173-755: The Sentinelese , also known as the Sentineli and the North Sentinel Islanders , are an indigenous people who inhabit North Sentinel Island in the Bay of Bengal in the northeastern Indian Ocean . Designated a particularly vulnerable tribal group and a Scheduled Tribe , they belong to the broader class of Andamanese peoples . Along with the Great Andamanese , the Jarawas , the Onge ,
346-491: A precipitate of aluminium hydroxide , Al(OH) 3 , forms. This is useful for clarification of water, as the precipitate nucleates on suspended particles in the water, hence removing them. Increasing the pH even further leads to the hydroxide dissolving again as aluminate , [Al(H 2 O) 2 (OH) 4 ] , is formed. Aluminium hydroxide forms both salts and aluminates and dissolves in acid and alkali, as well as on fusion with acidic and basic oxides. This behavior of Al(OH) 3
519-525: A "less classical sound". This name persisted: although the -um spelling was occasionally used in Britain, the American scientific language used -ium from the start. Most scientists throughout the world used -ium in the 19th century; and it was entrenched in several other European languages, such as French , German , and Dutch . In 1828, an American lexicographer, Noah Webster , entered only
692-616: A 2014 circumnavigation, researchers recorded six females, seven males (all apparently under 40 years old) and three children younger than four. A handbook released in 2016 by the Anthropological Survey of India on "Vulnerable Tribe Groups" estimates the population at between 100 and 150. The Sentinelese are hunter-gatherers . They use spears with bows and arrows to hunt terrestrial wildlife and more rudimentary methods to catch local seafood, such as mud crabs and molluscan shells. They are believed to eat many molluscs , given
865-469: A 4 January 1991 visit, the Sentinelese approached the party without weaponry for the first time. They collected coconuts that were offered but retreated to the shore as the team gestured for them to come closer. The team returned to the main ship, MV Tarmugli . It returned to the island in the afternoon to find at least two dozen Sentinelese on the shoreline, one of whom pointed a bow and arrow at
1038-499: A Swedish chemist, Jöns Jacob Berzelius , in which the name aluminium is given to the element that would be synthesized from alum. (Another article in the same journal issue also refers to the metal whose oxide is the basis of sapphire , i.e. the same metal, as to aluminium .) A January 1811 summary of one of Davy's lectures at the Royal Society mentioned the name aluminium as a possibility. The next year, Davy published
1211-488: A boy shot a metal-headed arrow that pierced the Bible he was holding in front of his chest, after which he retreated again. On his final visit, on 17 November, Chau instructed the fishermen to leave without him. The fishermen later saw the islanders dragging Chau's body, and the next day they saw his body on the shore. Indigenous people There is no generally accepted definition of Indigenous peoples , although in
1384-414: A census. On the first occasion, he came across eight men on the beach and another five in two canoes, who retreated into the forest. The party progressed some miles into the island without facing any hostile response and saw a few huts with slanted roofs. Eventually, failing to find anyone, Bonnington and his men left the island. Notably, the Sentinelese were counted as a standalone group for the first time in
1557-561: A chemistry textbook in which he used the spelling aluminum . Both spellings have coexisted since. Their usage is currently regional: aluminum dominates in the United States and Canada; aluminium is prevalent in the rest of the English-speaking world. In 1812, British scientist Thomas Young wrote an anonymous review of Davy's book, in which he proposed the name aluminium instead of aluminum , which he thought had
1730-643: A colony in New Mexico. However, the heartland of the Spanish colonies remained New Spain (including Mexico and most of Central America) and Peru (including most of South America). In the 17th century, French, English and Dutch trading posts multiplied in northern America to exploit whaling, fishing and fur trading. French settlements progressed up the St Lawrence river to the Great Lakes and down
1903-532: A definition of Indigenous peoples stating that, "such a definition is not necessary for purposes of protecting their human rights." In determining coverage of Indigenous peoples, the commission uses the criteria developed in documents such as ILO Convention No. 169 and the United Nations Declaration on the Rights of Indigenous Peoples. The commission states that self-identification as indigenous
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#17327648565122076-491: A deliberate strategy in defending their claims against European rivals. Although the establishment of colonies throughout the world by various European powers aimed to expand those powers' wealth and influence, settler populations in some localities became anxious to assert their own autonomy. For example, settler independence movements in thirteen of the British American colonies were successful by 1783, following
2249-413: A dozen men about fifty feet away from the deck of Primrose. We were skeptical and scared and had no other solution but to bring out our supply of bananas and show it to them to attract them and minimize any chance of hostility. They took the bananas and came up on board of Primrose and were frantically looking around for smaller pieces of metal scrap [...] They visited us regularly at least twice or thrice in
2422-405: A forgotten member of itself, of another Andamanese tribe, or a complete foreigner". Other British colonial administrators visited the island, including Rogers in 1902, but none of the expeditions after 1880 had any ethnographic purpose, probably because of the island's small size and unfavourable location. M.C.C. Bonnington, a British colonial official, visited the island in 1911 and 1932 to conduct
2595-549: A large quantity of gifts in an attempt to establish friendly relations. Portman visited the island again in 1883, 1885 and 1887. In 1896, a convict escaped from the penal colony on Great Andaman Island on a makeshift raft and drifted across to the North Sentinel beach. His body was discovered by a search party some days later with several arrow-piercings and a cut throat. The party recorded that they did not see any islanders. In an 1899 speech, Richard Carnac Temple , who
2768-465: A mixture of amusement, bewilderment, and hostility. He attempted to sing worship songs to them, and spoke to them in Xhosa , after which they often fell silent, while other attempts to communicate ended with them bursting into laughter. Chau said the Sentinelese communicated with "lots of high pitched sounds" and gestures. Eventually, according to Chau's last letter, when he tried to hand over fish and gifts,
2941-424: A month while we worked at the site for about 18 months. In 1991, the first instances of peaceful contact were recorded in the course of two routine expeditions by an Indian anthropological team consisting of various representatives of diverse governmental departments, including the anthropologist Madhumala Chattopadhyay . This was the first time a woman was a part of a contact expedition with the Sentinelese. During
3114-625: A particular place – indeed how we/they came to be a place. Our/their relationships to land comprise our/their epistemologies, ontologies, and cosmologies". Indigenous peoples such as the Maasai and the Māori have oral traditional histories involving migration to their current location from somewhere else. Anthropologist Manvir Singh states that the term may lack coherence, pointing to inconsistencies in which ethnic groups are called Indigenous or not, and notes several scholars who suggest that it instead acts as
3287-430: A policy of no deliberate contact, intervening only in cases of natural calamities that might pose an existential threat or to thwart poachers. A likely reason for the termination of these missions was that the Sentinelese did not let most of the post-Pandit contact teams get near them. The teams usually waited until the armed Sentinelese retreated, then left gifts on the beach or set them adrift toward shore. The government
3460-441: A probable cause for it being soft with a low melting point and low electrical resistivity . Aluminium metal has an appearance ranging from silvery white to dull gray depending on its surface roughness . Aluminium mirrors are the most reflective of all metal mirrors for near ultraviolet and far infrared light. It is also one of the most reflective for light in the visible spectrum, nearly on par with silver in this respect, and
3633-683: A process termed passivation . Because of its general resistance to corrosion, aluminium is one of the few metals that retains silvery reflectance in finely powdered form, making it an important component of silver-colored paints. Aluminium is not attacked by oxidizing acids because of its passivation. This allows aluminium to be used to store reagents such as nitric acid , concentrated sulfuric acid , and some organic acids. In hot concentrated hydrochloric acid , aluminium reacts with water with evolution of hydrogen, and in aqueous sodium hydroxide or potassium hydroxide at room temperature to form aluminates —protective passivation under these conditions
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#17327648565123806-435: A protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver , both in its color and in its great ability to reflect light. It is soft, nonmagnetic , and ductile . It has one stable isotope, Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of Al leads to it being used in radiometric dating . Chemically, aluminium
