Bureau of Alcohol, Tobacco, Firearms and Explosives
The Bureau of Alcohol, Tobacco and Explosives is a federal law enforcement organization within the United States Department of Justice. Its responsibilities include the investigation and prevention of federal offenses involving the unlawful use and possession of firearms and explosives; the ATF regulates via licensing the sale and transportation of firearms and explosives in interstate commerce. Many of the ATF's activities are carried out in conjunction with task forces made up of state and local law enforcement officers, such as Project Safe Neighborhoods; the ATF operates a unique fire research laboratory in Beltsville, where full-scale mock-ups of criminal arson can be reconstructed. The agency is led by Thomas E. Brandon, Acting Director, Ronald B. Turk, Acting Deputy Director; the ATF has 4,770 employees, an annual budget of $1.15 billion. The ATF was part of the United States Department of the Treasury, having been formed in 1886 as the "Revenue Laboratory" within the Treasury Department's Bureau of Internal Revenue.
The history of ATF can be subsequently traced to the time of the revenuers or "revenoors" and the Bureau of Prohibition, formed as a unit of the Bureau of Internal Revenue in 1920. It was made an independent agency within the Treasury Department in 1927, was transferred to the Justice Department in 1930, became a division of the FBI in 1933; when the Volstead Act, which established Prohibition in the United States, was repealed in December 1933, the Unit was transferred from the Department of Justice back to the Department of the Treasury, where it became the Alcohol Tax Unit of the Bureau of Internal Revenue. Special Agent Eliot Ness and several members of The "Untouchables", who had worked for the Prohibition Bureau while the Volstead Act was still in force, were transferred to the ATU. In 1942, responsibility for enforcing federal firearms laws was given to the ATU. In the early 1950s, the Bureau of Internal Revenue was renamed "Internal Revenue Service", the ATU was given the additional responsibility of enforcing federal tobacco tax laws.
At this time, the name of the ATU was changed to Tobacco Tax Division. In 1968, with the passage of the Gun Control Act, the agency changed its name again, this time to the Alcohol and Firearms Division of the IRS and first began to be referred to by the initials "ATF". In Title XI of the Organized Crime Control Act of 1970, Congress enacted the Explosives Control Act, 18 U. S. C. A. Chapter 40, which provided for close regulation of the explosives industry and designated certain arsons and bombings as federal crimes; the Secretary of the Treasury was made responsible for administering the regulatory aspects of the new law, was given jurisdiction over criminal violations relating to the regulatory controls. These responsibilities were delegated to the ATF division of the IRS; the Secretary and the Attorney General were given concurrent jurisdiction over arson and bombing offenses. Pub. L. 91-452, 84 Stat. 922, October 15, 1970. In 1972 ATF was established as an independent bureau within the Treasury Department on July 1, 1972, this transferred the responsibilities of the ATF division of the IRS to the new Bureau of Alcohol and Firearms.
Rex D. Davis oversaw the transition, becoming the bureau's first director, having headed the division since 1970. During his tenure, Davis shepherded the organization into a new era where federal firearms and explosives laws addressing violent crime became the primary mission of the agency; however and other alcohol issues remained priorities as ATF collected billions of dollars in alcohol and tobacco taxes, undertook major revisions of the federal wine labeling regulations relating to use of appellations of origin and varietal designations on wine labels. In the wake of the terrorist attack on the World Trade Center and the Pentagon on September 11, 2001, President George W. Bush signed into law the Homeland Security Act of 2002. In addition to the creation of the Department of Homeland Security, the law shifted ATF from the Department of the Treasury to the Department of Justice; the agency's name was changed to Bureau of Alcohol, Tobacco and Explosives. However, the agency still was referred to as the "ATF" for all purposes.
Additionally, the task of collection of federal tax revenue derived from the production of tobacco and alcohol products and the regulatory function related to protecting the public in issues related to the production of alcohol handled by the Bureau of Internal Revenue as well as by ATF, was transferred to the newly established Alcohol and Tobacco Tax and Trade Bureau, which remained within the Treasury Department. These changes took effect January 24, 2003. Complaints regarding the techniques used by ATF in their effort to generate firearm cases led to hearings before Congressional committees in the late 1970s and 1980s. At these hearings, evidence was received from citizens, charged by ATF, from experts who had studied ATF, from officials of the bureau itself. A Senate subcommittee report stated, "Based upon these hearings it is apparent that ATF enforcement tactics made possible by current federal firearms laws are constitutionally and reprehensible."The Subcommittee received evidence that ATF devoted its firearms enforcement efforts to the apprehension, upon technical malum prohibitum charges, of individuals who lack all criminal intent and knowledge.
