109-795: The Morava Valley ( Serbian : Поморавље / Pomoravlje , pronounced [pɔmɔ̝̌raːvʎe̞] ), is a general term which in its widest sense marks valleys of any of three Morava rivers in Serbia : the West Morava ( West Morava Valley ), the South Morava ( South Morava Valley ) and the Great Morava ( Great Morava Valley ). In the narrow sense, the term is applied only to the Great Morava Valley ( Serbian : Велико Поморавље / Veliko Pomoravlje ). The Serbian term follows
218-750: A Cr-Cr quintuple bond (length 183.51(4) pm) has also been described. Extremely bulky monodentate ligands stabilize this compound by shielding the quintuple bond from further reactions. Chromium is the 21st most abundant element in Earth's crust with an average concentration of 100 ppm. Chromium compounds are found in the environment from the erosion of chromium-containing rocks, and can be redistributed by volcanic eruptions. Typical background concentrations of chromium in environmental media are: atmosphere <10 ng/m ; soil <500 mg/kg; vegetation <0.5 mg/kg; freshwater <10 μg/L; seawater <1 μg/L; sediment <80 mg/kg. Chromium
327-407: A branch splitting at Niš for Sofia , Bulgaria , which is actually a crossroads of the routes E75 and E80 which connects Portugal and Turkey . Since 2019, route has been turned into a highway. The South Morava Valley is also a railway crossroads: railway Belgrade-Niš-Skopje, trans-Balkan railway Peć - Prahovo , etc. The Great Morava Valley ( Serbian : Велико Поморавље / Veliko Pomoravlje )
436-414: A change to less toxic chromium(III) compounds. The mineral crocoite (which is also lead chromate PbCrO 4 ) was used as a yellow pigment shortly after its discovery. After a synthesis method became available starting from the more abundant chromite, chrome yellow was, together with cadmium yellow , one of the most used yellow pigments. The pigment does not photodegrade, but it tends to darken due to
545-525: A critical material during the emergency". The United States likewise considered chromium "essential for the German war industry" and made intense diplomatic efforts to keep it out of the hands of Nazi Germany . The high hardness and corrosion resistance of unalloyed chromium makes it a reliable metal for surface coating; it is still the most popular metal for sheet coating, with its above-average durability, compared to other coating metals. A layer of chromium
654-414: A high infrared and visible light reflectance. Chromium metal in air is passivated : it forms a thin, protective surface layer of chromium oxide with the corundum structure. Passivation can be enhanced by short contact with oxidizing acids like nitric acid . Passivated chromium is stable against acids. Passivation can be removed with a strong reducing agent that destroys the protective oxide layer on
763-472: A large floodplain, frequently flooded by the West Morava due to the extreme fluctuation of its discharge, The West Morava Valley was always an agricultural area, but in the second half of 20th century industry also developed in all major towns along the river. Fertile land in the valley is best for grains and orchards. Corn is being cultivated in the Čačak-Kraljevo depression, while wheat is being grown in
872-490: A larger chromite deposit was discovered near Baltimore , United States, which quickly met the demand for tanning salts much more adequately than the crocoite that had been used previously. This made the United States the largest producer of chromium products until the year 1848, when larger deposits of chromite were uncovered near the city of Bursa , Turkey. With the development of metallurgy and chemical industries in
981-422: A sequence of valleys (depressions) and gorges. Sections include: The West Morava Valley comprises several historical and geographical regions of Serbia, which are its own geographical sub-regions. From west to east, they are: The West Morava Valley had a population of 531,978 inhabitants by the 2002 census of population, which gives an average population density of 102 inhabitants per square kilometer. The largest
1090-422: A solution of polyvinyl butyral . An 8% solution of phosphoric acid in solvent was added just before application. It was found that an easily oxidized alcohol was an essential ingredient. A thin layer of about 10–15 μm was applied, which turned from yellow to dark green when it was cured. There is still a question as to the correct mechanism. Chrome green is a mixture of Prussian blue and chrome yellow , while
1199-547: Is Cr with a half-life of 27.7 days. All of the remaining radioactive isotopes have half-lives that are less than 24 hours and the majority less than 1 minute. Chromium also has two metastable nuclear isomers . The primary decay mode before the most abundant stable isotope, Cr, is electron capture and the primary mode after is beta decay . Cr is the radiogenic decay product of Mn (half-life 3.74 million years). Chromium isotopes are typically collocated (and compounded) with manganese isotopes. This circumstance