3979-525: A refractory material, and in ceramics , as well as being the starting material for the electrolytic production of aluminium. Sapphire and ruby are impure corundum contaminated with trace amounts of other metals. The two main oxide-hydroxides, AlO(OH), are boehmite and diaspore . There are three main trihydroxides: bayerite , gibbsite , and nordstrandite , which differ in their crystalline structure ( polymorphs ). Many other intermediate and related structures are also known. Most are produced from ores by
4152-536: A relabeling of discredited and colonial ideas about "primitive" people. Singh states that some Indigenous people argue that the term and identity has resulted in pressure to appear "primordial" and "unchanging", and erases complex and modern identities. Other views It is sometimes argued that all Africans are Indigenous to Africa, all Asians are Indigenous to parts of Asia, or that there can be no Indigenous peoples in countries which did not experience large-scale Western settler colonialism. Many countries have avoided
4325-482: A rifle hidden in the boat, which Chattopadhyay believed they saw as a source of iron. In light of the friendly exchanges with the scrap dealers' team and Portman's observations in 1880, Pandya believes that the Sentinelese used to be visited by other tribes. The series of contact expeditions continued until 1994, with some of them even attempting to plant coconut trees on the island. The programmes were then abandoned for nearly nine years. The Indian government maintained
4498-456: A scrap dealer who won a government contract to dismantle the Primrose wreck (about 90 m [300 ft] from the shoreline) and assembled men for the purpose, recorded friendly exchange of fruits and small metal scraps with the Sentinelese, who often canoed to the workplace at low tide: After two days, in the early morning when it was low tide we saw three Sentinelese canoes with about
4671-474: A stable noble gas configuration. Accordingly, the combined first three ionization energies of aluminium are far lower than the fourth ionization energy alone. Such an electron configuration is shared with the other well-characterized members of its group, boron , gallium , indium , and thallium ; it is also expected for nihonium . Aluminium can surrender its three outermost electrons in many chemical reactions (see below ). The electronegativity of aluminium
4844-488: A state, a special relationship with their traditional territory, and an experience of subjugation and discrimination under a dominant cultural model. No definition of Indigenous peoples has been adopted by a United Nations agency. The Secretariat of the Permanent Forum on Indigenous Issues states, "in the case of the concept of 'indigenous peoples', the prevailing view today is that no formal universal definition of
5017-458: A team of anthropologists (including Pandit), accompanied by armed police, to film a documentary, Man in Search of Man . They planned to spread the operation of gift-giving over three days and attempt to establish friendly contact. When the motorboat broke through the barrier reefs, the locals emerged from the jungle and shot arrows at it. The crew landed at a safe point on the coast and left gifts in
5190-417: A tribal reserve and prohibited travel within 3 nautical miles (5.6 kilometres) of it. It further maintains a constant armed patrol in the surrounding waters to prevent intrusions by outsiders. Photography is prohibited. There is significant uncertainty as to the group's size, with estimates ranging between 35 and 500 individuals, but mostly between 50 and 200. The Sentinelese live on North Sentinel Island , in
5363-484: A tribal reserve and prohibited travel within 3 nautical miles (5.6 kilometres). Photography was prohibited. A constant armed patrol prevents intrusions by outsiders. The Sentinelese are a community of indigenous peoples in voluntary isolation . Designated a particularly vulnerable tribal group and a Scheduled Tribe , they belong to the broader class of Andamanese people . Along with the Great Andamanese,
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5536-567: A tropical climate. A 1977 report by Heinrich Harrer described a man as 1.60 metres (5 ft 3 in) tall, possibly because of insular dwarfism (the so-called "Island Effect"), nutrition, or simply genetic heritage. During a 2014 circumnavigation of their island, researchers put their height between 1.60 and 1.65 m (5 ft 3 in and 5 ft 5 in) and recorded their skin colour as "dark, shining black" with well-aligned teeth. They showed no signs of obesity and had very prominent muscles. No rigorous census has been conducted and
5709-820: A variety of wet processes using acid and base. Heating the hydroxides leads to formation of corundum. These materials are of central importance to the production of aluminium and are themselves extremely useful. Some mixed oxide phases are also very useful, such as spinel (MgAl 2 O 4 ), Na-β-alumina (NaAl 11 O 17 ), and tricalcium aluminate (Ca 3 Al 2 O 6 , an important mineral phase in Portland cement ). The only stable chalcogenides under normal conditions are aluminium sulfide (Al 2 S 3 ), selenide (Al 2 Se 3 ), and telluride (Al 2 Te 3 ). All three are prepared by direct reaction of their elements at about 1,000 °C (1,800 °F) and quickly hydrolyze completely in water to yield aluminium hydroxide and
5882-575: A way of purifying bauxite to yield alumina, now known as the Bayer process , in 1889. Modern production of aluminium is based on the Bayer and Hall–Héroult processes. As large-scale production caused aluminium prices to drop, the metal became widely used in jewelry, eyeglass frames, optical instruments, tableware, and foil , and other everyday items in the 1890s and early 20th century. Aluminium's ability to form hard yet light alloys with other metals provided
6055-734: Is Al : while it was present along with stable Al in the interstellar medium from which the Solar System formed, having been produced by stellar nucleosynthesis as well, its half-life is only 717,000 years and therefore a detectable amount has not survived since the formation of the planet. However, minute traces of Al are produced from argon in the atmosphere by spallation caused by cosmic ray protons. The ratio of Al to Be has been used for radiodating of geological processes over 10 to 10 year time scales, in particular transport, deposition, sediment storage, burial times, and erosion. Most meteorite scientists believe that
6228-434: Is Al. Al was present in the early Solar System with abundance of 0.005% relative to Al but its half-life of 728,000 years is too short for any original nuclei to survive; Al is therefore extinct . Unlike for Al, hydrogen burning is the primary source of Al, with the nuclide emerging after a nucleus of Mg catches a free proton. However, the trace quantities of Al that do exist are the most common gamma ray emitter in
6401-407: Is paramagnetic and thus essentially unaffected by static magnetic fields. The high electrical conductivity, however, means that it is strongly affected by alternating magnetic fields through the induction of eddy currents . Aluminium combines characteristics of pre- and post-transition metals. Since it has few available electrons for metallic bonding, like its heavier group 13 congeners, it has
6574-483: Is 1.61 (Pauling scale). 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 (when not affected by atoms of other elements) form a face-centered cubic crystal system bound by metallic bonding provided by atoms' outermost electrons; hence aluminium (at these conditions)
6747-418: Is a post-transition metal in the boron group ; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state . The aluminium cation Al is small and highly charged ; as such, it has more polarizing power , and bonds formed by aluminium have a more covalent character. The strong affinity of aluminium for oxygen leads to the common occurrence of its oxides in nature. Aluminium
6920-539: Is a fundamental criterion. The World Bank states, "Indigenous Peoples are distinct social and cultural groups that share collective ancestral ties to the lands and natural resources where they live, occupy or from which they have been displaced." Amnesty International does not provide a definition of Indigenous peoples but states that they can be identified according to certain characteristics: Academics and other scholars have developed various definitions of Indigenous peoples. In 1986–87, José Martínez Cobo, developed
7093-548: Is a metal. This crystal system is shared by many other metals, such as lead and copper ; the size of a unit cell of aluminium is comparable to that of those other metals. The system, however, is not shared by the other members of its group: boron has ionization energies too high to allow metallization, thallium has a hexagonal close-packed structure, and gallium and indium have unusual structures that are not close-packed like those of aluminium and thallium. The few electrons that are available for metallic bonding in aluminium are
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7266-522: Is almost never found in the elemental state; instead it is found in oxides or silicates. Feldspars , the most common group of minerals in the Earth's crust, are aluminosilicates. Aluminium also occurs in the minerals beryl , cryolite , garnet , spinel , and turquoise . Impurities in Al 2 O 3 , such as chromium and iron , yield the gemstones ruby and sapphire , respectively. Native aluminium metal
7439-405: Is also easily machined and cast . Aluminium is an excellent thermal and electrical conductor , having around 60% 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 (10 milliteslas ). It
7612-553: Is extremely rare and can only be found as a minor phase in low oxygen fugacity environments, such as the interiors of certain volcanoes. Native aluminium has been reported in cold seeps in the northeastern continental slope of the South China Sea . It is possible that these deposits resulted from bacterial reduction of tetrahydroxoaluminate Al(OH) 4 . Although aluminium is a common and widespread element, not all aluminium minerals are economically viable sources of