Evidence received demonstrated that ATF agents tended to concentrate upon collector's items rather than "criminal street guns". In hearings before
United Kingdom
The United Kingdom the United Kingdom of Great Britain and Northern Ireland, sometimes referred to as Britain, is a sovereign country located off the north-western coast of the European mainland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, many smaller islands. Northern Ireland is the only part of the United Kingdom that shares a land border with another sovereign state, the Republic of Ireland. Apart from this land border, the United Kingdom is surrounded by the Atlantic Ocean, with the North Sea to the east, the English Channel to the south and the Celtic Sea to the south-west, giving it the 12th-longest coastline in the world; the Irish Sea lies between Great Ireland. With an area of 242,500 square kilometres, the United Kingdom is the 78th-largest sovereign state in the world, it is the 22nd-most populous country, with an estimated 66.0 million inhabitants in 2017. The UK is constitutional monarchy; the current monarch is Queen Elizabeth II, who has reigned since 1952, making her the longest-serving current head of state.
The United Kingdom's capital and largest city is London, a global city and financial centre with an urban area population of 10.3 million. Other major urban areas in the UK include Greater Manchester, the West Midlands and West Yorkshire conurbations, Greater Glasgow and the Liverpool Built-up Area; the United Kingdom consists of four constituent countries: England, Scotland and Northern Ireland. Their capitals are London, Edinburgh and Belfast, respectively. Apart from England, the countries have their own devolved governments, each with varying powers, but such power is delegated by the Parliament of the United Kingdom, which may enact laws unilaterally altering or abolishing devolution; the nearby Isle of Man, Bailiwick of Guernsey and Bailiwick of Jersey are not part of the UK, being Crown dependencies with the British Government responsible for defence and international representation. The medieval conquest and subsequent annexation of Wales by the Kingdom of England, followed by the union between England and Scotland in 1707 to form the Kingdom of Great Britain, the union in 1801 of Great Britain with the Kingdom of Ireland created the United Kingdom of Great Britain and Ireland.
Five-sixths of Ireland seceded from the UK in 1922, leaving the present formulation of the United Kingdom of Great Britain and Northern Ireland. There are fourteen British Overseas Territories, the remnants of the British Empire which, at its height in the 1920s, encompassed a quarter of the world's land mass and was the largest empire in history. British influence can be observed in the language and political systems of many of its former colonies; the United Kingdom is a developed country and has the world's fifth-largest economy by nominal GDP and ninth-largest economy by purchasing power parity. It has a high-income economy and has a high Human Development Index rating, ranking 14th in the world, it was the world's first industrialised country and the world's foremost power during the 19th and early 20th centuries. The UK remains a great power, with considerable economic, military and political influence internationally, it is sixth in military expenditure in the world. It has been a permanent member of the United Nations Security Council since its first session in 1946.
It has been a leading member state of the European Union and its predecessor, the European Economic Community, since 1973. The United Kingdom is a member of the Commonwealth of Nations, the Council of Europe, the G7, the G20, NATO, the Organisation for Economic Co-operation and Development and the World Trade Organization; the 1707 Acts of Union declared that the kingdoms of England and Scotland were "United into One Kingdom by the Name of Great Britain". The term "United Kingdom" has been used as a description for the former kingdom of Great Britain, although its official name from 1707 to 1800 was "Great Britain"; the Acts of Union 1800 united the kingdom of Great Britain and the kingdom of Ireland in 1801, forming the United Kingdom of Great Britain and Ireland. Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom, the name was changed to the "United Kingdom of Great Britain and Northern Ireland".
