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106-717: Vereeniging is situated in the southern part of Gauteng Province, and forms the southern portion of the Pretoria-Witwatersrand-Vereeninging (PWV) conurbation, and its neighbors are Vanderbijlpark (to the west), Three Rivers (east), Meyerton (north) and Sasolburg (south). The city is currently one of the most important industrial manufacturing centres in South Africa, with its chief products being iron, steel, pipes, bricks, tiles and processed lime. The predominant language in Vereeniging

212-434: 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

318-430: 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

424-499: 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

530-561: A "Consolidated Urban Area" in Gauteng as having a population of 13.1 million as of January 2017 . The future governmental plans for the region indicate the gradual urbanisation and consolidation towards the creation of a megalopolis that connects these metros. The GCRO is a collaboration between the Universities of Johannesburg and Witwatersrand, the city of Johannesburg, Gauteng Provincial Government, and SALGA-Gauteng. The GCRO's purpose

636-454: 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

742-402: A fess wavy Or a barrulet wavy Tenne, the fess between in chief a thunderbolt between two picks, Or, and in base a steel pipe palewise proper between two cogwheels, also Or . In layman's terms, the design is a black shield displaying, from top to bottom, a golden heraldic thunderbolt between two picks, a wavy orange stripe edged in gold, and an upright golden pipe between two cogwheels. The crest

848-561: A large number of overseas companies requiring a commercial base in and gateway to Africa . Gauteng is home to the Johannesburg Stock Exchange , the largest stock exchange in Africa. Some of the largest companies in Africa and abroad are based in Gauteng, or have offices and branches there, such as Vodacom , MTN , Neotel , Microsoft South Africa and the largest Porsche Centre in the world. Although Gauteng

954-553: 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"

1060-475: 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

1166-413: A radio, 65.7% have a television, 15.1% own a computer, 62.1% have a refrigerator , and 45.1% have a mobile phone. 25.8% of the population aged 15–65 is unemployed. The median annual income of working adults aged 15–65 is R 23 539 ($ 3,483). Males have a median annual income of R 24 977 ($ 3,696) versus R 20 838 ($ 3,083) for females. Gauteng is the province with the second highest life expectancy in

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1272-471: 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 ,

1378-455: 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

1484-435: 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

1590-890: A village was surveyed on the two former farms. The Volksraad agreed to name it Vereeniging, a shortened version of the company's name. The Treaty of Vereeniging ending the Second Boer War (1899–1902) was negotiated here by delegates of the South African Republic , the Orange Free State , and the British Empire . During the conflict, a concentration camp was set up in the area by the British in September 1900, and by October 1901 it housed 185 men, 330 women, and 452 children. Conditions at

1696-513: A wide assortment of electronic and telecommunications systems. In 2007, this initiative was handed over to the Gauteng Department of Finance. In the 2013 national budget speech, it was announced that the Gauteng Department of Education would be granted over R 700 million to improve education and to alleviate issues concerning the overcrowding in schools, a shortage in teaching staff and transport for poor pupils. In 2017/2018,

1802-581: Is English followed closely by Sesotho language and Afrikaans . In 1879, George William Stow was commissioned by the Orange Free State government to look for coal deposits in the Bethlehem district With no deposits found he moved northwards to Maccauvlei on the Vaal River and then crossed the river to the Transvaal side. On the farm Leeuwkuil , he found a coal deposit twelve feet thick. But

1908-651: Is a superior court with general jurisdiction over the province. Johannesburg is also home to the Constitutional Court , South Africa's highest court, and to a branch of the Labour Court and Labour Appeal Court . Gauteng's southern border is the Vaal River , which separates it from the Free State . It also borders on North West to the west, Limpopo to the north, and Mpumalanga to

2014-473: Is a large informal transport sector in Gauteng, consisting of thousands of minibus taxis , which many of the urban and rural population makes use of. However, it is noted that taxis are often unsafe as their drivers ignore the rules of the road and the vehicles are often not roadworthy . The City of Johannesburg stated that: "major initiatives are under way to completely reform the taxi industry and provide more comfort and safety to customers." In March 2017, it

2120-596: Is also found in this province. Politically, it is the closest contested province between the ANC and the DA in South Africa. The name Gauteng is derived from Sotho-Tswana gauta , meaning 'gold'. There was a thriving gold industry in the province following the 1886 discovery of gold in Johannesburg . In Sesotho , Setswana and Sepedi the name Gauteng was used for Johannesburg and surrounding areas long before it