7785-438: Is found on Earth primarily in rocks in the crust , where it is the third-most abundant element , after oxygen and silicon , rather than in the mantle , and virtually never as the free metal . It is obtained industrially by mining bauxite , a sedimentary rock rich in aluminium minerals. The discovery of aluminium was announced in 1825 by Danish physicist Hans Christian Ørsted . The first industrial production of aluminium
7958-536: Is greatly reduced by aqueous salts, particularly in the presence of dissimilar metals. Aluminium reacts with most nonmetals upon heating, forming compounds such as aluminium nitride (AlN), aluminium sulfide (Al 2 S 3 ), and the aluminium halides (AlX 3 ). It also forms a wide range of intermetallic compounds involving metals from every group on the periodic table. The vast majority of compounds, including all aluminium-containing minerals and all commercially significant aluminium compounds, feature aluminium in
8131-492: Is in fact more basic than that of gallium. Aluminium also bears minor similarities to the metalloid boron in the same group: AlX 3 compounds are valence isoelectronic to BX 3 compounds (they have the same valence electronic structure), and both behave as Lewis acids and readily form adducts . Additionally, one of the main motifs of boron chemistry is regular icosahedral structures, and aluminium forms an important part of many icosahedral quasicrystal alloys, including
8304-530: Is known about the Sentinelese language, which is therefore unclassified . It has been recorded that the Jarawa language is mutually unintelligible with the Sentinelese language. The range of overlap with the Onge language is unknown; the Anthropological Survey of India 's 2016 handbook on Vulnerable Tribe Groups considers them mutually unintelligible. In 1957, the Indian government declared North Sentinel Island
8477-500: Is negligible. Aqua regia also dissolves aluminium. Aluminium is corroded by dissolved chlorides , such as common sodium chloride , which is why household plumbing is never made from aluminium. The oxide layer on aluminium is also destroyed by contact with mercury due to amalgamation or with salts of some electropositive metals. As such, the strongest aluminium alloys are less corrosion-resistant due to galvanic reactions with alloyed copper , and aluminium's corrosion resistance
8650-466: Is no generally accepted definition of Indigenous peoples in the United Nations or international law. Various national and international organizations, non-government organizations, governments, Indigenous groups and scholars have developed definitions or have declined to provide a definition. As a reference to a group of people, the term "indigenous" was first used by Europeans to differentiate
8823-521: Is not as important. It is a polymer with the formula (AlH 3 ) n , in contrast to the corresponding boron hydride that is a dimer with the formula (BH 3 ) 2 . Aluminium's per-particle abundance in the Solar System is 3.15 ppm (parts per million). It is the twelfth most abundant of all elements and third most abundant among the elements that have odd atomic numbers, after hydrogen and nitrogen. The only stable isotope of aluminium, Al,
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#17327648565128996-416: Is quite soft and lacking in strength. In most applications various aluminium alloys are used instead because of their higher strength and hardness. The yield strength of pure aluminium is 7–11 MPa , while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium is ductile , with a percent elongation of 50-70%, and malleable allowing it to be easily drawn and extruded . It
9169-608: Is rarely used in Europe, where very few indigenous groups are recognized, with the exception of groups such as the Sámi . Aluminium Aluminium (or aluminum in North American English ) is a chemical element ; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals , about one-third that of steel . It has a great affinity towards oxygen , forming
9342-422: Is surrounded by six fluorine atoms in a distorted octahedral arrangement, with each fluorine atom being shared between the corners of two octahedra. Such {AlF 6 } units also exist in complex fluorides such as cryolite , Na 3 AlF 6 . AlF 3 melts at 1,290 °C (2,354 °F) and is made by reaction of aluminium oxide with hydrogen fluoride gas at 700 °C (1,300 °F). With heavier halides,
9515-547: Is termed amphoterism and is characteristic of weakly basic cations that form insoluble hydroxides and whose hydrated species can also donate their protons. One effect of this is that aluminium salts with weak acids are hydrolyzed in water to the aquated hydroxide and the corresponding nonmetal hydride: for example, aluminium sulfide yields hydrogen sulfide . However, some salts like aluminium carbonate exist in aqueous solution but are unstable as such; and only incomplete hydrolysis takes place for salts with strong acids, such as
9688-416: Is that of the preceding noble gas , whereas those of its heavier congeners gallium , indium , thallium , and nihonium also include a filled d-subshell and in some cases a filled f-subshell. Hence, the inner electrons of aluminium shield the valence electrons almost completely, unlike those of aluminium's heavier congeners. As such, aluminium is the most electropositive metal in its group, and its hydroxide
9861-433: Is the eighteenth most abundant nucleus in the universe. It is created almost entirely after fusion of carbon in massive stars that will later become Type II supernovas : this fusion creates Mg, which upon capturing free protons and neutrons, becomes aluminium. Some smaller quantities of Al are created in hydrogen burning shells of evolved stars, where Mg can capture free protons. Essentially all aluminium now in existence
10034-411: Is well tolerated by plants and animals. Because of the abundance of these salts, the potential for a biological role for them is of interest, and studies are ongoing. Of aluminium isotopes, only Al is stable. This situation is common for elements with an odd atomic number. It is the only primordial aluminium isotope, i.e. the only one that has existed on Earth in its current form since
10207-751: The American Revolutionary War . This resulted in the establishment of the United States of America as an entity separate from the British Empire . The United States continued and expanded European colonial doctrine through adopting a version of the discovery doctrine as law in 1823 with the US Supreme Court case Johnson v. McIntosh . Statements at the Johnson court case illuminated the United States' support for
10380-488: The Andaman Islands , an Indian archipelago in the Bay of Bengal . The island lies about 64 km (35 nmi) west of Andaman capital Port Blair . It has an area of about 59.67 km (14,740 acres) and a roughly square outline. The seashore is about 45 m (50 yd) wide, bordered by a littoral forest that gives way to a dense tropical evergreen forest . The island is surrounded by coral reefs and has
10553-569: The Diligent , observed "a multitude of lights [...] upon the shore" of North Sentinel Island, which is the island's first recorded mention. The crew did not investigate. During a late summer monsoon in October 1867, the Indian merchant-vessel Nineveh foundered on the reef off North Sentinel. All the passengers and crew reached the beach safely, but as they proceeded for their breakfast on
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#173276485651210726-455: The Friedel–Crafts reactions . Aluminium trichloride has major industrial uses involving this reaction, such as in the manufacture of anthraquinones and styrene ; it is also often used as the precursor for many other aluminium compounds and as a reagent for converting nonmetal fluorides into the corresponding chlorides (a transhalogenation reaction ). Aluminium forms one stable oxide with
10899-475: The London Metal Exchange , the oldest industrial metal exchange in the world, in 1978. The output continued to grow: the annual production of aluminium exceeded 50,000,000 metric tons in 2013. The real price for aluminium declined from $ 14,000 per metric ton in 1900 to $ 2,340 in 1948 (in 1998 United States dollars). Extraction and processing costs were lowered over technological progress and
11072-582: The Shompen , and the Nicobarese , the Sentinelese are one of the six native and often reclusive peoples of the Andaman and Nicobar Islands . The tribe has had minimal contact with outsiders and has usually been hostile to those who approach or land on the island. While friendly contact was reported in the early 1990s, such instances are rare. In 1956, the government of India declared North Sentinel Island
11245-617: The United Nations Working Group on Indigenous Populations (WGIP) was on 9 August 1982 and this date is now celebrated as the International Day of the World's Indigenous Peoples . In the 21st century, the concept of Indigenous peoples is understood in a wider context than only the colonial experience. The focus has been on self-identification as indigenous peoples, cultural difference from other groups in
11418-475: The aluminum spelling in his American Dictionary of the English Language . In the 1830s, the -um spelling gained usage in the United States; by the 1860s, it had become the more common spelling there outside science. In 1892, Hall used the -um spelling in his advertising handbill for his new electrolytic method of producing the metal, despite his constant use of the -ium spelling in all