Although the United Kingdom is a sovereign country, Scotland and Northern Ireland are widely referred to as countries. The UK Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom; some statistical summaries, such as those for the twelve NUTS 1 regions of the United Kingdom refer to Scotland and Northern Ireland as "regions". Northern Ireland is referred to as a "province". With regard to Northern Ireland, the descriptive name used "can be controversial, with the choice revealing one's political preferences"; the term "Great Britain" conventionally refers to the island of Great Britain, or politically to England and Wales in combination. However, it is sometimes used as a loose synonym for the United Kingdom as a whole; the term "Britain" is used both as a synonym for Great Britain, as a synonym for the United Kingdom. Usage is mixed, with the BBC preferring to use Britain as shorthand only for Great Britain and the UK Government, while accepting that both terms refer to the United K
Fahrenheit
The Fahrenheit scale is a temperature scale based on one proposed in 1724 by Dutch–German–Polish physicist Daniel Gabriel Fahrenheit. It uses the degree Fahrenheit as the unit. Several accounts of how he defined his scale exist; the lower defining point, 0 °F, was established as the freezing temperature of a solution of brine made from equal parts of ice and salt. Further limits were established as the melting point of ice and his best estimate of the average human body temperature; the scale is now defined by two fixed points: the temperature at which water freezes into ice is defined as 32 °F, the boiling point of water is defined to be 212 °F, a 180 °F separation, as defined at sea level and standard atmospheric pressure. At the end of the 2010s, Fahrenheit was used as the official temperature scale only in the United States, its associated states in the Western Pacific, the Bahamas, the Cayman Islands and Liberia. Antigua and Barbuda and other islands which use the same meteorological service, such as Anguilla, the British Virgin Islands and Saint Kitts and Nevis, as well as Bermuda and the Turks and Caicos Islands, use Fahrenheit and Celsius.
All other countries in the world now use the Celsius scale, named after Swedish astronomer Anders Celsius. On the Fahrenheit scale, the freezing point of water is 32 degrees Fahrenheit and the boiling point is 212 °F; this puts the freezing points of water 180 degrees apart. Therefore, a degree on the Fahrenheit scale is 1⁄180 of the interval between the freezing point and the boiling point. On the Celsius scale, the freezing and boiling points of water are 100 degrees apart. A temperature interval of 1 °F is equal to an interval of 5⁄9 degrees Celsius; the Fahrenheit and Celsius scales intersect at −40°. Absolute zero is −273.15 °C or −459.67 °F. The Rankine temperature scale uses degree intervals of the same size as those of the Fahrenheit scale, except that absolute zero is 0 °R — the same way that the Kelvin temperature scale matches the Celsius scale, except that absolute zero is 0 K; the Fahrenheit scale uses the symbol ° to denote a point on the temperature scale and the letter F to indicate the use of the Fahrenheit scale, as well as to denote a difference between temperatures or an uncertainty in temperature.
For an exact conversion, the following formulas can be applied. Here, f is the value in Fahrenheit and c the value in Celsius: f °Fahrenheit to c °Celsius: °F × 5°C/9°F = /1.8 °C = c °C c °Celsius to f °Fahrenheit: + 32 °F = °F + 32 °F = f °FThis is an exact conversion making use of the identity −40 °F = −40 °C. Again, f is the value in Fahrenheit and c the value in Celsius: f °Fahrenheit to c °Celsius: − 40 = c. C °Celsius to f °Fahrenheit: − 40 = f. Fahrenheit proposed his temperature scale in 1724, basing it on two reference points of temperature. In his initial scale, the zero point was determined by placing the thermometer in a mixture "of ice, of water, of ammonium chloride or of sea salt"; this combination forms a eutectic system which stabilizes its temperature automatically: 0 °F was defined to be that stable temperature. The second point, 96 degrees, was the human body's temperature. According to a story in Germany, Fahrenheit chose the lowest air temperature measured in his hometown Danzig in winter 1708/09 as 0 °F, only had the need to be able to make this value reproducible using brine.