2226-646: 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

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2332-503: Is at a subtropical latitude, the climate is comparatively cooler, especially in Johannesburg , at 1,700 m (5,577 ft) above sea level ( Pretoria is at 1,330 m or 4,364 ft). Most precipitation occurs as brief afternoon thunderstorms; however, relative humidity never becomes uncomfortable. Winters are crisp and dry with frost occurring often in the southern areas. Snow is rare, but it has occurred on some occasions in

2438-407: 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

2544-499: 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

2650-474: 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

2756-429: Is home to the largest human-made urban forest in the world. There are 5 provincial reserves managed by the Gauteng Department of Agriculture, Conservation, Environment and Land Affairs: Gauteng is home to many stadiums and sporting grounds, notably Soccer City , Ellis Park Stadium , Odi Stadium , Loftus Versfeld Stadium , Lucas Moripe Stadium , Giant Stadium , Orlando Stadium , Johannesburg Stadium ,

2862-494: 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

2968-816: Is mostly dry savanna habitat. In the southern half of Gauteng, the Witwatersrand area is an older term describing a 120 km wide oblong-shaped conurbation from Randfontein in the West to Nigel in the East, named after the Witwatersrand , a geologically and economically important series of low ridges and their associated plateau that greater Johannesburg developed on. This area is also often referred to simply as "Witwatersrand", "the Rand" or "the Reef" (archaic, after

3074-401: 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

3180-552: Is one of the nine provinces of South Africa . Situated on the Highveld , Gauteng is the smallest province by land area in South Africa . Although Gauteng accounts for only 1.5% of the country's land area, it is the most populous province in South Africa , with more than a quarter (26%) of the national population; the provincial population was approximately 16.1 million, according to mid-year 2022 estimates. Highly urbanised,

3286-407: 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

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3392-399: Is reported that Gauteng alone has 4,7 million registered vehicles under the "GP" abbreviation via the eNatis system. Gauteng is a large center of learning in South Africa, and it has many universities and educational institutions of higher learning. In 2002, the Gauteng Department of Education founded an initiative called Gauteng Online in an attempt to get the entire province to utilize

3498-548: 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

3604-442: 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

3710-502: 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

3816-416: Is the smallest of South Africa's nine provinces—it covers a mere 1.5% of the country's total land area, the province is responsible for a third of South Africa's gross domestic product (GDP). Gauteng generates about 10% of the total GDP of sub-Saharan Africa and about 7% of total African GDP. Gauteng has the highest GDP and GDP per capita of all South Africa's provinces. Gauteng is also the province with

3922-418: 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 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

4028-556: Is to collect information and create a database on the Gauteng City Region to provide to government, lawmakers and civil society an informed understanding of the fastest urbanizing region in Southern Africa. Gauteng is considered the economic hub of South Africa and contributes heavily in the financial, manufacturing, transport, technology, and telecommunications sectors, among others. It also plays host to

4134-451: 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

4240-437: 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

4346-521: The Johannesburg metropolitan area. The Gauteng Province (as of May 2011) is divided into three metropolitan municipalities and two district municipalities . The district municipalities are in turn divided into six local municipalities : The former Metsweding district consisting of Nokeng Tsa Taemane and Kungwini in the North of the province was incorporated into Tshwane in 2011. As of

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4452-512: The 2022 census , Gauteng had a population of 15,099,422, an increase of 23.0% from the last census in 2011 . Despite being the smallest province by area, it has the highest population of any South African province, with 24.3% of the total South African population. As of 2022, there are 5,318,665 households in Gauteng. The population density is 831/km . The density of households is 155.86/km . About 22.1% of all households are made up of individuals. The average household size fell slightly between

4558-568: 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 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

4664-542: The N1 , N3 , N4 , N12 , N14 and the N17 . Johannesburg is quite dependent on freeways for transport in and around the city. The R21 , R24 , R59 , M1 and M2 all run through Johannesburg while the R80 connects Pretoria Central to Soshanguve. The Gauteng Freeway Improvement Project led to a large decrease in traffic congestion when construction finished 2011–2012. Cape Town , for

4770-625: The Second Boer War . The nearby town of Cullinan gained international acclaim in 1905 when the largest diamond ever discovered, the Cullinan Diamond , was mined there. Many events crucial to the anti- apartheid struggle happened in present-day Gauteng, such as the Freedom Charter of 1955, Women's March of 1956, Sharpeville massacre of 1960, the Rivonia Trial of 1963 and 1964, the little Rivonia Trial of 1964,