11591-423: The chemical formula Al 2 O 3 , commonly called alumina . It can be found in nature in the mineral corundum , α-alumina; there is also a γ-alumina phase. Its crystalline form, corundum, is very hard ( Mohs hardness 9), has a high melting point of 2,045 °C (3,713 °F), has very low volatility, is chemically inert, and a good electrical insulator, it is often used in abrasives (such as toothpaste), as
11764-551: The interstellar gas ; if the original Al were still present, gamma ray maps of the Milky Way would be brighter. Overall, the Earth is about 1.59% aluminium by mass (seventh in abundance by mass). Aluminium occurs in greater proportion in the Earth's crust than in the universe at large. This is because aluminium easily forms the oxide and becomes bound into rocks and stays in the Earth's crust , while less reactive metals sink to
11937-519: The 10th century, however, the majority of the population of north Africa spoke Arabic and practiced Islam. From 1402, the Guanche of the Canary Islands resisted Spanish attempts at colonization. The islands finally came under Spanish control in 1496. Mohamed Adhikari has called the conquest of the islands a genocide . Early 15th-century Portuguese exploration of the west coast of Africa
12110-572: The 17th and 18th centuries, had extensive contact with Europeans when the continent was progressively colonized by the British from 1788. During colonization, the Aboriginal people experienced depopulation from disease and settler violence, dispossession of their land, and severe disruption of their traditional cultures. By 1850, indigenous peoples were a minority in Australia. From the 15th to
12283-471: The 1911 census. In 1954, the Italian explorer Lidio Cipriani visited the island but did not encounter any inhabitants. In 1967, a group of 20 people, comprising the governor, armed forces and naval personnel, were led by T. N. Pandit , an Indian anthropologist working for the Anthropological Survey of India , to North Sentinel Island to explore it and befriend the Sentinelese. This was the first visit to
12456-496: The 1991 contact, which had already been taken out of public display, and restored the 1975 National Geographic narrative. In November 2018, John Allen Chau , a 26-year-old American trained and sent by the US-based Christian missionary organization All Nations, travelled to North Sentinel Island with the aim of contacting and living among the Sentinelese in the hope of converting them to Christianity. He did not seek
12629-636: The 19th centuries, European powers used a number of rationales for the colonization of newly encountered lands populated by indigenous peoples. These included a duty to spread the Gospel to non-Christians, to bring civilization to barbarian peoples, a natural law right to explore and trade freely with other peoples, and a right to settle and cultivate uninhabited or uncultivated land which they considered terra nullius ("no one's land"). Robert J. Miller, Jacinta Ruru, Larissa Behrendt and Tracey Lindberg argue that European powers rationalized their colonization of
12802-463: The 21st century the focus has been on self-identification, cultural difference from other groups in a state, a special relationship with their traditional territory, and an experience of subjugation and discrimination under a dominant cultural model. Estimates of the population of Indigenous peoples range from 250 million to 600 million. There are some 5,000 distinct Indigenous peoples spread across every inhabited climate zone and inhabited continent of
12975-625: The 21st century, Indigenous groups and advocates for Indigenous peoples have highlighted numerous apparent violations of the rights of Indigenous peoples. Indigenous is derived from the Latin word indigena , meaning "sprung from the land, native". The Latin indigena is based on the Old Latin indu "in, within" + gignere "to beget, produce". Indu is an extended form of the Proto-Indo-European en or "in". There
13148-526: The 5th century BCE. The ancients are known to have used alum as a dyeing mordant and for city defense. After the Crusades , alum, an indispensable good in the European fabric industry, was a subject of international commerce; it was imported to Europe from the eastern Mediterranean until the mid-15th century. The nature of alum remained unknown. Around 1530, Swiss physician Paracelsus suggested alum
13321-472: The Al–Zn–Mg class. Aluminium has a high chemical affinity to oxygen, which renders it suitable for use as a reducing agent in the thermite reaction. A fine powder of aluminium reacts explosively on contact with liquid oxygen ; under normal conditions, however, aluminium forms a thin oxide layer (~5 nm at room temperature) that protects the metal from further corrosion by oxygen, water, or dilute acid,
13494-551: The Aztec Empire and its fall. The Cempoalans, Tlaxcalans and other allies of the Spanish were given some autonomy, but the Spanish were de facto rulers of Mexico. Smallpox devastated the indigenous population and aided the Spanish conquest. In 1530, the Spanish sailed south from Panama to the lands of the Inca Empire in the west of South America. The Inca, weakened by a smallpox epidemic and civil war, were defeated by
13667-520: The Bahamas and Cuba, leading to a severe decline in the Indigenous populations from disease, malnutrition, settler violence and cultural disruption. In the 1520s, the peoples of Mesoamerica encountered the Spanish who entered their lands in search of gold and other resources. Some indigenous peoples chose to ally with the Spanish to end Aztec rule. The Spanish incursions led to the conquest of
13840-621: The French. The indigenous inhabitants of the Hawaiian Islands first encountered Europeans in 1778 when Cook explored the region. Following increasing contact with European missionaries, traders and scientific expeditions, the indigenous population fell before their lands were annexed by the United States in 1893. The Māori of New Zealand also had sporadic encounters with Europeans in the 17th and 18th centuries. Following encounters with Cook's exploration parties in 1769–70, New Zealand
14013-510: The Indigenous peoples of the Americas from enslaved Africans. The first known use was by Sir Thomas Browne in 1646, who wrote "and although in many parts thereof there be at present swarms of Negroes serving under the Spaniard , yet were they all transported from Africa , since the discovery of Columbus ; and are not indigenous or proper natives of America ." In the 1970s, the term
14186-624: The Jarawas, the Onge, the Shompen, and the Nicobarese, the Sentinelese are one of the six native and often reclusive peoples of the Andaman and Nicobar Islands . Unlike the others, the Sentinelese appear to have consistently refused any interaction with the outside world. They are hostile to outsiders and have killed people who approached or landed on the island. The first peaceful contact with
14359-671: The Mississippi to Louisiana. English and Dutch settlements multiplied down the Atlantic coast from modern Massachusetts to Georgia. Native peoples formed alliances with the Europeans in order to promote trade, preserve their autonomy, and gain allies in conflicts with other native peoples. However, horses and new weapons made inter-tribal conflicts more deadly and the native population was devastated by introduced diseases. Native peoples also experienced losses from violent conflict with
14532-648: The New World by the discovery doctrine , which they trace back to papal decrees authorizing Spain and Portugal to conquer newly discovered non-Christian lands and convert their populations to Christianity. Kent McNeil, however, states, "While Spain and Portugal favoured discovery and papal grants because it was generally in their interests to do so, France and Britain relied more on symbolic acts, colonial charters, and occupation." Benton and Strauman argue that European powers often adopted multiple, sometimes contradictory, legal rationales for their acquisition of territory as
14705-506: The New World. In 1488, Portuguese ships rounded the Cape of Good Hope and by the 17th century, Portugal had established seaborn trading routes and fortified coastal trading posts from West Africa to India and Southern China, and a settler colony in Brazil. In 1532, the first African slaves were transported directly to the Americas. The trade in slaves expanded sharply in the 17th century, with
14878-425: The Sentinelese during the gift giving exercise. Every participating member of the contact party wanted to take the credit of being the first to 'touch the Sentinelese', as if it were a great mystical moment of transubstantiation wherein the savage hostile reciprocated a gesture of civilized friendship. Who touched and who was touched during the contact event became an emotionally charged issue within various sectors of
15051-418: The Sentinelese was made by Triloknath Pandit , a director of the Anthropological Survey of India , and his colleagues, on 4 January 1991. Later, contact was made by Madhumala Chattopadhyay. Indian visits to the island ceased in 1997. An American, John Allen Chau , was killed in 2018 while visiting the island illegally as a Christian missionary. In 1771, an East India Company hydrographic survey vessel,
15224-526: The Spanish at Cajamarca in 1532, and the emperor Atahualpa was captured and executed. The Spanish appointed a puppet emperor and captured the Inca capital of Cuzco with the support of a number of native peoples. The Spanish established a new capital in 1535 and defeated an Inca rebellion in 1537, thus consolidating the conquest of Peru. In the 1560s, the Spanish established colonies in Florida and in 1598 founded
15397-447: The United Nations (UN) adopted a Declaration on the Rights of Indigenous Peoples including their rights to self-determination and to protect their cultures, identities, languages, ceremonies, and access to employment, health, education and natural resources. Indigenous peoples continue to face threats to their sovereignty, economic well-being, languages, cultural heritage, and access to the resources on which their cultures depend. In