According to a letter Fahrenheit wrote to his friend Herman Boerhaave, his scale was built on the work of Ole Rømer, whom he had met earlier. In Rømer's scale, brine freezes at zero, water freezes and melts at 7.5 degrees, body temperature is 22.5, water boils at 60 degrees. Fahrenheit multiplied each value by four in order to eliminate fractions and make the scale more fine-grained, he re-calibrated his scale using the melting point of ice and normal human body temperature. Fahrenheit soon after observed; the use of the freezing and boiling points of water as thermometer fixed reference points became popular following the work of Anders Celsius and these fixed points were adopted by a committee of the Royal Society led by Henry Cavendish in 1776. Under this system, the Fahrenheit scale is redefined so that the freezing point of water is 32 °F, the boiling point is 212 °F or 180 degrees higher, it is for this reason that normal human body temperature is 98° on the revised scale. In the present-day Fahrenheit scale, 0 °F no longer corresponds to the eutectic temperature of ammonium chloride brine as described above.
Instead, that eutectic is at 4 °F on the final Fahrenheit scale. The Rankine temperature s
Fireworks
Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes. The most common use of a firework is as part of a fireworks display, a display of the effects produced by firework devices. Fireworks competitions are regularly held at a number of places. Fireworks take many forms to produce the four primary effects: noise, light and floating materials, they may be designed to burn with colored flames and sparks including red, yellow, blue and silver. Displays are common throughout the world and are the focal point of many cultural and religious celebrations. Fireworks are classified as to where they perform, either as a ground or aerial firework. In the latter case they may be shot into the air by a mortar; the most common feature of fireworks is a paper or pasteboard tube or casing filled with the combustible material pyrotechnic stars. A number of these tubes or cases are combined so as to make when kindled, a great variety of sparkling shapes variously colored.
A skyrocket is a common form of firework. The aerial shell, however, is the backbone of today's commercial aerial display, a smaller version for consumer use is known as the festival ball in the United States; such rocket technology has been used for the delivery of mail by rocket and is used as propulsion for most model rockets. Fireworks were invented in medieval China around the early 9th century. One of the cultural practices for fireworks was to scare away evil spirits. Cultural events and festivities such as the Chinese New Year and the Mid-Autumn Moon Festival were and still are times when fireworks are guaranteed sights. China is exporter of fireworks in the world. Colored fireworks were invented in Europe in the 1830s. Modern skyrocket fireworks were invented in the early 20th century; the earliest documentation of fireworks dates back to about the early 9th-century medieval Chinese Tang Dynasty. The fireworks were used to accompany many festivities; the art and science of firework making has developed into an independent profession.
In China, pyrotechnicians were respected for their knowledge of complex techniques in mounting firework displays. Chinese people believed that the fireworks could expel evil spirits and bring about luck and happiness. During the Song Dynasty, many of the common people could purchase various kinds of fireworks from market vendors, grand displays of fireworks were known to be held. In 1110, a large fireworks display in a martial demonstration was held to entertain Emperor Huizong of Song and his court. A record from 1264 states that a rocket-propelled firework went off near the Empress Dowager Gong Sheng and startled her during a feast held in her honor by her son Emperor Lizong of Song. Rocket propulsion was common in warfare, as evidenced by the Huolongjing compiled by Liu Bowen and Jiao Yu. In 1240 the Arabs acquired knowledge of its uses from China. A Syrian named Hasan al-Rammah wrote of rockets and other incendiaries, using terms that suggested he derived his knowledge from Chinese sources, such as his references to fireworks as "Chinese flowers".
In regards to colored fireworks, this was derived and developed from earlier Chinese application of chemical substances to create colored smoke and fire. Such application appears in the Huolongjing and Wubeizhi, which describes recipes, several of which used low-nitrate gunpowder, to create military signal smokes with various colors. In the Wubei Huolongjing, two formulas appears for firework-like signals, the sanzhangju and baizhanglian, that produces silver sparkles in the smoke. In the Huoxilüe by Zhao Xuemin, there are several recipes with low-nitrate gunpowder and other chemical substances to tint flames and smoke; the Chinese pyrotechnics have been written about by foreign authors such as Antoine Caillot who wrote "It is certain that the variety of colours which the Chinese have the secret of giving to flame is the greatest mystery of their fireworks." Or Sir John Barrow who wrote "The diversity of colours indeed with which the Chinese have the secret of cloathing fire seems to be the chief merit of their pyrotechny."Fireworks were produced in Europe by the 14th century, becoming popular by the 17th century.
