87-518: The Atomium ( / ə ˈ t oʊ m i ə m / ə- TOH -mee-əm , French: [atɔmjɔm] , Dutch: [aːˈtoːmijəm] ) is a landmark modernist building in Brussels , Belgium, originally constructed as the centrepiece of the 1958 Brussels World's Fair ( Expo 58 ). Designed by the engineer André Waterkeyn and the architects André and Jean Polak as a tribute to scientific progress, as well as to symbolise Belgian engineering skills at
174-434: A body-centered cubic (bcc) crystal structure . As it cools further to 1394 °C, it changes to its γ-iron allotrope, a face-centered cubic (fcc) crystal structure, or austenite . At 912 °C and below, the crystal structure again becomes the bcc α-iron allotrope. The physical properties of iron at very high pressures and temperatures have also been studied extensively, because of their relevance to theories about
261-430: A nuclear spin (− 1 ⁄ 2 ). The nuclide Fe theoretically can undergo double electron capture to Cr, but the process has never been observed and only a lower limit on the half-life of 4.4×10 years has been established. Fe is an extinct radionuclide of long half-life (2.6 million years). It is not found on Earth, but its ultimate decay product is its granddaughter, the stable nuclide Ni . Much of
348-499: A supernova for their formation, involving rapid neutron capture by starting Fe nuclei. In the far future of the universe, assuming that proton decay does not occur, cold fusion occurring via quantum tunnelling would cause the light nuclei in ordinary matter to fuse into Fe nuclei. Fission and alpha-particle emission would then make heavy nuclei decay into iron, converting all stellar-mass objects to cold spheres of pure iron. Iron's abundance in rocky planets like Earth
435-490: A "cultural guerrilla strike" by asking people to send in their old photographs of the Atomium and requested 100 photoshoppers to paint over the balls. SABAM responded that they would make an exception for 2008 and that people could publish private photographs for one year only on condition they were for non-commercial purposes. Anno Expo later announced they had censored part of their own report due to "complications" and referred to
522-454: A distorted sodium chloride structure. The binary ferrous and ferric halides are well-known. The ferrous halides typically arise from treating iron metal with the corresponding hydrohalic acid to give the corresponding hydrated salts. Iron reacts with fluorine, chlorine, and bromine to give the corresponding ferric halides, ferric chloride being the most common. Ferric iodide is an exception, being thermodynamically unstable due to
609-583: A familiar or unfamiliar environment. Landmarks are often used in verbal route instructions ("Turn left at the big church and then right over the bridge.") Landmarks are usually classified as either natural landmarks or human-made landmarks, both are originally used to support navigation on finding directions. A variant is a seamark or daymark , a structure usually built intentionally to aid sailors navigating featureless coasts. Natural landmarks can be characteristic features, such as mountains or plateaus . Examples of natural landmarks are Mount Everest in
696-418: A landmark character. Iron Iron is a chemical element ; it has the symbol Fe (from Latin ferrum 'iron') and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table . It is, by mass, the most common element on Earth , forming much of Earth's outer and inner core . It is the fourth most abundant element in
783-548: A landmark to help sailors to navigate around the southern tip of Africa during the Age of Exploration . Artificial structures are also sometimes built to assist sailors in navigation. The Lighthouse of Alexandria and the Colossus of Rhodes are ancient structures built to lead ships to the port. In modern usage, a landmark includes anything that is easily recognizable, such as a monument , building, or other structure. In American English it
870-553: A macroscopic piece of iron will have a nearly zero overall magnetic field. Application of an external magnetic field causes the domains that are magnetized in the same general direction to grow at the expense of adjacent ones that point in other directions, reinforcing the external field. This effect is exploited in devices that need to channel magnetic fields to fulfill design function, such as electrical transformers , magnetic recording heads, and electric motors . Impurities, lattice defects , or grain and particle boundaries can "pin"
957-511: A major element of Brussels' landscape. Its destruction was therefore postponed year after year, until the city's authorities decided to keep it. However, for thirty years, little maintenance work was done. Still, the building continued serving as the backdrop for major events and competitions. In 1960, the 47th Tour de France passed in front of it on its inaugural stages. From 1960 to 1962, the Brussels Motor Grand Prix automobile race