15570-418: The United States dollar, and alumina prices. The BRIC countries' combined share in primary production and primary consumption grew substantially in the first decade of the 21st century. China is accumulating an especially large share of the world's production thanks to an abundance of resources, cheap energy, and governmental stimuli; it also increased its consumption share from 2% in 1972 to 40% in 2010. In
15743-514: The United States, Western Europe, and Japan, most aluminium was consumed in transportation, engineering, construction, and packaging. In 2021, prices for industrial metals such as aluminium have soared to near-record levels as energy shortages in China drive up costs for electricity. The names aluminium and aluminum are derived from the word alumine , an obsolete term for alumina , the primary naturally occurring oxide of aluminium . Alumine
15916-399: The abundance of roasted shells found in their settlements. They are not known to engage in agriculture . Both sexes wear bark strings; the men tuck daggers into their waist belts. They also wear some ornaments such as necklaces and headbands, but are essentially nude. Usual habitations include small temporary huts erected on four poles with slanted leaf-covered roofs . Sentinelese appreciate
16089-431: The administration where claims and counter-claims were sought to be established with earnestness and vigor ... it is interesting to note the range of political and cultural significance invested in this specific event of contact. Pandit and Madhumala took part in a second expedition on 24 February. The Sentinelese again appeared without weapons, jumped on the dinghies and took coconut sacks. They were also curious about
16262-578: The aluminium atoms have tetrahedral four-coordination and the other half have trigonal bipyramidal five-coordination. Four pnictides – aluminium nitride (AlN), aluminium phosphide (AlP), aluminium arsenide (AlAs), and aluminium antimonide (AlSb) – are known. They are all III-V semiconductors isoelectronic to silicon and germanium , all of which but AlN have the zinc blende structure. All four can be made by high-temperature (and possibly high-pressure) direct reaction of their component elements. Aluminium alloys well with most other metals (with
16435-564: The ancestors of the Greeks , or as an earlier group of people who inhabited Greece before the Greeks. The disposition and precise identity of this former group is elusive, and sources such as Homer , Hesiod and Herodotus give varying, partially mythological accounts. Dionysius of Halicarnassus in his book, Roman Antiquities , gives a synoptic interpretation of the Pelasgians based on
16608-445: The basis of their continued existence as peoples, in accordance with their own cultural patterns, social institutions and legal systems. Martínez Cobo states that the following factors are relevant to historical continuity: occupation of ancestral lands, or at least of part of them; common ancestry with the original occupants of these lands; cultural factors such as religion, tribalism, dress, etc.; language; residence in certain parts of
16781-491: The canoes for cross-island navigation. Artistic engravings of simple geometric designs and shade contrasts have been seen on their weapons. The women have been seen to dance by slapping both palms on the thighs whilst simultaneously tapping the feet rhythmically in a bent-knee stance. Similarities and dissimilarities to the Onge people have been noted. They prepare their food similarly. They share common traits in body decoration and material culture. There are also similarities in
16954-436: The characteristic physical properties of a post-transition metal, with longer-than-expected interatomic distances. Furthermore, as Al is a small and highly charged cation, it is strongly polarizing and bonding in aluminium compounds tends towards covalency ; this behavior is similar to that of beryllium (Be ), and the two display an example of a diagonal relationship . The underlying core under aluminium's valence shell
17127-685: The circumstances of the people would allow them to exercise. ... [This loss of native property and sovereignty rights was justified, the Court said, by] the character and religion of its inhabitants ... the superior genius of Europe ... [and] ample compensation to the [Indians] by bestowing on them civilization and Christianity, in exchange for unlimited independence. Estimates of the population of Indigenous peoples range from 250 million to 600 million. The United Nations estimates that there are over 370 million Indigenous people living in over 90 countries worldwide. This would equate to just fewer than 6% of
17300-737: The colonists and the progressive dispossession of their traditional lands. In 1492, the population of the Americas as a whole was about 50 to 100 million. By 1700, introduced diseases had reduced the native population by 90%. European migration and transfer of slaves from Africa reduced the native population to a minority. By 1800 the population of North America comprised about 5 million Europeans and their descendants, one million Africans and 600,000 indigenous Americans. Native populations also encountered new animals and plants introduced by Europeans. These included pigs, horses, mules, sheep and cattle; wheat, barley, rye, oats, grasses and grapevines. These exotic animals and plants radically transformed
17473-560: The community was mostly unaffected and had survived the calamity. Pandya argues that Sentinelese hostility is a sign of the physical as well as the cultural resilience of the community. The Sentinelese generally received the post-tsunami expeditions in a friendly manner. They approached the visiting parties unarmed, in contrast to the arms or shields carried when meeting earlier expeditions. On 27 January 2006, Indian fishermen Sunder Raj and Pandit Tiwari, who had been attempting to illegally harvest crabs off North Sentinel Island, drifted towards
17646-678: The convention covers: peoples in independent countries who are regarded as indigenous on account of their descent from the populations which inhabited the country, or a geographical region to which the country belongs, at the time of conquest or colonisation or the establishment of present state boundaries and who, irrespective of their legal status, retain some or all of their own social, economic, cultural and political institutions. The convention also covers "tribal peoples" who are distinguished from Indigenous peoples and described as "tribal peoples in independent countries whose social, cultural and economic conditions distinguish them from other sections of
17819-419: The coordination numbers are lower. The other trihalides are dimeric or polymeric with tetrahedral four-coordinate aluminium centers. Aluminium trichloride (AlCl 3 ) has a layered polymeric structure below its melting point of 192.4 °C (378 °F) but transforms on melting to Al 2 Cl 6 dimers. At higher temperatures those increasingly dissociate into trigonal planar AlCl 3 monomers similar to
17992-428: The core. In the Earth's crust, aluminium is the most abundant metallic element (8.23% by mass ) and the third most abundant of all elements (after oxygen and silicon). A large number of silicates in the Earth's crust contain aluminium. In contrast, the Earth's mantle is only 2.38% aluminium by mass. Aluminium also occurs in seawater at a concentration of 2 μg/kg. Because of its strong affinity for oxygen, aluminium
18165-485: The corners of the hut. The team also discovered raw honey, skeletal remains of pigs, wild fruits, an adze , a multi-pronged wooden spear, bows, arrows, cane baskets, fishing nets, bamboo pots and wooden buckets. Metal-working was evident. The team failed to establish any contact and withdrew after leaving gifts. The government was aware that leaving the Sentinelese (and the area) completely isolated and ceasing to claim any control would lead to rampant illegal exploitation of
18338-541: The country, or in certain regions of the world; and other relevant factors. In 2004, James Anaya , defined Indigenous peoples as "living descendants of pre-invasion inhabitants of lands now dominated by others. They are culturally distinct groups that find themselves engulfed by other settler societies born of forces of empire and conquest". In 2012, Tuck and Yang propose a criterion based on accounts of origin: "Indigenous peoples are those who have creation stories, not colonization stories, about how we/they came to be in
18511-520: The design of their canoes; of all the Andamanese tribes, only the Sentinelese and Onge make canoes. Similarities with the Jarawas have been also noted: their bows have similar patterns. No such marks are found on Onge bows, and both tribes sleep on the ground, while the Onge sleep on raised platforms. The metal arrowheads and adze blades are quite large and heavier than those of other Andamanese tribes. Because of their complete isolation, nearly nothing
18684-559: The effects of the 2004 Indian Ocean tsunami , which caused massive tectonic changes to the island: it was enlarged by a merger with nearby small islands, and the sea floor was raised by about 1.5 m (4 ft 11 in), exposing the surrounding coral reefs to air and destroying the shallow lagoons, which were the Sentinelese's fishing grounds. The expeditions counted 32 Sentinelese scattered over three places but did not find any bodies. The Sentinelese responded to these aerial expeditions with hostile gestures, which led many to conclude that
18857-497: The energy released by the decay of Al 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 [ Ne ] 3s 3p , with three electrons beyond