Lev Izmailov, ambassador of Peter the Great, once reported from China: "They make such fireworks that no one in Europe has seen." In 1758, the Jesuit missionary Pierre Nicolas le Chéron d'Incarville, living in Beijing, wrote about the methods and composition on how to make many types of Chinese fireworks to the Paris Academy of Sciences, which revealed and published the account five years later. Amédée-François Frézier published his revised work Traité des feux d'artice pour le spectacle in 1747, covering the recreational and ceremonial uses of fireworks, rather than their military uses. Music for the Royal Fireworks was composed by George Frideric Handel in 1749 to celebrate the Peace treaty of Aix-la-Chapelle, declared the previous year. Improper use of fireworks may be dangerous, both to bystanders. For this reason, the use of fireworks is legally restricted. Display fireworks are restricted by law for use by professionals
U.S. Consumer Product Safety Commission
The United States Consumer Product Safety Commission is an independent agency of the United States government. The CPSC seeks to promote the safety of consumer products by addressing "unreasonable risks" of injury. In part due to its small size, the CPSC attempts to coordinate with outside parties—including companies and consumer advocates—to leverage resources and expertise to achieve outcomes that advance consumer safety; the agency was created in 1972 through the Consumer Product Safety Act. The agency reports to the President; the CPSC has five commissioners, who are nominated by the president and confirmed by the Senate for staggered seven-year terms. The Commission was run by three commissioners or fewer. Since 2009, the agency has been led by five commissioners, one of whom serves as chairman; the commissioners set policy for the CPSC. The CPSC is headquartered in Maryland; the commissioners of the CPSC are appointed by the U. S. president and with the consent of the U. S. Senate; as with some other U.
S. federal independent agencies, commissioners are selected as members of political parties. Although the president is entitled by statute to select the chairman, no more than three commissioners may belong to the same party. Thus, the president is expected to consult with members of the opposite party in the Senate to select members of the commission from the opposite party; the commissioners vote on selecting the vice chairman, who becomes acting chairman if the chairman’s term ends upon resignation or expiration. The CPSC regulates the manufacture and sale of more than 15,000 different consumer products, from cribs to all-terrain vehicles. Products excluded from the CPSC's jurisdiction include those named by law as under the jurisdiction of other federal agencies; the CPSC fulfills its mission by banning dangerous consumer products, establishing safety requirements for other consumer products, issuing recalls of products on the market, researching potential hazards associated with consumer products.
The CPSC makes rules about consumer products when it identifies a consumer product hazard, not addressed by an industry voluntary consensus standard, or when Congress directs it to do so. Its rules can specify basic design requirements, or they can amount to product bans, as in the case of small high-powered magnets, which the CPSC attempted to ban. For certain infant products, the CPSC regulates when voluntary standards exist; the CPSC is required to follow a scientific process to develop mandatory rules. Failing to do so can justify the revocation of a rule, as was the case in a Tenth Circuit decision vacating the CPSC's ban on small high-powered magnets; the CPSC learns about unsafe products in several ways. The agency maintains a consumer hotline through which consumers may report concerns about unsafe products or injuries associated with products. Product safety concerns may be submitted through SaferProducts.gov The agency operates the National Electronic Injury Surveillance System, a probability sample of about 100 hospitals with 24-hour emergency rooms.
NEISS collects data on consumer product related injuries treated in ERs and can be used to generate national estimates. The agency works with and shares information with other governments, both in the U. S. and with international counterparts. The CPSC works on a variety of publicity campaigns to raise awareness of safety. For example, the CPSC blows up mannequins to demonstrate the dangers of improper use of fireworks. Since February 2015, the average civil penalty has been $2.9 million. In April 2018, Polaris Industries agreed to pay a record $27.25 million civil penalty for failing to report defective off-road vehicles. On November 2, 2007, the Washington Post reported that between 2002 and the date of their report, former chairman Hal Stratton and current commissioner and former acting chairman Nancy Nord had taken more than 30 trips paid for by manufacturing groups or lobbyists representing industries that are under the supervision of the agency. According to the Post, the groups paid for over $60,000 travel and related expenses during this time.