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#17327724308101308-436: Is Torlakian in southeastern Serbia, which is transitional to Macedonian and Bulgarian . Serbian is practically the only European standard language whose speakers are fully functionally digraphic , using both Cyrillic and Latin alphabets. The Serbian Cyrillic alphabet was devised in 1814 by Serbian linguist Vuk Karadžić , who created it based on phonemic principles. The Latin alphabet used for Serbian ( latinica )
1417-428: Is 125 nanoohm - meters . Chromium has a high specular reflection in comparison to other transition metals. In infrared , at 425 μm , chromium has a maximum reflectance of about 72%, reducing to a minimum of 62% at 750 μm before rising again to 90% at 4000 μm. When chromium is used in stainless steel alloys and polished , the specular reflection decreases with the inclusion of additional metals, yet
1526-409: Is 8.5, which means that it can scratch samples of quartz and topaz , but can be scratched by corundum . Chromium is highly resistant to tarnishing , which makes it useful as a metal that preserves its outermost layer from corroding , unlike other metals such as copper , magnesium , and aluminium . Chromium has a melting point of 1907 °C (3465 °F), which is relatively low compared to
1635-580: Is Cr(VI). Chromium minerals as pigments came to the attention of the west in the eighteenth century. On 26 July 1761, Johann Gottlob Lehmann found an orange-red mineral in the Beryozovskoye mines in the Ural Mountains which he named Siberian red lead . Though misidentified as a lead compound with selenium and iron components, the mineral was in fact crocoite with a formula of PbCrO 4 . In 1770, Peter Simon Pallas visited
1744-461: Is a "substance of very high concern" (SVHC). Gaseous chromium has a ground-state electron configuration of [ Ar ] 3d 4s . It is the first element in the periodic table whose configuration violates the Aufbau principle . Exceptions to the principle also occur later in the periodic table for elements such as copper , niobium and molybdenum . Chromium is the first element in the 3d series where
1853-483: Is a strong oxidizing agent. Compounds of chromium(V) are rather rare; the oxidation state +5 is only realized in few compounds but are intermediates in many reactions involving oxidations by chromate. The only binary compound is the volatile chromium(V) fluoride (CrF 5 ). This red solid has a melting point of 30 °C and a boiling point of 117 °C. It can be prepared by treating chromium metal with fluorine at 400 °C and 200 bar pressure. The peroxochromate(V)
1962-576: Is able to be highly polished while resisting tarnishing . Polished chromium reflects almost 70% of the visible spectrum , and almost 90% of infrared light . The name of the element is derived from the Greek word χρῶμα, chrōma , meaning color , because many chromium compounds are intensely colored. Industrial production of chromium proceeds from chromite ore (mostly FeCr 2 O 4 ) to produce ferrochromium , an iron-chromium alloy, by means of aluminothermic or silicothermic reactions . Ferrochromium
2071-660: Is also known for the cattle and sheep . Walnuts and almonds are produced as well. Region is also known for producing melons and watermelons . Textile industry is developed, because the region produces much linen . Sunflower seeds provide vegetable oil . Water from South Morava is also used for the irrigation, due to parts of the region being semi-arid . The mountains surrounding the region are rich in minerals and ores. The mountain of Besna Kobila has findings of zinc , lead and silver . Other findings include chromium , antimony , graphite , lithium and tungsten . Oil shales are found near Leskovac and Aleksinac. Aleksinac
2180-496: Is also part of a large Aleksinac coal basin, while lignite is abundant in the area. Though South Morava has a significant potential for electricity production, it has not been dammed, though some parts of its watershed on the east (Vlasina, Vrla) have a series of hydro electrical plants (Vrla I, II, III and IV). Area is rich in mineral springs with many spas: Vranjska Banja, Bujanovčaka Banja, Ribarska Banja, Kulinska Banja, Klokot Banja, etc. There are several large industrial centers in
2289-451: Is another example of the +5 oxidation state. Potassium peroxochromate (K 3 [Cr(O 2 ) 4 ]) is made by reacting potassium chromate with hydrogen peroxide at low temperatures. This red brown compound is stable at room temperature but decomposes spontaneously at 150–170 °C. Compounds of chromium(IV) are slightly more common than those of chromium(V). The tetrahalides, CrF 4 , CrCl 4 , and CrBr 4 , can be produced by treating