SECTION 10
#17328386119831044-445: A meeting they had with SABAM. Mechelen's mayor, Bart Somers , called the Atomium copyright rules absurd. From the Atomium's website, the current copyright restrictions exempt private individuals under the following conditions: This is the case where photographs are taken by private individuals and shown on private websites for no commercial purpose (the current trend for photo albums). In accordance with legislation, usage rights for
1131-477: A mirror-like silvery-gray. Iron reacts readily with oxygen and water to produce brown-to-black hydrated iron oxides , commonly known as rust . Unlike the oxides of some other metals that form passivating layers, rust occupies more volume than the metal and thus flakes off, exposing more fresh surfaces for corrosion. Chemically, the most common oxidation states of iron are iron(II) and iron(III) . Iron shares many properties of other transition metals, including
1218-475: A mixture of O 2 /Ar. Iron(IV) is a common intermediate in many biochemical oxidation reactions. Numerous organoiron compounds contain formal oxidation states of +1, 0, −1, or even −2. The oxidation states and other bonding properties are often assessed using the technique of Mössbauer spectroscopy . Many mixed valence compounds contain both iron(II) and iron(III) centers, such as magnetite and Prussian blue ( Fe 4 (Fe[CN] 6 ) 3 ). The latter
1305-471: A result, mercury is traded in standardized 76 pound flasks (34 kg) made of iron. Iron is by far the most reactive element in its group; it is pyrophoric when finely divided and dissolves easily in dilute acids, giving Fe . However, it does not react with concentrated nitric acid and other oxidizing acids due to the formation of an impervious oxide layer, which can nevertheless react with hydrochloric acid . High-purity iron, called electrolytic iron ,
1392-449: A structure would have toppled in an 80 km/h (50 mph) wind, whilst up to 140 km/h (90 mph) winds have been recorded in Belgium. Support columns were thus added under the three spheres in question to achieve enough resistance against overturning. The Atomium, designed to last six months, was not destined to survive the 1958 World's Fair, but its popularity and success made it
1479-455: A type of rock consisting of repeated thin layers of iron oxides alternating with bands of iron-poor shale and chert . The banded iron formations were laid down in the time between 3,700 million years ago and 1,800 million years ago . Materials containing finely ground iron(III) oxides or oxide-hydroxides, such as ochre , have been used as yellow, red, and brown pigments since pre-historical times. They contribute as well to
1566-435: A very large coordination and organometallic chemistry : indeed, it was the discovery of an iron compound, ferrocene , that revolutionalized the latter field in the 1950s. Iron is sometimes considered as a prototype for the entire block of transition metals, due to its abundance and the immense role it has played in the technological progress of humanity. Its 26 electrons are arranged in the configuration [Ar]3d 4s , of which
1653-433: Is a recognizable natural or artificial feature used for navigation , a feature that stands out from its near environment and is often visible from long distances. In modern day use, the term can also be applied to smaller structures or features, that have become local or national symbols . In old English the word landmearc (from land + mearc (mark)) was used to describe a boundary marker , an "object set up to mark
1740-630: Is also rarely found in basalts that have formed from magmas that have come into contact with carbon-rich sedimentary rocks, which have reduced the oxygen fugacity sufficiently for iron to crystallize. This is known as telluric iron and is described from a few localities, such as Disko Island in West Greenland, Yakutia in Russia and Bühl in Germany. Ferropericlase (Mg,Fe)O , a solid solution of periclase (MgO) and wüstite (FeO), makes up about 20% of
1827-569: Is considered the transition from the Bronze Age to the Iron Age . In the modern world , iron alloys, such as steel , stainless steel , cast iron and special steels , are by far the most common industrial metals, due to their mechanical properties and low cost. The iron and steel industry is thus very important economically, and iron is the cheapest metal, with a price of a few dollars per kilogram or pound. Pristine and smooth pure iron surfaces are
SECTION 20
#17328386119831914-407: Is considered to be resistant to rust, due to its oxide layer. Iron forms various oxide and hydroxide compounds ; the most common are iron(II,III) oxide (Fe 3 O 4 ), and iron(III) oxide (Fe 2 O 3 ). Iron(II) oxide also exists, though it is unstable at room temperature. Despite their names, they are actually all non-stoichiometric compounds whose compositions may vary. These oxides are