19030-478: The exception of most alkali metals and group 13 metals) and over 150 intermetallics with other metals are known. Preparation involves heating fixed metals together in certain proportion, followed by gradual cooling and annealing . Bonding in them is predominantly metallic and the crystal structure primarily depends on efficiency of packing. There are few compounds with lower oxidation states. A few aluminium(I) compounds exist: AlF, AlCl, AlBr, and AlI exist in
19203-579: The exploitation of natural resources, spreading Christianity, and establishing strategic military bases, colonies and settlements. From 1492, the Arawak peoples of the Caribbean islands encountered Spanish colonizers initially led by Christopher Columbus . The Spanish enslaved some of the native population and forced others to work on farms and gold mines in a system of labor called encomienda . Spanish settlements spread from Hispaniola to Puerto Rico,
19376-520: The fact that its nuclei are much lighter, while difference in the unit cell size does not compensate for this difference. The only lighter metals are the metals of groups 1 and 2 , which apart from beryllium and magnesium are too reactive for structural use (and beryllium is very toxic). Aluminium is not as strong or stiff as steel, but the low density makes up for this in the aerospace industry and for many other applications where light weight and relatively high strength are crucial. Pure aluminium
19549-507: The first photograph of the Sentinelese, published by Raghubir Singh in National Geographic magazine, where they were presented as people for whom "arrows speak louder than words". During the 1970s and 1980s, Pandit undertook several visits to the island, sometimes as an "expert advisor" in tour parties including dignitaries who wished to encounter an aboriginal tribe. Beginning in 1981, he regularly led official expeditions with
19722-524: The following "working definition" : Indigenous communities, peoples, and nations are those that, having a historical continuity with pre-invasion and pre-colonial societies that developed on their territories, consider themselves distinct from other sectors of the societies now prevailing in those territories, or parts of them. They form at present non-dominant sectors of society and are determined to preserve, develop, and transmit to future generations their ancestral territories, and their ethnic identity, as
19895-442: The formation of the planet. It is therefore a mononuclidic element and its standard atomic weight is virtually the same as that of the isotope. This makes aluminium very useful in nuclear magnetic resonance (NMR), as its single stable isotope has a high NMR sensitivity. The standard atomic weight of aluminium is low in comparison with many other metals. All other isotopes of aluminium are radioactive . The most stable of these
20068-730: The gas phase after explosion and in stellar absorption spectra. More thoroughly investigated are compounds of the formula R 4 Al 2 which contain an Al–Al bond and where R is a large organic ligand . A variety of compounds of empirical formula AlR 3 and AlR 1.5 Cl 1.5 exist. The aluminium trialkyls and triaryls are reactive, volatile, and colorless liquids or low-melting solids. They catch fire spontaneously in air and react with water, thus necessitating precautions when handling them. They often form dimers, unlike their boron analogues, but this tendency diminishes for branched-chain alkyls (e.g. Pr , Bu , Me 3 CCH 2 ); for example, triisobutylaluminium exists as an equilibrium mixture of
20241-453: The gaseous phase when the respective trihalide is heated with aluminium, and at cryogenic temperatures. A stable derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine , Al 4 I 4 (NEt 3 ) 4 . Al 2 O and Al 2 S also exist but are very unstable. Very simple aluminium(II) compounds are invoked or observed in the reactions of Al metal with oxidants. For example, aluminium monoxide , AlO, has been detected in
20414-646: The halides, nitrate , and sulfate . For similar reasons, anhydrous aluminium salts cannot be made by heating their "hydrates": hydrated aluminium chloride is in fact not AlCl 3 ·6H 2 O but [Al(H 2 O) 6 ]Cl 3 , and the Al–O bonds are so strong that heating is not sufficient to break them and form Al–Cl bonds instead: All four trihalides are well known. Unlike the structures of the three heavier trihalides, aluminium fluoride (AlF 3 ) features six-coordinate aluminium, which explains its involatility and insolubility as well as high heat of formation . Each aluminium atom
20587-432: The involvement of the French, Dutch and English, before declining in the 19th century. At least 12 million slaves were transported from Africa. The slave trade increased inter-tribal warfare and stunted population growth and economic development in the west African interior. Indigenous encounters with Europeans increased during the age of discovery . The Europeans were motivated by a range of factors including trade,
20760-450: The island after their boat's makeshift anchor failed during the night. They did not respond to warning calls from passing fishermen, and their boat drifted into the shallows near the island, where a group of Sentinelese tribals attacked it and killed the fishermen with axes. According to one report, the bodies were later put on bamboo stakes facing out to sea like scarecrows . Three days later, an Indian Coast Guard helicopter, dispatched for
20933-622: The island by a colonial officer was by Jeremiah Homfray in 1867. He recorded seeing naked islanders catching fish with bows and arrows, and was informed by the Great Andamanese that they were Jarawas. In 1880, in an effort to establish contact with the Sentinelese, the Royal Navy officer Maurice Vidal Portman , who was serving as a colonial administrator to the Andaman and Nicobar Islands , led an armed group of Europeans along with convict-orderlies and Andamanese trackers (whom they had already befriended) to North Sentinel Island. On their arrival,
21106-405: The island by a professional anthropologist. Through binoculars, the group saw several clusters of Sentinelese along the coastline who retreated into the forest as the team advanced. The team followed their footprints and after about 1 kilometre (0.62 mi), found a group of 18 lean-to huts made from grass and leaves that showed signs of recent occupation as evidenced by the still-burning fires at
21279-457: The islanders fled into the treeline. After several days of futile search, during which they found abandoned villages and paths, Portman's men captured six people: an elderly man, a woman and four children. The man and woman died of illness shortly after their arrival in Port Blair and the children began to fall ill as well. Portman hurriedly sent the children back to North Sentinel Island with
21452-458: The jungle to take the gifts but then attacked the party with arrows. Other gestures in response to contact parties, such as swaying of penises, have been noted. On some of his visits, Pandit brought some Onge to the island to try to communicate with the Sentinelese, but the attempts were usually futile and Pandit reported one instance of angering the Sentinelese. In 1977, the Rusley ran aground off
21625-461: The local environment and disrupted traditional agriculture and hunting practices. The indigenous populations of the Pacific had increasing contact with Europeans in the 18th century as British, French and Spanish expeditions explored the region. The natives of Tahiti had encounters with the expeditions of Wallis (1766), Bougainville (1768), Cook (1769) and many others before being colonized by
21798-433: The low-pressure polymerization of ethene and propene . There are also some heterocyclic and cluster organoaluminium compounds involving Al–N bonds. The industrially most important aluminium hydride is lithium aluminium hydride (LiAlH 4 ), which is used as a reducing agent in organic chemistry . It can be produced from lithium hydride and aluminium trichloride . The simplest hydride, aluminium hydride or alane,
21971-529: The metal remained rare; its cost exceeded that of gold. The first industrial production of aluminium was established in 1856 by French chemist Henri Etienne Sainte-Claire Deville and companions. Deville had discovered that aluminium trichloride could be reduced by sodium, which was more convenient and less expensive than potassium, which Wöhler had used. Even then, aluminium was still not of great purity and produced aluminium differed in properties by sample. Because of its electricity-conducting capacity, aluminium
22144-603: The metal to be isolated from alum was alumium , which Davy suggested in an 1808 article on his electrochemical research, published in Philosophical Transactions of the Royal Society . It appeared that the name was created from the English word alum and the Latin suffix -ium ; but it was customary then to give elements names originating in Latin, so this name was not adopted universally. This name
22317-465: The metal with many uses at the time. During World War I , major governments demanded large shipments of aluminium for light strong airframes; during World War II , demand by major governments for aviation was even higher. By the mid-20th century, aluminium had become a part of everyday life and an essential component of housewares. In 1954, production of aluminium surpassed that of copper , historically second in production only to iron, making it
22490-434: The metal. Almost all metallic aluminium is produced from the ore bauxite (AlO x (OH) 3–2 x ). Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions. In 2017, most bauxite was mined in Australia, China, Guinea, and India. The history of aluminium has been shaped by usage of alum . The first written record of alum, made by Greek historian Herodotus , dates back to