In 1972 when the agency was created, it had 786 staff members. By 2008 it had 401 employees on a budget of $43 million, but the Consumer Product Safety Improvement Act passed in 2008 increases funding $136.4 million in 2014 with full-time employees to at least 500 by 2013. 2007 has been called the "Year of the Recall" in the United States, the CPSC alone obtained 473 voluntary recalls in 2007, a record. This notably included many incidents with lead in other children's products; these issues led to the legislative interest in the reform of the agency, the final result of these efforts was the passage of the Consumer Product Safety Improvement Act in 2008. The bill increased funding and staffing for the CPSC, placed stricter limits on lead levels in children's products
Aluminium
Aluminium or aluminum is a chemical element with symbol Al and atomic number 13. It is a silvery-white, soft and ductile metal in the boron group. By mass, aluminium makes up about 8% of the Earth's crust; the chief ore of aluminium is bauxite. Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is found combined in over 270 different minerals. Aluminium is remarkable for its low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the aerospace industry and important in transportation and building industries, such as building facades and window frames; the oxides and sulfates are the most useful compounds of aluminium. Despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals; because of these salts' abundance, the potential for a biological role for them is of continuing interest, studies continue.
Of aluminium isotopes, only 27Al is stable. This is consistent with aluminium having an odd atomic number, it is the only aluminium isotope that has existed on Earth in its current form since the creation of the planet. Nearly all the element on Earth is present as this isotope, which makes aluminium a mononuclidic element and means that its standard atomic weight equates to that of the isotope; the standard atomic weight of aluminium is low in comparison with many other metals, which has consequences for the element's properties. All other isotopes of aluminium are radioactive; the most stable of these is 26Al and therefore could not have survived since the formation of the planet. However, 26Al is produced from argon in the atmosphere by spallation caused by cosmic ray protons; the ratio of 26Al to 10Be has been used for radiodating of geological processes over 105 to 106 year time scales, in particular transport, sediment storage, burial times, erosion. Most meteorite scientists believe that the energy released by the decay of 26Al was responsible for the melting and differentiation of some asteroids after their formation 4.55 billion years ago.
The remaining isotopes of aluminium, with mass numbers ranging from 21 to 43, all have half-lives well under an hour. Three metastable states are known, all with half-lives under a minute. An aluminium atom has 13 electrons, arranged in an electron configuration of 3s23p1, with three electrons beyond a stable noble gas configuration. Accordingly, the combined first three ionization energies of aluminium are far lower than the fourth ionization energy alone. Aluminium can easily surrender its three outermost electrons in many chemical reactions; the electronegativity of aluminium is 1.61. A free aluminium atom has a radius of 143 pm. With the three outermost electrons removed, the radius shrinks to 39 pm for a 4-coordinated atom or 53.5 pm for a 6-coordinated atom. At standard temperature and pressure, aluminium atoms form a face-centered cubic crystal system bound by metallic bonding provided by atoms' outermost electrons; this crystal system is shared by some other metals, such as copper. Aluminium metal, when in quantity, is shiny and resembles silver because it preferentially absorbs far ultraviolet radiation while reflecting all visible light so it does not impart any color to reflected light, unlike the reflectance spectra of copper and gold.
Another important characteristic of aluminium is its low density, 2.70 g/cm3. Aluminium is a soft, lightweight and malleable with appearance ranging from silvery to dull gray, depending on the surface roughness, it is nonmagnetic and does not ignite. A fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation; the yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has stiffness of steel, it is machined, cast and extruded. Aluminium atoms are arranged in a face-centered cubic structure. Aluminium has a stacking-fault energy of 200 mJ/m2. Aluminium is a good thermal and electrical conductor, having 59% the conductivity of copper, both thermal and electrical, while having only 30% of copper's density. Aluminium is capable of superconductivity, with a superconducting critical temperature of 1.2 kelvin and a critical magnetic field of about 100 gauss.
Aluminium is the most common material for the fabrication of superconducting qubits. Aluminium's corrosion resistance can be excellent due to a thin surface layer of aluminium oxide that forms when the bare metal is exposed to air preventing further oxidation, in a process termed passivation; the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts in the presence of dissimilar metals. In acidic solutions, aluminium reacts with water to form hydrogen, in alkaline ones to form aluminates—protective passivation under these conditions is negligible; because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium. However, because
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