2001-495: Is due to its abundant production during the runaway fusion and explosion of type Ia supernovae , which scatters the iron into space. Metallic or native iron is rarely found on the surface of the Earth because it tends to oxidize. However, both the Earth's inner and outer core , which together account for 35% of the mass of the whole Earth, are believed to consist largely of an iron alloy, possibly with nickel . Electric currents in
2088-474: Is experimentally well defined for pressures less than 50 GPa. For greater pressures, published data (as of 2007) still varies by tens of gigapascals and over a thousand kelvin. Below its Curie point of 770 °C (1,420 °F; 1,040 K), α-iron changes from paramagnetic to ferromagnetic : the spins of the two unpaired electrons in each atom generally align with the spins of its neighbors, creating an overall magnetic field . This happens because
2175-490: Is in Earth's crust only amounts to about 5% of the overall mass of the crust and is thus only the fourth most abundant element in that layer (after oxygen , silicon , and aluminium ). Most of the iron in the crust is combined with various other elements to form many iron minerals . An important class is the iron oxide minerals such as hematite (Fe 2 O 3 ), magnetite (Fe 3 O 4 ), and siderite (FeCO 3 ), which are
2262-401: Is not like that of Mn with its weak, spin-forbidden d–d bands, because Fe has higher positive charge and is more polarizing, lowering the energy of its ligand-to-metal charge transfer absorptions. Thus, all the above complexes are rather strongly colored, with the single exception of the hexaquo ion – and even that has a spectrum dominated by charge transfer in the near ultraviolet region. On
2349-407: Is possible, but nonetheless the sequence does effectively end at Ni because conditions in stellar interiors cause the competition between photodisintegration and the alpha process to favor photodisintegration around Ni. This Ni, which has a half-life of about 6 days, is created in quantity in these stars, but soon decays by two successive positron emissions within supernova decay products in
2436-548: Is somewhat different). Pieces of magnetite with natural permanent magnetization ( lodestones ) provided the earliest compasses for navigation. Particles of magnetite were extensively used in magnetic recording media such as core memories , magnetic tapes , floppies , and disks , until they were replaced by cobalt -based materials. Iron has four stable isotopes : Fe (5.845% of natural iron), Fe (91.754%), Fe (2.119%) and Fe (0.282%). Twenty-four artificial isotopes have also been created. Of these stable isotopes, only Fe has
2523-442: Is such a strong oxidizing agent that it oxidizes ammonia to nitrogen (N 2 ) and water to oxygen: The pale-violet hex aquo complex [Fe(H 2 O) 6 ] is an acid such that above pH 0 it is fully hydrolyzed: As pH rises above 0 the above yellow hydrolyzed species form and as it rises above 2–3, reddish-brown hydrous iron(III) oxide precipitates out of solution. Although Fe has a d configuration, its absorption spectrum
2610-502: Is supposed to have an orthorhombic or a double hcp structure. (Confusingly, the term "β-iron" is sometimes also used to refer to α-iron above its Curie point, when it changes from being ferromagnetic to paramagnetic, even though its crystal structure has not changed. ) The inner core of the Earth is generally presumed to consist of an iron- nickel alloy with ε (or β) structure. The melting and boiling points of iron, along with its enthalpy of atomization , are lower than those of
2697-550: Is the main term used to designate places that might be of interest to tourists, due to notable physical features or historical significance. Landmarks in the British English sense are often used for casual navigation , such as giving directions. This is done in American English as well. In urban studies as well as in geography , a landmark is furthermore defined as an external point of reference that helps orientation in
Atomium - Misplaced Pages Continue
2784-466: Is the most popular tourist attraction in Brussels, and acts as an international symbol of both the city and country. In addition to its heritage value, it is also a cultural place and an art centre. Over half of the building is dedicated to exhibitions with themes about Belgium and digital arts . Of the six spheres accessible to the public: the bottom sphere is reserved for permanent exhibitions dedicated to
2871-451: Is used as the traditional "blue" in blueprints . Iron is the first of the transition metals that cannot reach its group oxidation state of +8, although its heavier congeners ruthenium and osmium can, with ruthenium having more difficulty than osmium. Ruthenium exhibits an aqueous cationic chemistry in its low oxidation states similar to that of iron, but osmium does not, favoring high oxidation states in which it forms anionic complexes. In