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#17327724308102398-527: Is based on the most widespread dialect of Serbo-Croatian, Shtokavian (more specifically on the dialects of Šumadija-Vojvodina and Eastern Herzegovina ), which is also the basis of standard Croatian , Bosnian , and Montenegrin varieties and therefore the Declaration on the Common Language of Croats, Bosniaks, Serbs, and Montenegrins was issued in 2017. The other dialect spoken by Serbs
2507-591: Is closer to the Kajkavian and Chakavian dialects of Serbo-Croatian ). Speakers by country: Serbian was the official language of Montenegro until October 2007, when the new Constitution of Montenegro replaced the Constitution of 1992. Amid opposition from pro-Serbian parties, Montenegrin was made the sole official language of the country, and Serbian was given the status of a language in official use along with Bosnian , Albanian , and Croatian . In
2616-401: Is composed of four stable isotopes ; Cr, Cr, Cr and Cr, with Cr being the most abundant (83.789% natural abundance ). Cr is observationally stable , as it is theoretically capable of decaying to Ti via double electron capture with a half-life of no less than 1.3 × 10 years. Twenty-five radioisotopes have been characterized, ranging from Cr to Cr; the most stable radioisotope
2725-414: Is deposited on pretreated metallic surfaces by electroplating techniques. There are two deposition methods: thin, and thick. Thin deposition involves a layer of chromium below 1 μm thickness deposited by chrome plating , and is used for decorative surfaces. Thicker chromium layers are deposited if wear-resistant surfaces are needed. Both methods use acidic chromate or dichromate solutions. To prevent
2834-447: Is formed, which can be stabilized as an ether adduct CrO 5 ·OR 2 . Chromic acid has the hypothetical formula H 2 CrO 4 . It is a vaguely described chemical, despite many well-defined chromates and dichromates being known. The dark red chromium(VI) oxide CrO 3 , the acid anhydride of chromic acid, is sold industrially as "chromic acid". It can be produced by mixing sulfuric acid with dichromate and
2943-557: Is in the area of Čačak (184 per km) and the smallest in the neighboring area of Lučani (54 per km). Despite large urban centers, population has been depopulating for almost two decades. The population of the Morava Valley by the official censuses of population: Largest settlements of the West Morava Valley in 2002 were: The West Morava Valley is economically the most developed of all three Morava river valleys. Being
3052-619: Is located near Svilajnac. One of three Serbian cement plants is located in Popovac (formerly "Novi Popovac", in 2002 bought by one of the Swiss cement company Holcim ). The Great Morava Valley was always an important traffic route. In Roman times, it was the location of Via Militaris , while in the medieval period Constantinople road ran through. Today, it makes a section of the European route E75 (Belgrade-Niš highway) which continues into
3161-626: Is mined as chromite (FeCr 2 O 4 ) ore. About two-fifths of the chromite ores and concentrates in the world are produced in South Africa, about a third in Kazakhstan, while India, Russia, and Turkey are also substantial producers. Untapped chromite deposits are plentiful, but geographically concentrated in Kazakhstan and southern Africa. Although rare, deposits of native chromium exist. The Udachnaya Pipe in Russia produces samples of
3270-530: Is shows that it was in accord with its time; for example, the Serbian Alexandride , a book about Alexander the Great , and a translation of Tristan and Iseult into Serbian. Although not belonging to the literature proper, the corpus of Serbian literacy in the 14th and 15th centuries contains numerous legal, commercial and administrative texts with marked presence of Serbian vernacular juxtaposed on
3379-604: Is stable at neutral pH . Some other notable chromium(II) compounds include chromium(II) oxide CrO , and chromium(II) sulfate CrSO 4 . Many chromium(II) carboxylates are known. The red chromium(II) acetate (Cr 2 (O 2 CCH 3 ) 4 ) is somewhat famous. It features a Cr-Cr quadruple bond . A large number of chromium(III) compounds are known, such as chromium(III) nitrate , chromium(III) acetate , and chromium(III) oxide . Chromium(III) can be obtained by dissolving elemental chromium in acids like hydrochloric acid or sulfuric acid , but it can also be formed through
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3488-576: Is still high in comparison with other alloys. Between 40% and 60% of the visible spectrum is reflected from polished stainless steel. The explanation on why chromium displays such a high turnout of reflected photon waves in general, especially the 90% in infrared, can be attributed to chromium's magnetic properties. Chromium has unique magnetic properties; it is the only elemental solid that shows antiferromagnetic ordering at room temperature and below. Above 38 °C, its magnetic ordering becomes paramagnetic . The antiferromagnetic properties, which cause