4876-621: The Soweto Uprising of 1976 and Sharpeville Six of 1984. The Apartheid Museum documents this era. Gauteng is governed by the Gauteng Provincial Legislature , a 73-person unicameral legislature elected by party-list proportional representation . The legislature elects one of its members as Premier of Gauteng to lead the executive, and the Premier appoints an Executive Council of up to 10 members of

4982-557: The Wanderers Stadium and SuperSport Park . Several teams from Gauteng play in the country's top-level association football (more commonly referred to as soccer) league, the Premier Soccer League (PSL), including Mamelodi Sundowns , SuperSport United , Kaizer Chiefs and Orlando Pirates . The national squad Bafana Bafana 's home stadium is Soccer City in Johannesburg. During the 2010 FIFA World Cup ,

5088-432: 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

5194-740: 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 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

5300-491: 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

5406-466: 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

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5512-410: The 2011 census and 2022 census, from 3.1 to 2.8 persons. The province's age distribution was 23.6% under the age of 15, 19.6% from 15 to 24, 37.9% from 25 to 44, 15.0% from 45 to 64, and 4.0% who are 65 years of age or older. The median age is 27 years. For every 100 females there are 101.2 males. For every 100 females age 18 and over, there are 102.3 males. According to the 2022 census , in Gauteng,

5618-570: 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

5724-603: 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

5830-606: The Emfuleni Local Municipality, along with Vanderbijlpark , Sharpeville, Sebokeng and the smaller Three Rivers. Various health services are available in Vereeniging. The majority of these services are located in or near the major medical centres. These include: Campuses of: The latest annual crime statistics for Vereeniging Police Precinct was issued by the South African Police Service (SAPS) in 2021. The SAPS crime report showed

5936-667: The Gauteng Provincial government spent R 42.4 billion on education which accounted for 38% the province's total expenditure. Although Gauteng province is dominated by the urban areas of Johannesburg and Pretoria, it has several nature reserves. Gauteng is home to the Cradle of Humankind UNESCO World Heritage Site which includes the Sterkfontein caves and the Wonder Cave Kromdraai . Johannesburg

6042-717: The Orange Free State government believed that the deposit was too far away and there was a lack of transport so turned down the idea of mining there. Stow settled in Kimberley to find a job, where he met Samuel Marks . After hearing Stow's story, Marks saw an opportunity to use the coal for energy generation at the Kimberley diamond fields. Marks formed De Zuid Afrikaanshe en Oranje Vrystaatsche Kolen and Mineralen Vereeniging (The South African and Orange Free State Coal and Mineral Association) and sent Stow to purchase

6148-894: The Southern Hemisphere Super Rugby championship: the Pretoria -based Bulls , and the Johannesburg -based Lions (previously the Cats). Three Gauteng-based teams play in the country's domestic competition, the Currie Cup : the Blue Bulls from Pretoria, the Golden Lions from Johannesburg and the Falcons from the East Rand . In 1995, South Africa hosted the 1995 Rugby World Cup and proceeded to win

6254-575: The Vaal River to where the concentration camp was, and a Garden of Remembrance is situated at Maccauvlei. All the British soldiers killed in and around Vereeniging during the war were re-buried on this site. Near Vereeniging is the predominantly black community of Sharpeville, Gauteng , the site of the Sharpeville massacre in 1960. Since 1999 its municipal services were provided by the Emfuleni Local Municipality . In 2018

6360-405: The area, with reserves being estimated at four billion tons. Other mines nearby extract fire- clay , silica and building stone. Vereeniging also has several Eskom thermal power plants that supply electricity to the nearby goldmines . In the census of 2001 the population of Vereeniging was recorded as 73,283. Vereeniging consists of 20 suburbs: Since 1999, Vereeniging has been part of

6466-450: 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,

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6572-614: The camp were very poor: drinking water was brought by cart from a fountain (there was no direct water supply although it was situated next to the Vaal River) and there were only 24 latrines. Most inmates lived in bell-tents but there was a dispensary and a school. The concentration camp was situated where the Mittal Steel plant (Vaal Works) is situated. Today, the Maccauvlei Golf Course is on the opposite side of

6678-709: 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

6784-464: 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

6890-540: The country in 2019 with females having a life expectancy of 69 years and males having a life expectancy of 64 years. Historically described as the PWV complex , the urban conurbation of Gauteng, referred to as the Gauteng City Region, contains the major urban populations of Johannesburg (7,860,781 as of 2011 ), Pretoria (1,763,336), Vereeniging (377,922), Evaton (605,504) and Soshanguve (728,063), coming to an urban population of over 11 million. Thomas Brinkhoff lists