2958-425: Is used both in the masculine and in the feminine, even if the monument's official team prefers the feminine. In Dutch, het Atomium (pronounced [aːˈtoːmijəm] ) is neuter. In English, it is usually referred to with the definite article 'the' in front: the Atomium . The Atomium was built as the main pavilion and icon of the 1958 Brussels World's Fair ( Expo 58 ). In the 1950s, faith in scientific progress
3045-437: Is used in chemical actinometry and along with its sodium salt undergoes photoreduction applied in old-style photographic processes. The dihydrate of iron(II) oxalate has a polymeric structure with co-planar oxalate ions bridging between iron centres with the water of crystallisation located forming the caps of each octahedron, as illustrated below. Iron(III) complexes are quite similar to those of chromium (III) with
3132-492: The Brussels Metro . The name Atomium (pronounced / ə ˈ t oʊ m iː ə m / ə- TOH -mee-əm ) is a portmanteau combining the words atom and aluminium , the metal with which the spheres were initially covered. The Brussels-Capital Region is bilingual ; hence, both the monument's French and Dutch names— l'Atomium and het Atomium —are official. In French, l'Atomium (pronounced [atɔmjɔm] )
3219-549: The Earth's crust , being mainly deposited by meteorites in its metallic state. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching 1,500 °C (2,730 °F), about 500 °C (932 °F) higher than that required to smelt copper . Humans started to master that process in Eurasia during the 2nd millennium BC and the use of iron tools and weapons began to displace copper alloys – in some regions, only around 1200 BC. That event
3306-1354: The Eiffel Tower in Paris , Saint Basil's Cathedral in Moscow , the Lotte World Tower in Seoul , the Colosseum in Rome , Big Ben in London , the Tsūtenkaku in Osaka , the Forbidden City in Beijing , the Great Pyramid in Giza , Christ the Redeemer in Rio de Janeiro , Statue of Unity in Narmada , Bratislava Castle in Bratislava , Helsinki Cathedral in Helsinki ,
3393-824: The Himalayas , Table Mountain in South Africa, Mount Ararat in Turkey, Uluru in Australia, Mount Fuji in Japan and the Grand Canyon in the United States. Trees might also serve as local landmarks, such as jubilee oaks or conifers . Some landmark trees may be named, such as Queen's Oak , Hanging Oak and Centennial Tree . Bases of fallen trees, known in this context as rootstocks , are used as navigational aids on high-resolution maps and in
3480-1406: The Space Needle in Seattle , the Sydney Opera House in Sydney , the Brandenburg Gate in Berlin , the Château Frontenac in Quebec (city) , Place Stanislas in Nancy , the CN Tower in Toronto , the Palace of Culture and Science in Warsaw , the Atomium in Brussels , Gateway Arch in St Louis , and the Moai in Easter Island . Church spires and mosque minarets are often very tall and visible from many miles around and thus often serve as built landmarks. Also town hall towers and belfries often have
3567-429: The post-war ideal to peacefully apply atomic research and other advancements in technology in order to improve lives and serve the betterment of mankind. The Atomium's nine 18-metre-diameter (59 ft) stainless steel clad spheres depict nine iron atoms in the shape of the body-centred cubic unit cell that could for example represent α-iron ( ferrite ) crystal , magnified 165 billion times. The construction of
Atomium - Misplaced Pages Continue
3654-432: The supernova remnant gas cloud, first to radioactive Co, and then to stable Fe. As such, iron is the most abundant element in the core of red giants , and is the most abundant metal in iron meteorites and in the dense metal cores of planets such as Earth . It is also very common in the universe, relative to other stable metals of approximately the same atomic weight . Iron is the sixth most abundant element in
3741-488: The trans - chlorohydridobis(bis-1,2-(diphenylphosphino)ethane)iron(II) complex is used as a starting material for compounds with the Fe( dppe ) 2 moiety . The ferrioxalate ion with three oxalate ligands displays helical chirality with its two non-superposable geometries labelled Λ (lambda) for the left-handed screw axis and Δ (delta) for the right-handed screw axis, in line with IUPAC conventions. Potassium ferrioxalate
3828-466: The universe , and the most common refractory element. Although a further tiny energy gain could be extracted by synthesizing Ni , which has a marginally higher binding energy than Fe, conditions in stars are unsuitable for this process. Element production in supernovas greatly favor iron over nickel, and in any case, Fe still has a lower mass per nucleon than Ni due to its higher fraction of lighter protons. Hence, elements heavier than iron require