3597-645: Is the standardized variety of the Serbo-Croatian language mainly used by Serbs . It is the official and national language of Serbia , one of the three official languages of Bosnia and Herzegovina and co-official in Montenegro and Kosovo . It is a recognized minority language in Croatia , North Macedonia , Romania , Hungary , Slovakia , and the Czech Republic . Standard Serbian
3706-556: Is the valley of the Great Morava . It is often referred to only as the Morava Valley ( Serbian : Поморавље / Pomoravlje ; Pomoravlje District is located in the southern area of the Great Morava Valley). At the beginning, it is bounded by the mountains of Juhor on the west and Kučaj on the east. In the later section, the Morava Valley gets much wider, with only smaller hills bounding it and opens widely to
3815-483: Is the valley of the West Morava . It is the southernmost Peripannonic region of Serbia. It is parallel, latitudinally elongated, in the west-to-east direction, opposed to the meridian , south-to-north direction of South Morava Valley and Great Morava Valley. It occupies and area of 5,220 square kilometers and generally corresponds to the valley of the West Morava River and sections of its watershed around
3924-435: Is the only general historical dictionary of Serbo-Croatian. Its first editor was Đuro Daničić , followed by Pero Budmani and the famous Vukovian Tomislav Maretić . The sources of this dictionary are, especially in the first volumes, mainly Štokavian . There are older, pre-standard dictionaries, such as the 1791 German–Serbian dictionary or 15th century Arabic-Persian-Greek-Serbian Conversation Textbook . The standard and
4033-449: Is then used to produce alloys such as stainless steel. Pure chromium metal is produced by a different process: roasting and leaching of chromite to separate it from iron, followed by reduction with carbon and then aluminium . Trivalent chromium (Cr(III)) occurs naturally in many foods and is sold as a dietary supplement , although there is insufficient evidence that dietary chromium provides nutritional benefit to people. In 2014,
4142-523: Is used where high temperature would normally cause carburization , oxidation or corrosion . Incoloy 800 "is capable of remaining stable and maintaining its austenitic structure even after long time exposures to high temperatures". Nichrome is used as resistance wire for heating elements in things like toasters and space heaters. These uses make chromium a strategic material . Consequently, during World War II, U.S. road engineers were instructed to avoid chromium in yellow road paint, as it "may become
4251-590: Is useful in isotope geology . Manganese-chromium isotope ratios reinforce the evidence from Al and Pd concerning the early history of the Solar System . Variations in Cr/ Cr and Mn/Cr ratios from several meteorites indicate an initial Mn/ Mn ratio that suggests Mn-Cr isotopic composition must result from in-situ decay of Mn in differentiated planetary bodies. Hence Cr provides additional evidence for nucleosynthetic processes immediately before coalescence of
4360-412: Is valued for its high corrosion resistance and hardness . A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel . Stainless steel and chrome plating ( electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that
4469-849: The Universal Declaration of Human Rights in Serbian, written in the Cyrillic script : Сва људска бића рађају се слободна и једнака у достојанству и правима. Она су обдарена разумом и свешћу и треба једни према другима да поступају у духу братства. Article 1 of the Universal Declaration of Human Rights in Serbian, written in the Latin alphabet : Sva ljudska bića rađaju se slobodna i jednaka u dostojanstvu i pravima. Ona su obdarena razumom i svešću i treba jedni prema drugima da postupaju u duhu bratstva. Article 1 of
Morava Valley - Misplaced Pages Continue
4578-605: The Danube and Banat region, across the river. It covers an area of 4,360 square milometers, which is over 70% of the entire Great Morava watershed. The Great Morava Valley is a valley region of the middle, Peripannonic Serbia. In the Neogene, it was a deep bay ("Morava Bay") of the inner Pannonian Sea , which flowed off through the Đerdap gorge 600,000 years ago. As the sea withdrew, the Great Morava cut in its flow through
4687-594: The European Food Safety Authority concluded that research on dietary chromium did not justify it to be recognized as an essential nutrient . While chromium metal and Cr(III) ions are considered non-toxic, chromate and its derivatives, often called " hexavalent chromium ", is toxic and carcinogenic . According to the European Chemicals Agency (ECHA), chromium trioxide that is used in industrial electroplating processes