6996-549: The country, and is the only sport to feature in the top two among all of South Africa's major ethnic/racial groups. The Highveld Lions represent both Gauteng and North West in the country's three domestic competitions—the first-class SuperSport Series , the List A one-day MTN Domestic Championship and the Twenty20 Standard Bank Pro 20 Series . Iron Iron is a chemical element ; it has

7102-401: 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 ,

7208-479: 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

7314-616: The early 19th century, when settlers originating from the Cape Colony defeated chief Mzilikazi and started establishing villages in the area. The city of Pretoria, established in 1855 as the capital of the South African Republic , witnessed rapid growth until the discovery of gold in the Witswatersrand area in 1886, which led to the founding of Johannesburg. Despite slower development compared to Johannesburg, Pretoria maintained significance, notably due to its pivotal role in

7420-522: The east. Gauteng is the only landlocked province of South Africa without a foreign border. Most of Gauteng is on the Highveld , a high-altitude grassland (circa 1,500 m or 4,921 ft above sea level). Between Johannesburg and Pretoria , there are low parallel ridges and undulating hills, some part of the Magaliesberg Mountains and the Witwatersrand . The north of the province is more subtropical , due to its lower altitude and

7526-424: The establishment of a province by that name, with the "V" sometimes standing for " Vaal Triangle " rather than Vereeniging. At the Sterkfontein caves, some of the oldest fossils of hominids have been discovered, such as Mrs. Ples and Little Foot . Events in this area were not written down until the 19th century; information from before that time is lost or difficult to confirm. The first records are from

7632-406: 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

7738-467: The farms where the coal was found. On 25 November 1880 he purchased the 12,000 acre farm Leeuwkuil for £5,000. Marks' agent J.G. Fraser also purchased the 6,000 acre Klipplaatdrift farm from Karl August Pistorius in October 1881 for £15,500. This was opposite the farm Maccauvlei . From 1881, coal was taken by ox-wagon to Kimberley, and by 1882 there was so much development around the mining area that

7844-439: The first ever world cup held by an African nation, Gauteng's stadia hosted many games. The first ever FIFA world cup match on African soil took place at Soccer City on 11 June 2010. Along with Soccer City, Loftus Versfeld Stadium and Ellis Park Stadium hosted matches in Gauteng. Rugby , or more accurately rugby union , is a popular sport in South Africa, and in Gauteng in particular. Two rugby teams from Gauteng participate in

7950-504: The first time in decades, is now the most congested city in South Africa. PUTCO , the largest commuter bus operator in South Africa, services the Gauteng area extensively. The bus rapid transit system Rea Vaya also serves to transport people from Johannesburg's southern neighbourhoods into and around the CBD . In an interview, Parks Tau stated that by 2040, Johannesburg will be dominated by pedestrians and public transport as opposed to

8056-676: The following information: Vereeniging established a municipality in 1912. By 1931, the town council had assumed an emblem depicting bridge across a river, and two clasped hands. The town council obtained a coat of arms from the College of Arms in October 1955, registered it with the Transvaal Provincial Administration in October 1957 and with the Bureau of Heraldry in June 1987. The arms were : Sable, on

8162-462: 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

8268-543: The gold reefs that precipitated the development of the area), and was the "W" in PWV , the initial name for Gauteng. It has traditionally been divided into the three areas of East Rand (governed by the Ekurhuleni Metropolitan Municipality ), Central Rand (approximately today's Johannesburg Municipality ) and West Rand . The climate is mostly influenced by altitude. Even though the province

8374-658: The high school level. Overall, 40.6% of residents have completed high school. 56.1% of housing units have a telephone and/or mobile phone in the dwelling, 41.5% have access to a phone nearby, and 2.3% have access that is not nearby or no access. 82.8% of households have a flush or chemical toilet. 84.2% have refuse removed by the municipality at least once a week and 2.6% have no rubbish disposal. 47.2% have running water inside their dwelling, 83.6% have running water on their property, and 97.5% have access to running water. 73.2% of households use electricity for cooking, 70.4% for heating, and 80.8% for lighting. 77.4% of households have

8480-511: The legislature to serve as heads of the various government departments. The provincial government is responsible for the topics allocated to it in the national constitution , including such fields as basic education, health, housing, social services, agriculture and environmental protection. The most recent election of the provincial legislature was held on 8 May 2019 , and the African National Congress (ANC) won 50.19% of

8586-453: 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

8692-446: 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

8798-407: 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 ,

8904-775: 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 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