3915-458: The 1950s, Expo 58 and the building's construction; the second sphere hosts temporary exhibitions; the third and central spheres have flexible spaces that can be rented for events, such as film showings, concerts, parties or conferences; the top sphere, in addition to the panorama, holds a restaurant; and the sixth sphere is the kids' sphere, intended for the organisation of workshops of urban pedagogy, allowing children from six to twelve years to spend
4002-570: The 3d and 4s electrons are relatively close in energy, and thus a number of electrons can be ionized. Iron forms compounds mainly in the oxidation states +2 ( iron(II) , "ferrous") and +3 ( iron(III) , "ferric"). Iron also occurs in higher oxidation states , e.g., the purple potassium ferrate (K 2 FeO 4 ), which contains iron in its +6 oxidation state. The anion [FeO 4 ] with iron in its +7 oxidation state, along with an iron(V)-peroxo isomer, has been detected by infrared spectroscopy at 4 K after cocondensation of laser-ablated Fe atoms with
4089-650: The Atomium was a technical feat. In January 1955, a first project was presented by the engineer André Waterkeyn , director of the economic department of Fabrimétal [ fr ] , the Federation of Companies in the Metal Fabricating Industry (now known as Agoria ). The architects André and Jean Polak were responsible for the architectural transposition of the concept, drawing up numerous sketches to do so. The company received assistance from consulting engineers Artémy S. Joukoff and André Beckers, assisted by
4176-423: The Atomium, and that A.S.B.L. Atomium will sue any individual or group if they show the photographs to anyone. SABAM confirmed that permission is required. Ralf Ziegermann remarked on the complicated copyright instructions on the Atomium's website specific to "private pictures". The organisers of Belgian heritage, Anno Expo (planning the 50th anniversary celebrations of Expo 58), in the city of Mechelen announced
4263-589: The Earth's surface. Items made of cold-worked meteoritic iron have been found in various archaeological sites dating from a time when iron smelting had not yet been developed; and the Inuit in Greenland have been reported to use iron from the Cape York meteorite for tools and hunting weapons. About 1 in 20 meteorites consist of the unique iron-nickel minerals taenite (35–80% iron) and kamacite (90–95% iron). Native iron
4350-461: The boundaries of a kingdom, estate, etc.". Starting from around 1560, this understanding of "landmark" was replaced by a more general one. A landmark became a "conspicuous object in a landscape". A landmark literally meant a geographic feature used by explorers and others to find their way back or through an area. For example, the Table Mountain near Cape Town , South Africa was used as
4437-450: The brown deposits present in a sizeable number of streams. Due to its electronic structure, iron has a very large coordination and organometallic chemistry. Many coordination compounds of iron are known. A typical six-coordinate anion is hexachloroferrate(III), [FeCl 6 ] , found in the mixed salt tetrakis(methylammonium) hexachloroferrate(III) chloride . Complexes with multiple bidentate ligands have geometric isomers . For example,
SECTION 50
#17328386119834524-545: The building was issued to celebrate the renovation and reopening. Though the Atomium depicts an iron unit cell, the spheres were originally clad with aluminium. Following the 2004–2006 renovation, however, the aluminium was replaced with stainless steel, which is primarily iron. Likewise, while the subject of Atomium was chosen to depict the enthusiasm of the Atomic Age , iron is not and cannot be used as fuel in nuclear reactions . The Atomium, with over 600,000 visitors per year,
4611-683: The color of various rocks and clays , including entire geological formations like the Painted Hills in Oregon and the Buntsandstein ("colored sandstone", British Bunter ). Through Eisensandstein (a jurassic 'iron sandstone', e.g. from Donzdorf in Germany) and Bath stone in the UK, iron compounds are responsible for the yellowish color of many historical buildings and sculptures. The proverbial red color of
4698-703: The companies Jacques Delens and BESIX . The building is located on the Square de l'Atomium / Atomiumsquare , at the intersection of the Boulevard du Centenaire / Eeuwfeestlaan with the Avenue de l'Atomium / Atomiumlaan and the Avenue de Bouchout / Boechoutlaan , and opposite the Centenary Palace of the Brussels Exhibition Centre ( Brussels Expo ). It is served by Heysel/Heizel metro station on line 6 of