4796-631: The Proto-Slavic language . There are many loanwords from different languages, reflecting cultural interaction throughout history. Notable loanwords were borrowed from Greek, Latin, Italian, Turkish, Hungarian, English, Russian, German, Czech and French. Serbian literature emerged in the Middle Ages , and included such works as Miroslavljevo jevanđelje ( Miroslav's Gospel ) in 1186 and Dušanov zakonik ( Dušan's Code ) in 1349. Little secular medieval literature has been preserved, but what there
4905-511: The Universal Declaration of Human Rights in English: All human beings are born free and equal in dignity and rights. They are endowed with reason and conscience and should act towards one another in a spirit of brotherhood. Chromium Chromium is a chemical element ; it has symbol Cr and atomic number 24. It is the first element in group 6 . It is a steely-grey, lustrous , hard, and brittle transition metal . Chromium
5014-457: The official script of Serbia's administration by the 2006 Constitution . The Latin script continues to be used in official contexts, although the government has indicated its desire to phase out this practice due to national sentiment. The Ministry of Culture believes that Cyrillic is the "identity script" of the Serbian nation. However, the law does not regulate scripts in standard language , or standard language itself by any means, leaving
5123-488: The 2023 Montenegrin census, 43.18% declared Serbian to be their native language, while Montenegrin was declared by 34.52% of the population. Standard Serbian language uses both Cyrillic ( ћирилица , ćirilica ) and Latin script ( latinica , латиница ). Serbian is a rare example of synchronic digraphia , a situation where all literate members of a society have two interchangeable writing systems available to them. Media and publishers typically select one alphabet or
5232-445: The 3d electrons start to sink into the core; they thus contribute less to metallic bonding , and hence the melting and boiling points and the enthalpy of atomisation of chromium are lower than those of the preceding element vanadium . Chromium(VI) is a strong oxidising agent in contrast to the molybdenum (VI) and tungsten (VI) oxides. Chromium is the third hardest element after carbon ( diamond ) and boron . Its Mohs hardness
5341-601: The Cr-centered Keggin anion [α-CrW 12 O 40 ] . Chromium(III) hydroxide (Cr(OH) 3 ) is amphoteric , dissolving in acidic solutions to form [Cr(H 2 O) 6 ] , and in basic solutions to form [Cr(OH) 6 ] . It is dehydrated by heating to form the green chromium(III) oxide (Cr 2 O 3 ), a stable oxide with a crystal structure identical to that of corundum . Chromium(VI) compounds are oxidants at low or neutral pH. Chromate anions ( CrO 4 ) and dichromate (Cr 2 O 7 ) anions are
5450-630: The Great Morava Valley is the granary of Central Serbia. The Great Morava agricultural region covers much larger area than the Great Morava Valley or even the watershed of the Great Morava: regions of Mlava and Pek on the east ( Braničevo District ) and almost half of Šumadija , on the west. Main products in the valley are corn, wheat, sugar beet and sunflower. Hilly areas surrounding the valley are producing fruits, grapes (Smederevo), fodder plants and livestock. Braničevo region has
5559-525: The Great Morava and West Morava are considered the eastern and southern borders, respectively, of the super-region of Šumadija , they largely overlap with it in these areas. The South Morava Valley had a population of 545,517 inhabitants by the 2002 census of population, with an average population density of 125 inhabitants per square kilometer. Extremes include Smederevo, with 230 per km, and Despotovac , with 41 per km. Despite being developed as an agricultural and industrial region, it has been depopulating for
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#17327724308105668-453: The Kruševac depression. Dragačevo region is known for the potato production. Čačak area is known for the plum growing, Požega is known for the apples ("budimka" brand) and Župa region around Aleksandrovac is famous for white grapes and wine production. The reservoir Parmenac near Čačak is created for the purpose of irrigation and further fertilization of the land. Also, out of all three sections of
5777-881: The Latin alphabet whereas 36% favors the Cyrillic one. Latin script has become more and more popular in Serbia, as it is easier to input on phones and computers. The sort order of the ćirilica ( ћирилица ) alphabet: The sort order of the latinica ( латиница ) alphabet: Serbian is a highly inflected language , with grammatical morphology for nouns, pronouns and adjectives as well as verbs. Serbian nouns are classified into three declensional types, denoted largely by their nominative case endings as "-a" type, "-i" and "-e" type. Into each of these declensional types may fall nouns of any of three genders : masculine, feminine or neuter. Each noun may be inflected to represent