9010-612: 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

9116-465: The most spoken languages at home were: 86.1% of residents are Christian, 4.3% have no religion , 1.6% are Muslim, 0.1% are Jewish, and 0.7% are Hindu . 6.0% stated Traditional African religions as their faith. 8.4% of residents aged 20 and over have received no schooling, 11.2% have had some primary, 5.5% have completed only primary school, 34.3% have had some high education, 28.0% have finished only high school, and 12.6% have an education higher than

9222-657: The most taxpayers and the highest average taxable income per taxpayer according to the South African Revenue Service . SANRAL , a parastatal, is responsible for the maintenance, development and management of all national road networks in South Africa. SANRAL is responsible for instituting the Gauteng Freeway Improvement Project, which was met with a lot of opposition due to the tolling of Gauteng motorists. Many important national routes run through Gauteng such as

9328-431: The municipality was placed under administration after years of wasteful practices and poor service delivery. In February 2022 it was reported that Vereeniging had 14 out-of-service police vehicles for visible policing, and only 20 operational vehicles. In December 2010 and January 2011 the southern part of Gauteng and Mpumulanga experienced a higher than normal rainfall. This resulted in the need to release more water from

9434-436: The nearby Vaal dam . As a consequence, parts of Vereeniging, Three Rivers and the rest of the towns downstream were flooded. The city's motto is Per Pacem ad Industriam ( Through Peace to Industry ). It is currently one of the most important industrial manufacturing centres in South Africa, with its chief products being iron , steel , pipes, bricks, tiles and processed lime . Several coal mines are also still situated in

9540-559: 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

9646-436: 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

9752-539: 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

9858-444: 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

9964-581: 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

10070-497: 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

10176-414: 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

10282-419: The province contains the country's largest city, Johannesburg . Gauteng is the wealthiest province in South Africa and is considered the financial hub of South Africa; the financial activity is mostly concentrated in Johannesburg. It also contains the administrative capital, Pretoria , and other large areas such as Midrand , Vanderbijlpark , Ekurhuleni and the affluent Sandton . The largest township, Soweto,

10388-437: 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

10494-564: 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 ,

10600-552: The tournament at Ellis Park Stadium on 24 June 1995. The events surrounding the world cup formed the basis of the story for the movie Invictus . Many South African universities take part in the Varsity Rugby league. Of these, the Gauteng universities include the University of Pretoria, the University of Johannesburg and the University of the Witwatersrand. Cricket is also widely popular among all cultural groups in

10706-600: The use of private transport or informal transport, such as minibus taxis. Gautrain and Metrorail both service the province's public transport sector where trains are concerned and Gautrain offers a bus service that transports commuters to and from various train stations and predetermined bus stops. Metrorail trains are considered one of the most cost-effective methods of transportation in and around Gauteng. The O. R. Tambo International Airport , Rand Airport , Lanseria International Airport , Wonderboom Airport and Grand Central Airport are located in Gauteng. There

10812-455: 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

10918-616: The vote and a 37-seat majority in the legislature. The official opposition is the Democratic Alliance , which won 27.45% of the vote and 20 seats. Other parties represented are the Economic Freedom Fighters with eleven seats and the Freedom Front Plus with three seats. The Inkatha Freedom Party and African Christian Democratic Party hold one seat each. Premier David Makhura of the ANC

11024-425: Was a dove of peace perched on two clasped hands; the supporters were a lion and a zebra standing on a grassy base strewn with veld flowers; and the motto was Per pacem ad industriam . Pretoria-Witwatersrand-Vereeniging Gauteng ( / x aʊ ˈ t ɛ ŋ / khow- TENG , Sotho: [xɑ́.úˈtʼèŋ̀] ; Sotho-Tswana for 'place of gold'; Zulu : eGoli or iGoli [îːˈɡóːlì] )

11130-415: Was adopted in 1994 as the official name of the province. Gauteng was formed from part of the old Transvaal Province after South Africa's first multiracial elections on 27 April 1994. It was initially called Pretoria – Witwatersrand – Vereeniging (PWV) and was renamed "Gauteng" on the 28th of June 1995, the same day two other provinces were renamed. The term "PWV" describing the region existed long before

11236-569: Was re-elected as premier on 22 May 2019, at the first meeting of the legislature after the general election. Makhura resigned from the position on 6 October 2022 and Panyaza Lesufi of the ANC was elected to replace him. In the 2024 South African general election , held on 29 May, the ANC received 34% of the vote, while the DA received 28%. The Gauteng Division of the High Court of South Africa , which has seats in Pretoria and Johannesburg,

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