4785-464: The cores of the Earth and other planets. Above approximately 10 GPa and temperatures of a few hundred kelvin or less, α-iron changes into another hexagonal close-packed (hcp) structure, which is also known as ε-iron . The higher-temperature γ-phase also changes into ε-iron, but does so at higher pressure. Some controversial experimental evidence exists for a stable β phase at pressures above 50 GPa and temperatures of at least 1500 K. It
4872-606: The design office V. Daniel. The foundations were launched in March 1956 and the building, erected by the Jambes-Namur Construction Workshops, was completed less than a month before the inauguration of Expo 58, on 17 April 1958. Since opening, only six of the nine spheres are accessible to the public, the three of the central axis and the three lower outer ones, each with two main floors and a lower floor reserved for service. Tubes of 3 metres (10 ft) diameter connect
4959-401: The domains in the new positions, so that the effect persists even after the external field is removed – thus turning the iron object into a (permanent) magnet . Similar behavior is exhibited by some iron compounds, such as the ferrites including the mineral magnetite , a crystalline form of the mixed iron(II,III) oxide Fe 3 O 4 (although the atomic-scale mechanism, ferrimagnetism ,
5046-479: The earlier 3d elements from scandium to chromium , showing the lessened contribution of the 3d electrons to metallic bonding as they are attracted more and more into the inert core by the nucleus; however, they are higher than the values for the previous element manganese because that element has a half-filled 3d sub-shell and consequently its d-electrons are not easily delocalized. This same trend appears for ruthenium but not osmium . The melting point of iron
5133-406: The exception of iron(III)'s preference for O -donor instead of N -donor ligands. The latter tend to be rather more unstable than iron(II) complexes and often dissociate in water. Many Fe–O complexes show intense colors and are used as tests for phenols or enols . For example, in the ferric chloride test , used to determine the presence of phenols, iron(III) chloride reacts with a phenol to form
5220-474: The faded aluminium sheets on the spheres with stainless steel , as well as building a new reception pavilion with a boomerang -shaped roof. At the foot of the building, the roundabout was redeveloped into a concrete esplanade lined with continuous benches and a large step leading to the north-east. On 21 December 2005, the Atomium's new outdoor lighting was tested. The meridians of each sphere were covered with rectangular steel plates, in which LED lighting
5307-462: The global stock of iron in use in society is 2,200 kg per capita. More-developed countries differ in this respect from less-developed countries (7,000–14,000 vs 2,000 kg per capita). Ocean science demonstrated the role of the iron in the ancient seas in both marine biota and climate. Iron shows the characteristic chemical properties of the transition metals , namely the ability to form variable oxidation states differing by steps of one and
SECTION 60
#17328386119835394-533: The image of the Atomium would naturally extend to 1 January 2076, in other words, the seventieth anniversary of André Waterkeyn's death. In the summer of 2015, Belgian political party Open Vld , part of the then-ruling Michel I Government , proposed a bill to enable freedom of panorama in Belgium. The bill was enacted into law in June 2016, allowing pictures of the Atomium, and other public buildings under copyright, to be legally distributed. Landmark A landmark
5481-449: The liquid outer core are believed to be the origin of the Earth's magnetic field . The other terrestrial planets ( Mercury , Venus , and Mars ) as well as the Moon are believed to have a metallic core consisting mostly of iron. The M-type asteroids are also believed to be partly or mostly made of metallic iron alloy. The rare iron meteorites are the main form of natural metallic iron on
5568-446: The literature, this mineral phase of the lower mantle is also often called magnesiowüstite. Silicate perovskite may form up to 93% of the lower mantle, and the magnesium iron form, (Mg,Fe)SiO 3 , is considered to be the most abundant mineral in the Earth, making up 38% of its volume. While iron is the most abundant element on Earth, most of this iron is concentrated in the inner and outer cores. The fraction of iron that
5655-463: The longest in Europe. The biggest is 35 metres (100 ft) long. The three upper outer spheres lack vertical support and hence are not open to the public for safety reasons (to minimise foot traffic in the sphere). The original design called for no leg supports on the three lower outer spheres; the structure was simply to rest on the singular mid-bottom sphere. However, wind tunnel tests proved that such