22663-485: The monomer and dimer. These dimers, such as trimethylaluminium (Al 2 Me 6 ), usually feature tetrahedral Al centers formed by dimerization with some alkyl group bridging between both aluminium atoms. They are hard acids and react readily with ligands, forming adducts. In industry, they are mostly used in alkene insertion reactions, as discovered by Karl Ziegler , most importantly in "growth reactions" that form long-chain unbranched primary alkenes and alcohols, and in
22836-506: The most produced non-ferrous metal . During the mid-20th century, aluminium emerged as a civil engineering material, with building applications in both basic construction and interior finish work, and increasingly being used in military engineering, for both airplanes and land armor vehicle engines. Earth's first artificial satellite , launched in 1957, consisted of two separate aluminium semi-spheres joined and all subsequent space vehicles have used aluminium to some extent. The aluminium can
23009-551: The national community and whose status is regulated wholly or partially by their own customs or traditions or by special laws or regulations." The convention states that self-identification as indigenous or tribal is a fundamental criterion for determining the groups to which the convention applies. The UN Declaration on the Rights of Indigenous Peoples does not define Indigenous peoples but affirms their right to self-determination including determining their own identity. The Inter-American Commission on Human Rights does not provide
23182-473: The natural resources by the numerous mercenary outlaws who took refuge in those regions, and probably contribute to the Sentineleses' extinction. Accordingly, in 1970, an official surveying party landed at an isolated spot on the island and erected a stone tablet, atop a disused native hearth, that declared the island part of India. In early 1974, a National Geographic film crew went to the island with
23355-417: The necessary permits required to visit the island. On 15 November, Chau paid local fishermen to take him to a point 500–700 metres (1,600–2,300 feet) from the island's shore, then continued to the island in a canoe. As he approached, he attempted to communicate with the islanders and offer gifts, but retreated after facing hostile responses. On another visit, Chau recorded that the islanders reacted to him with
23528-614: The next decade, the -um spelling dominated American usage. In 1925, the American Chemical Society adopted this spelling. The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990. In 1993, they recognized aluminum as an acceptable variant; the most recent 2005 edition of the IUPAC nomenclature of inorganic chemistry also acknowledges this spelling. IUPAC official publications use
23701-462: The north coast of North Sentinel Island. On 2 August 1981, the MV Primrose , carrying a bulk cargo of chicken feed from Bangladesh to Australia, ran aground in rough seas just off North Sentinel Island, stranding a small crew. After a few days, the captain dispatched a distress call asking for a drop of firearms and reported boats being prepared by more than 50 armed islanders intending to board
23874-407: The oxidation state 3+. The coordination number of such compounds varies, but generally Al is either six- or four-coordinate. Almost all compounds of aluminium(III) are colorless. In aqueous solution, Al exists as the hexaaqua cation [Al(H 2 O) 6 ] , which has an approximate K a of 10 . Such solutions are acidic as this cation can act as a proton donor and progressively hydrolyze until
24047-409: The party. Once a woman pushed the arrow down, the man buried his weapons in the sand and the Sentinelese approached quite close to the dinghies for the first time. The Director of Tribal Welfare distributed five bags of coconuts hand-to-hand. Pandya comments: Those present in the defining moment of physical contact now wished to extract professional mileage from the fact of being actually 'touched' by
24220-460: The patents he filed between 1886 and 1903. It is unknown whether this spelling was introduced by mistake or intentionally, but Hall preferred aluminum since its introduction because it resembled platinum , the name of a prestigious metal. By 1890, both spellings had been common in the United States, the -ium spelling being slightly more common; by 1895, the situation had reversed; by 1900, aluminum had become twice as common as aluminium ; in
24393-577: The population has been variously estimated to be as low as 15 or as high as 500. Most estimates lie between 50 and 200. The 1971 census estimated the population at around 82, and the 1981 census at 100. A 1986 expedition recorded the highest count, 98. In 2001, the census of India officially recorded 21 men and 18 women. This survey was conducted from a distance and may not have been accurate. 2004 post- tsunami expeditions recorded counts of 32 and 13 individuals in 2004 and 2005, respectively. The 2011 census of India recorded 12 males and three females. During
24566-416: The principles of the discovery doctrine: The United States ... [and] its civilized inhabitants now hold this country. They hold, and assert in themselves, the title by which it was acquired. They maintain, as all others have maintained, that discovery gave an exclusive right to extinguish the Indian title of occupancy, either by purchase or by conquest; and gave also a right to such a degree of sovereignty, as
24739-468: The purpose of establishing friendly contact. Many of these got a friendly reception, with hoards of gifts left for them, but some ended in violent encounters, which were mostly suppressed. Some of the expeditions (1987, 1992, et al.) were entirely documented on film. Sometimes the Sentinelese waved and sometimes they turned their backs and assumed a "defecating" posture, which Pandit took as a sign of their not being welcome. On some occasions, they rushed out of
24912-399: The purpose, found the buried bodies. When the helicopter tried to retrieve them, the Sentinelese attacked it with arrows, and according to some sources with spears, and the mission was soon abandoned. There were contrasting views in the local community as to whether the Sentinelese ought to be prosecuted for the murder. Pandya hypothesizes that the aggressive response might have been caused by
25085-423: The respective hydrogen chalcogenide . As aluminium is a small atom relative to these chalcogens, these have four-coordinate tetrahedral aluminium with various polymorphs having structures related to wurtzite , with two-thirds of the possible metal sites occupied either in an orderly (α) or random (β) fashion; the sulfide also has a γ form related to γ-alumina, and an unusual high-temperature hexagonal form where half
25258-450: The sand, including a miniature plastic car, some coconuts, a live pig, a doll and aluminium cookware. The Sentinelese followed up by launching another volley of arrows, one of which struck the documentary director in his thigh. The man who wounded the director withdrew to the shade of a tree and laughed proudly while others speared and buried the pig and the doll. They left afterward, taking the coconuts and cookware. This expedition also led to
25431-485: The scale of the economies. However, the need to exploit lower-grade poorer quality deposits and the use of fast increasing input costs (above all, energy) increased the net cost of aluminium; the real price began to grow in the 1970s with the rise of energy cost. Production moved from the industrialized countries to countries where production was cheaper. Production costs in the late 20th century changed because of advances in technology, lower energy prices, exchange rates of
25604-518: The ship. Strong waves prevented the Sentinelese canoes from reaching the ship and deflected their arrows. The crew of 31 men were keeping a twenty-four-hour guard with axes, pipes, and flare guns. Nearly a week later, the crew was evacuated by a civilian helicopter contracted to the Oil and Natural Gas Corporation (ONGC) with support from Indian naval forces. The Sentinelese scoured the abandoned shipwrecks to salvage iron for their weaponry. M. A. Mohammad,
25777-695: The sources available to him then, concluding that Pelasgians were Greek. In European late antiquity, many Berbers , Copts and Nubians of north Africa converted to various forms of Christianity under Roman rule, although elements of traditional religious beliefs were retained. Following the Arab invasions of North Africa in the 7th century, many Berbers were enslaved or recruited into the army. The majority of Berbers, however, remained nomadic pastoralists who also engaged in trade as far as sub-Saharan Africa. Coptic Egyptians remained in possession of their lands and many preserved their language and Christian religion. By
25950-408: The structure of BCl 3 . Aluminium tribromide and aluminium triiodide form Al 2 X 6 dimers in all three phases and hence do not show such significant changes of properties upon phase change. These materials are prepared by treating aluminium with the halogen. The aluminium trihalides form many addition compounds or complexes; their Lewis acidic nature makes them useful as catalysts for
26123-415: The sudden withdrawal of those gift-carrying expeditions, which was not influenced or informed by any acts of the Sentinelese. He also notes that while the images of the hostile Sentinelese the helicopter sorties captured were heavily propagated in the media, the images of them burying the dead were never released. This selective display effectively negated the friendly images that circulated in the aftermath of
26296-809: The term Indigenous peoples or have denied that Indigenous peoples exist in their territory, and have classified minorities who identify as Indigenous in other ways, such as 'hill tribes' in Thailand, 'scheduled tribes' in India, 'national minorities' in China, 'cultural minorities' in the Philippines, 'isolated and alien peoples' in Indonesia, and various other terms. Greek sources of the Classical period acknowledge Indigenous people whom they referred to as " Pelasgians ". Ancient writers saw these people either as