5886-410: The Latin script predominates, although both scripts are commonly seen. The Serbian government has encouraged increasing the use of Cyrillic in these contexts. Larger signs, especially those put up by the government, will often feature both alphabets; if the sign has English on it, then usually only Cyrillic is used for the Serbian text. A survey from 2014 showed that 47% of the Serbian population favors
5995-450: The Latin script tends to imply a cosmopolitan or neutral attitude, while Cyrillic appeals to a more traditional or vintage sensibility. In media, the public broadcaster, Radio Television of Serbia , predominantly uses the Cyrillic script whereas the privately run broadcasters, like RTV Pink , predominantly use the Latin script. Newspapers can be found in both scripts. In the public sphere, with logos, outdoor signage and retail packaging,
6104-454: The Morava Valley, the West Morava Valley is the most forested one. The West Morava Valley is rich in ores . It includes the mining of brown coal ("West Morava's coal basin"), hard coal , asbestos , magnesite , chromium , etc. As a result, the industry is very developed with a string of heavily industrialized towns: Požega, Čačak, Kraljevo, Trstenik and Kruševac. With the valley of the Ibar,
6213-832: The Solar System. Cr has been posited as a proxy for atmospheric oxygen concentration. Chromium is a member of group 6 , of the transition metals . The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium are rare, but do nevertheless occasionally exist. Many Cr(0) complexes are known. Bis(benzene)chromium and chromium hexacarbonyl are highlights in organochromium chemistry . Chromium(II) compounds are uncommon, in part because they readily oxidize to chromium(III) derivatives in air. Water-stable chromium(II) chloride CrCl 2 that can be made by reducing chromium(III) chloride with zinc. The resulting bright blue solution created from dissolving chromium(II) chloride
6322-949: The South Morava Valley (2011 census; * denotes 2002 data): The South Morava Valley is fertile and thus is the major fruit and vegetable growing area in Serbia, especially the areas of Vranje, which is specialized in the production of peppers, and Leskovac, important tomato producing region, but other early vegetables as well. Vranje is also known for floriculture . The area is also producing grains (corn in Vranje and Leskovac, wheat in Leskovac and Aleksinac- Niš region), figs , fruits (cherries in Vranje, grapes in Leskovac) and industrial plants (sugar beet in Aleksinac- Niš, tobacco in Aleksinac- Niš, Vranje and Leskovac). Leskovac
6431-719: The South Morava Valley. It also a route for the Belgrade-Niš railway. In past times, the Great Morava used to be navigable, but due to the huge amounts of materials which are brought by the South Morava, as a result of extreme erosion in its watershed, the river bed of the Great Morava is literally being covered up so the river is not navigable today. Only some 3 kilometers near its mouth into the Danube can be used for navigation. Serbian language Serbian ( српски / srpski , pronounced [sr̩̂pskiː] )
6540-470: The West Morava has a huge potential in electricity production. Hydroelectric power plants Ovčar (6 MW) and Međuvršje (7 MW) with artificial lakes are built near Čačak, in the Ovčar-Kablar gorge, so as the lakes Parmenac (also on Morava) and Ćelije (on Rasina). The entire river valley is a natural route for both roads and railways connecting eastern, central and western Serbia, so traffic is also important for
6649-560: The Western world, the need for chromium increased. Chromium is also famous for its reflective, metallic luster when polished. It is used as a protective and decorative coating on car parts, plumbing fixtures, furniture parts and many other items, usually applied by electroplating . Chromium was used for electroplating as early as 1848, but this use only became widespread with the development of an improved process in 1924. Approximately 28.8 million metric tons (Mt) of marketable chromite ore
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#17327724308106758-520: The area has vast finding of coal, near Kostolac (Kostolac-Podunavlje Basin; brown coal ), in the valley of Resavica (Despotovac Basin; brown coal at Makvište and Resavica, lignite at Despotovac) and near Ćuprija (Senje Basin; brown coal). Also, the Great Morava Valley has only a few mineral springs (Lućička Banja, Stragarska Banja, etc.). Major industrial centers are Jagodina, Smederevo, Smederevska Palanka and Ćuprija, followed by Paraćin, Požarevac and Velika Plana. Thermal power plant "Morava" (125 MW )