5742-407: The major ores of iron . Many igneous rocks also contain the sulfide minerals pyrrhotite and pentlandite . During weathering , iron tends to leach from sulfide deposits as the sulfate and from silicate deposits as the bicarbonate. Both of these are oxidized in aqueous solution and precipitate in even mildly elevated pH as iron(III) oxide . Large deposits of iron are banded iron formations ,
5829-606: The meteorites Semarkona and Chervony Kut, a correlation between the concentration of Ni, the granddaughter of Fe, and the abundance of the stable iron isotopes provided evidence for the existence of Fe at the time of formation of the Solar System . Possibly the energy released by the decay of Fe, along with that released by Al , contributed to the remelting and differentiation of asteroids after their formation 4.6 billion years ago. The abundance of Ni present in extraterrestrial material may bring further insight into
5916-559: The necessary levels, human iron metabolism requires a minimum of iron in the diet. Iron is also the metal at the active site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants and animals. At least four allotropes of iron (differing atom arrangements in the solid) are known, conventionally denoted α , γ , δ , and ε . The first three forms are observed at ordinary pressures. As molten iron cools past its freezing point of 1538 °C, it crystallizes into its δ allotrope, which has
6003-498: The night there. SABAM , Belgium's society for collecting copyrights, has claimed worldwide intellectual property rights on all reproductions of the image via the United States Artists Rights Society (ARS). For example, SABAM issued a demand that a United States website remove all images of the Atomium from its pages. The website responded by replacing all such images with a warning not to take photographs of
6090-436: The orbitals of those two electrons (d z and d x − y ) do not point toward neighboring atoms in the lattice, and therefore are not involved in metallic bonding. In the absence of an external source of magnetic field, the atoms get spontaneously partitioned into magnetic domains , about 10 micrometers across, such that the atoms in each domain have parallel spins, but some domains have other orientations. Thus
6177-533: The origin and early history of the Solar System . The most abundant iron isotope Fe is of particular interest to nuclear scientists because it represents the most common endpoint of nucleosynthesis . Since Ni (14 alpha particles ) is easily produced from lighter nuclei in the alpha process in nuclear reactions in supernovae (see silicon burning process ), it is the endpoint of fusion chains inside extremely massive stars . Although adding more alpha particles
6264-549: The other group 8 elements , ruthenium and osmium . Iron forms compounds in a wide range of oxidation states , −4 to +7. Iron also forms many coordination compounds ; some of them, such as ferrocene , ferrioxalate , and Prussian blue have substantial industrial, medical, or research applications. The body of an adult human contains about 4 grams (0.005% body weight) of iron, mostly in hemoglobin and myoglobin . These two proteins play essential roles in oxygen transport by blood and oxygen storage in muscles . To maintain
6351-444: The other hand, the pale green iron(II) hexaquo ion [Fe(H 2 O) 6 ] does not undergo appreciable hydrolysis. Carbon dioxide is not evolved when carbonate anions are added, which instead results in white iron(II) carbonate being precipitated out. In excess carbon dioxide this forms the slightly soluble bicarbonate, which occurs commonly in groundwater, but it oxidises quickly in air to form iron(III) oxide that accounts for
6438-581: The oxidizing power of Fe and the high reducing power of I : Ferric iodide, a black solid, is not stable in ordinary conditions, but can be prepared through the reaction of iron pentacarbonyl with iodine and carbon monoxide in the presence of hexane and light at the temperature of −20 °C, with oxygen and water excluded. Complexes of ferric iodide with some soft bases are known to be stable compounds. The standard reduction potentials in acidic aqueous solution for some common iron ions are given below: The red-purple tetrahedral ferrate (VI) anion
6525-497: The past work on isotopic composition of iron has focused on the nucleosynthesis of Fe through studies of meteorites and ore formation. In the last decade, advances in mass spectrometry have allowed the detection and quantification of minute, naturally occurring variations in the ratios of the stable isotopes of iron. Much of this work is driven by the Earth and planetary science communities, although applications to biological and industrial systems are emerging. In phases of