26469-483: The term is necessary, given that a single definition will inevitably be either over- or under-inclusive, making sense in some societies but not in others." However, a number of UN agencies have provided statements of coverage for particular international agreements concerning Indigenous peoples or "working definitions" for particular reports. The International Labour Organization's (ILO) Indigenous and Tribal Peoples Convention, 1989 (ILO Convention No. 169), states that
26642-460: The third day, they were subject to a sudden assault by a group of naked, short-haired, red-painted islanders with arrows that were probably iron-tipped. The captain, who fled in the ship's boat, was found days later by a brig and the Royal Navy sent a rescue party to the island. Upon arrival, the party discovered that the survivors had managed to repel the attackers with sticks and stones and that they had not reappeared. The first recorded visit to
26815-636: The total world population. This includes at least 5,000 distinct peoples. As there is no universally accepted definition of Indigenous Peoples, their classification as such varies between countries and organizations. In the Americas, Australia and New Zealand, Indigenous status is often applied unproblematically to groups descended from the peoples who lived there prior to European settlement. However, In Asia and Africa, Indigenous status has sometimes been rejected by certain peoples, denied by governments or applied to peoples who may not be considered "Indigenous" in other contexts. The concept of indigenous peoples
26988-449: The tribe and attempted to establish friendly contact, they did not recognize him and responded aggressively by shooting arrows at the group. The man refused to remain on the island. Portman cast doubt on the exact timespan the Sentinelese spent with the Onge, and believed that he had probably been raised by the Onge since childhood. Temple concluded the Sentinelese were "a tribe which slays every stranger, however inoffensive, on sight, whether
27161-536: The two therefore look similar. Aluminium is also good at reflecting solar radiation , although prolonged exposure to sunlight in air adds wear to the surface of the metal; this may be prevented if aluminium is anodized , which adds a protective layer of oxide on the surface. The density of aluminium is 2.70 g/cm , about 1/3 that of steel, much lower than other commonly encountered metals, making aluminium parts easily identifiable through their lightness. Aluminium's low density compared to most other metals arises from
27334-613: The value of metal, having scavenged it to create tools and weapons, and accepted aluminum cookware left by the National Geographic Society in 1974. There is no evidence of them having knowledge of metallurgy outside of cold forging to make tools such as arrow heads, though the Andamanese scholar Vishvajit Pandya notes that Onge narratives often recall voyages by their ancestors to North Sentinel to procure metal. Canoes are used for lagoon-fishing, but long poles rather than paddles or oars propel them. They seldom use
27507-739: The world. Most Indigenous peoples are in a minority in the state or traditional territory they inhabit and have experienced domination by other groups, especially non-Indigenous peoples. Although many Indigenous peoples have experienced colonization by settlers from European nations, Indigenous identity is not determined by Western colonization. The rights of Indigenous peoples are outlined in national legislation, treaties and international law. The 1989 International Labour Organization (ILO) Convention on Indigenous and Tribal Peoples protects Indigenous peoples from discrimination and specifies their rights to development, customary laws, lands, territories and resources, employment, education and health. In 2007,
27680-421: Was a crucial strategic resource for aviation . In 1954, aluminium became the most produced non-ferrous metal , surpassing copper . In the 21st century, most aluminium was consumed in transportation, engineering, construction, and packaging in the United States, Western Europe, and Japan. Despite its prevalence in the environment, no living organism is known to metabolize aluminium salts , but this aluminium
27853-461: Was a salt of an earth of alum. In 1595, German doctor and chemist Andreas Libavius experimentally confirmed this. In 1722, German chemist Friedrich Hoffmann announced his belief that the base of alum was a distinct earth. In 1754, German chemist Andreas Sigismund Marggraf synthesized alumina by boiling clay in sulfuric acid and subsequently adding potash . Attempts to produce aluminium date back to 1760. The first successful attempt, however,
28026-543: Was also concerned about the possibility of harm to the Sentinelese by an influx of outsiders, a result of them projecting a relatively friendly image. Photos of the 1991 expedition were removed from public display and use of them was restricted by the government. The next expedition was in April ;2003, when a canoe built by the Onges was given to the visitors. Further expeditions (some aerial) in 2004 and 2005 evaluated
28199-424: Was borrowed from French, which in turn derived it from alumen , the classical Latin name for alum , the mineral from which it was collected. The Latin word alumen stems from the Proto-Indo-European root *alu- meaning "bitter" or "beer". British chemist Humphry Davy , who performed a number of experiments aimed to isolate the metal, is credited as the person who named the element. The first name proposed for
28372-514: Was chief commissioner of the Andaman and Nicobar Islands from 1895 to 1904, reported that he had toured North Sentinel island to capture fugitives, but upon landing discovered that they had been killed by the inhabitants, who retreated in haste upon seeing his party approach. Temple also recorded a case where a Sentinelese apparently drifted off to the Onge and fraternized with them over the course of two years. When Temple and Portman accompanied him to
28545-422: Was completed in 1824 by Danish physicist and chemist Hans Christian Ørsted . He reacted anhydrous aluminium chloride with potassium amalgam , yielding a lump of metal looking similar to tin. He presented his results and demonstrated a sample of the new metal in 1825. In 1827, German chemist Friedrich Wöhler repeated Ørsted's experiments but did not identify any aluminium. (The reason for this inconsistency
28718-443: Was criticized by contemporary chemists from France, Germany, and Sweden, who insisted the metal should be named for the oxide, alumina, from which it would be isolated. The English name alum does not come directly from Latin, whereas alumine / alumina obviously comes from the Latin word alumen (upon declension , alumen changes to alumin- ). One example was Essai sur la Nomenclature chimique (July 1811), written in French by
28891-571: Was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and the mass production of aluminium led to its extensive use in industry and everyday life. In the First and Second World Wars, aluminium
29064-418: Was invented in 1956 and employed as a storage for drinks in 1958. Throughout the 20th century, the production of aluminium rose rapidly: while the world production of aluminium in 1900 was 6,800 metric tons, the annual production first exceeded 100,000 metric tons in 1916; 1,000,000 tons in 1941; 10,000,000 tons in 1971. In the 1970s, the increased demand for aluminium made it an exchange commodity; it entered
29237-589: Was motivated by a quest for gold and crusading against Islam. Portugal's first attempt at colonization in what is now Senegal ended in failure. In the 1470s, the Portuguese established a fortified trading post on the West coast of Africa, south of the Akan goldfields. The Portuguese engaged in extensive trade of goods for gold and, in later years, slaves for their sugar plantations in the islands off West Africa and in
29410-433: Was only discovered in 1921.) He conducted a similar experiment in the same year by mixing anhydrous aluminium chloride with potassium and produced a powder of aluminium. In 1845, he was able to produce small pieces of the metal and described some physical properties of this metal. For many years thereafter, Wöhler was credited as the discoverer of aluminium. As Wöhler's method could not yield great quantities of aluminium,
29583-412: Was used as a way of linking the experiences, issues, and struggles of groups of colonized people across international borders. At this time 'indigenous people(s)' also began to be used to describe a legal category in Indigenous law created in international and national legislation. The use of the plural 'peoples' recognizes the cultural differences between various Indigenous peoples. The first meeting of
29756-580: Was used as the cap of the Washington Monument , completed in 1885. The tallest building in the world at the time, the non-corroding metal cap was intended to serve as a lightning rod peak. The first industrial large-scale production method was independently developed in 1886 by French engineer Paul Héroult and American engineer Charles Martin Hall ; it is now known as the Hall–Héroult process . The Hall–Héroult process converts alumina into metal. Austrian chemist Carl Joseph Bayer discovered
29929-509: Was visited by numerous European and North American whaling, sealing, and trading ships. From the early 19th century, Christian missionaries began to settle New Zealand, eventually converting most of the Māori population. The Māori population declined to around 40% of its pre-contact level during the 19th century; introduced diseases were the major factor. New Zealand became a British Crown colony in 1841. The Aboriginal inhabitants of Australia, after brief encounters with European explorers in
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