6867-655: The area's density is in general smaller, average density being enlarged by the large centers like the city of Niš (430 per km) and Leskovac. The South Morava Valley has been known for rural depopulation and stagnation almost for the last five decades while the cities grew larger. The population of the Morava Valley by the official censuses of population and latest estimates (including the valley in narrower sense: municipalities of Preševo, Bujanovac, Vladičin Han, Vlasotince, Doljevac, Merošina, Gadžin Han, Aleksinac and Ražanj, and cities of Vranje, Leskovac and Niš): The largest settlements of
6976-483: The beginning of the 13th century, the entire official correspondence of Dubrovnik with states in the hinterland was conducted in Serbian. In the mid-15th century, Serbia was conquered by the Ottoman Empire and for the next 400 years there was no opportunity for the creation of secular written literature. However, some of the greatest literary works in Serbian come from this time, in the form of oral literature,
7085-439: The choice of script as a matter of personal preference and to the free will in all aspects of life (publishing, media, trade and commerce, etc.), except in government paperwork production and in official written communication with state officials, which have to be in Cyrillic. Traffic signs and directional signs, and place names, on main or international roads are to be written with both Cyrillic and Latin script To most Serbians,
7194-446: The chromate stored in the chromate conversion coating, which is able to migrate to local defects, are the benefits of this coating method. Because of environmental and health regulations on chromates, alternative coating methods are under development. Chromic acid anodizing (or Type I anodizing) of aluminium is another electrochemical process that does not lead to the deposition of chromium, but uses chromic acid as an electrolyte in
7303-458: The chromium atoms to temporarily ionize and bond with themselves, are present because the body-centric cubic's magnetic properties are disproportionate to the lattice periodicity . This is due to the magnetic moments at the cube's corners and the unequal, but antiparallel, cube centers. From here, the frequency-dependent relative permittivity of chromium, deriving from Maxwell's equations and chromium's antiferromagnetism , leaves chromium with
7412-445: The deep shade of red pigment chrome red , which is simply lead chromate with lead(II) hydroxide (PbCrO 4 ·Pb(OH) 2 ). A very important chromate pigment, which was used widely in metal primer formulations, was zinc chromate, now replaced by zinc phosphate. A wash primer was formulated to replace the dangerous practice of pre-treating aluminium aircraft bodies with a phosphoric acid solution. This used zinc tetroxychromate dispersed in
7521-452: The drained bay, almost for 500 meters. The region is 120 kilometers long and up to 40 kilometers wide. Altitudes vary from 75 meters on the north to 130 meters on the south. It has a tempered continental climate with not much rainfall but frequent floods. Composite valley of the Great Morava has three main sections. Regions, which partially or completely make the Great Morava Valley, include Jasenica , Lepenica , Resava and Temnić . Because
7630-580: The early 19th century, Vuk Stefanović Karadžić promoted the spoken language of the people as a literary norm. The dialects of Serbo-Croatian , regarded Serbian (traditionally spoken in Serbia), include: Vuk Karadžić 's Srpski rječnik , first published in 1818, is the earliest dictionary of modern literary Serbian. The Rječnik hrvatskoga ili srpskoga jezika (I–XXIII), published by the Yugoslav Academy of Sciences and Arts from 1880 to 1976,
7739-416: The eastern border of the region. The South Morava Valley ( Serbian : Јужно Поморавље / Južno Pomoravlje ) is the valley of the South Morava . It is the southernmost region of Serbia, bordering North Macedonia . It is meridionally elongated, in the south-to-north direction. In the narrower sense, as a valley of the South Morava, it occupies an area of 4,800 km, of which 1,660 km on Kosovo and
7848-541: The economy of the region. Tourism is almost entirely based on mineral spas, as the West Morava Valley is dubbed "First spa region of Serbia". Best known spas include Vrnjačka Banja, Mataruška Banja, Bogutovačka Banja , Ovčar Banja, Vička Banja , Gornja Trepča , etc. Additional interests are the Goč mountain and medieval Serbian Orthodox monasteries of Žiča, Kalenić , Lazarica , Ljubostinja , Naupara , etc. One of top mountain resorts of Serbia, Tara and Zlatibor , are marking