6612-414: The principal ores for the production of iron (see bloomery and blast furnace). They are also used in the production of ferrites , useful magnetic storage media in computers, and pigments. The best known sulfide is iron pyrite (FeS 2 ), also known as fool's gold owing to its golden luster. It is not an iron(IV) compound, but is actually an iron(II) polysulfide containing Fe and S 2 ions in
6699-522: The public. The renovation cost €26 million. Brussels and the Atomium Association paid one-third of the costs, and the Belgian Government financed the other two thirds. To help finance the renovation, pieces of the old aluminium plates were sold to the public as souvenirs. One triangular piece about 2 metres (7 ft) long sold for €1,000. In March 2006, a 2 euro commemorative coin depicting
6786-437: The second half of the 3d transition series, vertical similarities down the groups compete with the horizontal similarities of iron with its neighbors cobalt and nickel in the periodic table, which are also ferromagnetic at room temperature and share similar chemistry. As such, iron, cobalt, and nickel are sometimes grouped together as the iron triad . Unlike many other metals, iron does not form amalgams with mercury . As
6873-446: The shape of a unit cell that could represent an iron crystal magnified 165 billion times. Steel tubes connecting the spheres enclose stairs, escalators and an elevator (in the central, vertical tube) to allow access to the six visitable spheres, which contain exhibit halls and other public spaces. The top sphere includes a restaurant with a panoramic view of Brussels. The building was completely renovated between 2004 and 2006 by
6960-518: The spheres along the twelve edges of the cube and all eight vertices to the centre. The central tube contains the fastest elevator in Europe of the time with a speed of 5 m/s (20 ft/s), installed by the Belgian branch of the Swiss firm Schlieren (subsequently taken over by Schindler ). It allows 22 people to reach the summit in 23 seconds. The escalators installed in the oblique tubes are also among
7047-698: The sport of orienteering . Because most woods have many fallen trees, generally only very large rootstocks are mapped. In the modern sense, landmarks are usually referred to as monuments or prominent distinctive buildings, used as the symbol of a certain area, city, or nation . Some examples are Tokyo Tower in Tokyo , the White House in Washington, D.C. , the Statue of Liberty and Empire State Building in New York City ,
7134-547: The surface of Mars is derived from an iron oxide-rich regolith . Significant amounts of iron occur in the iron sulfide mineral pyrite (FeS 2 ), but it is difficult to extract iron from it and it is therefore not exploited. In fact, iron is so common that production generally focuses only on ores with very high quantities of it. According to the International Resource Panel 's Metal Stocks in Society report ,
7221-611: The time, it is located on the Heysel/Heizel Plateau in Laeken (northern part of the City of Brussels ), where the exhibition took place. It is the city's most popular tourist attraction, and serves as a museum, an art centre and a cultural destination. The Atomium stands 102 metres (335 ft) tall, making it one of the tallest structures in Belgium . Its nine 18-metre-diameter (59 ft) stainless steel clad spheres are connected in
7308-455: The volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite (Mg,Fe)SiO 3 ; it also is the major host for iron in the lower mantle. At the bottom of the transition zone of the mantle, the reaction γ- (Mg,Fe) 2 [SiO 4 ] ↔ (Mg,Fe)[SiO 3 ] + (Mg,Fe)O transforms γ-olivine into a mixture of silicate perovskite and ferropericlase and vice versa. In
7395-458: Was great, and a structure depicting atoms was chosen to highlight humanity's advance in science, including nuclear physics , which Belgium itself was an avid practitioner ever since the Belgian Congo 's uranium became the dominant source of material used for nuclear fission , including that used for the world's first nuclear weapons . With the Atomium, Belgium wanted to highlight and promote
7482-508: Was integrated. The LED application illuminates the bulbs at night. The lights can also flash simultaneously or in turns at each meridian, symbolising the range of an electron around its core. In addition, the German industrial designer Ingo Maurer created lighting objects and installations for the interior of the building. On 14 February 2006, the Atomium was officially reopened by then- Prince Philippe , and on 18 February 2006, it opened again to
7569-457: Was organised not far from it. By the turn of the millennium , the state of the building had deteriorated and a comprehensive renovation was sorely needed. Renovation of the Atomium, carried by Belgian construction companies Jacques Delens and BESIX , began in March 2004; it was closed to the public in October of that year, and remained closed until 18 February 2006. The renovation included replacing
#982017