and realgar.
Partitioning and isolation, remains the qualities of server virtualization, by permitting simple and safe server consolidation. Through uniting, the number of physical server, it can be significantly reduced. This one is bringing the advantages of decreased power consumption, floor space, and air conditioning costs. It is necessary to note that it does not change even though the number of physical servers is brought down, to
If the cancer is at the earliest stage it can be treatable. ACS also provides and informs patients to stay healthy by staying away from tobacco, eat healthy and get advice, how to be safe while outdoors in the sun, there are also other ways to protect them. In addition, there are tools and calculators to help make healthy eating habits easier. Lastly, there are cancer screening guidelines, which help increase detecting cancers early.
In 1817, an aging Swedish chemist was pouring over his work on a late afternoon in Stockholm, Sweden. He was analyzing a strange ore named Petalite that had been procured from an island off the coast of Sweden called Utö. The ore Petalite (which is now recognized to be LiAl(Si2O5)2) had been discovered by a Brazilian scientist, José Bonifácio de Andrada e Silva towards the end of the 18th century on a visit to Sweden. This Swedish scientist, Johann August Arfvedson, detected traces of an unknown substance in his sample of Petalite. This was the first discovery of Lithium.
Mr. Cronstedt discovered nickel in a mineral called niccolite. He originally planned to extract copper from this new mineral but got none at all. This is why nickel, at first, was called "false copper". Instead, Cronstedt got a silvery-white metal, which was eventually used for other things.
American families are struggling with problems of child abuse and obesity. These problems are issues for many reasons, but one major reason is the availability of fast food. Parents often take advantage of the easy and affordable options for food; however, when parents begin to take their children to a place that serves this food every day, it turns into child abuse. The parent or guardian neglects the need of nutrition for their child, causing the child to become overweight, which can be seen as disfigurement. Neglect and disfigurement are harsh words, but they are necessary to show the severity of the issue.
To begin with, virtualization reduces hardware costs by reducing consolidating equipment. Initially, Seabreeze will reduce the physical server infrastructure by 70%. The project will upgrade the data center to 21 energy efficient servers with enough resources (CPUs, networking, memory, and disk storage) to host the virtual infrastructure. As for storage, the VMs will be stored on a storage area network (SAN). That is to say, the server cluster will be connected to a petabyte SAN for data
The American Cancer Society is a nationwide voluntary health organization dedicated to eliminate cancer. The goals of ACS is to prevent cancer, save lives, and diminish the suffering from the disease through research, education, advocacy, and service. Today, being diagnosed with cancer presents devastating news to the victim, their family, and friends. A lot of unanswered questions come to the person’s mind, the pain, suffering and death. Questions of what the person had done throughout their lives that could have possibly led to their present diagnosis.
The days of the old-fashioned computer dumb-terminals that connected to a mainframe computer which encompassed an entire room are long gone. Most college students weren’t even born yet at the height of the mainframe computer generation. Desktop virtualization is the latest and greatest emerging technology that calls for a reinvention, of sorts, of those dumb-terminals. Although no universal definition of what a virtual desktop is exists yet, the basic idea is that one server or a number of servers run the application software that the business user connects to. The physical desktop does not run the application itself as it resides on the server.
...ame physical hardware, IT administrators can consolidate hardware and instantly build production, quality assurance, and test environments. Storage virtualization enables the pooling of physical storage from multiple network storage sources into what appears to be a single storage device. This significantly helps administrators perform backup, expansion, archiving, and recovery tasks more effortlessly, and in a small amount of time. Virtualization can provide various benefits, including reducing hardware cost, better energy usage, optimization of workloads, flexibility and responsive. Virtualization allows the IT administrator to efficiently access and manages resources to reduce operations and systems management costs while maintaining needed capacity. With these types of benefits, most companies find it easy to justify the cost of implementing virtualization
A major difficulty with the virtual machine involves disk systems. For instance, the physical machine has two disk drives but wants to support five virtual machines. The physical machine is unable to allocate a disk drive to each virtual machine because the virtual machine software itself will need substantial disk space to provide virtual memory and spooling. To solve this dilemma, virtual drives that are identical in all respects except for size are provided. The system implements each virtual disk by allocating as many tracks on the physical disks as the virtual disk needs.