7957-419: The energy-consuming change in oxidation state, the use of chromium(III) sulfate is under development; for most applications of chromium, the previously established process is used. In the chromate conversion coating process, the strong oxidative properties of chromates are used to deposit a protective oxide layer on metals like aluminium, zinc, and cadmium. This passivation and the self-healing properties of
8066-546: The formation of chromium(III) oxide. It has a strong color, and was used for school buses in the United States and for the postal services (for example, the Deutsche Post ) in Europe. The use of chrome yellow has since declined due to environmental and safety concerns and was replaced by organic pigments or other alternatives that are free from lead and chromium. Other pigments that are based around chromium are, for example,
8175-515: The formation of discrete, stable, metal, carbide particles at the grain boundaries. For example, Inconel 718 contains 18.6% chromium. Because of the excellent high-temperature properties of these nickel superalloys , they are used in jet engines and gas turbines in lieu of common structural materials. ASTM B163 relies on chromium for condenser and heat-exchanger tubes, while castings with high strength at elevated temperatures that contain chromium are standardised with ASTM A567. AISI type 332
8284-704: The general manner of coining river valley names in Serbian using the prefix po- and suffix -je , meaning literally "(land) along the Morava". Morava valley lies in the central Balkans , at the crossroads which lead eastwards, towards the Black Sea and Asia Minor , and further south, down the Vardar River into the Aegean Sea . The West Morava Valley ( Serbian : Западно Поморавље / Zapadno Pomoravlje )
8393-496: The insoluble iron oxide. The chromate is converted by sulfuric acid into the dichromate. The dichromate is converted to the chromium(III) oxide by reduction with carbon and then reduced in an aluminothermic reaction to chromium. The creation of metal alloys account for 85% of the available chromium's usage. The remainder of chromium is used in the chemical , refractory , and foundry industries. The strengthening effect of forming stable metal carbides at grain boundaries, and
8502-401: The largest production of beans in Serbia. Horse stud farm Ljubičevo is located near Požarevac. In the past centuries the Great Morava Valley was famous for its vast forest, but today it is almost entirely turned into an arable land. Unlike the West Morava Valley and South Morava Valley, the Great Morava Valley has almost no ores or minerals, except for the cement marl near Paraćin. But
8611-539: The last few decades. The population of the Morava Valley by the official censuses of population: In the 1980s plans were made to join towns of Jagodina, Paraćin and Ćuprija into the first planned conurbation in Yugoslavia , including inter-city tramway lines, etc., but the idea was dropped later. The largest settlements of the Great Morava Valley in 2002 were: With very fertile arable land, almost endless gardens, orchards and vineyards and its intensive agriculture,
8720-570: The major 'levels' of language shows that BCS is clearly a single language with a single grammatical system." It has lower intelligibility with the Eastern South Slavic languages Bulgarian and Macedonian , than with Slovene (Slovene is part of the Western South Slavic subgroup, but there are still significant differences in vocabulary, grammar and pronunciation to the standardized forms of Serbo-Croatian, although it
8829-530: The majority of transition metals. However, it still has the second highest melting point out of all the period 4 elements , being topped by vanadium by 3 °C (5 °F) at 1910 °C (3470 °F). The boiling point of 2671 °C (4840 °F), however, is comparatively lower, having the fourth lowest boiling point out of the Period 4 transition metals alone behind copper , manganese and zinc . The electrical resistivity of chromium at 20 °C
8938-605: The matrix of Serbian Church Slavonic . By the beginning of the 14th century the Serbo-Croatian language, which was so rigorously proscribed by earlier local laws, becomes the dominant language of the Republic of Ragusa . However, despite her wealthy citizens speaking the Serbo-Croatian dialect of Dubrovnik in their family circles, they sent their children to Florentine schools to become perfectly fluent in Italian. Since
9047-428: The metal. Chromium metal treated in this way readily dissolves in weak acids. The surface chromia Cr 2 O 3 scale, is adherent to the metal. In contrast, iron forms a more porous oxide which is weak and flakes easily and exposes fresh metal to the air, causing continued rusting . At room temperature, the chromia scale is a few atomic layers thick, growing in thickness by outward diffusion of metal ions across
9156-407: The most notable form being epic poetry . The epic poems were mainly written down in the 19th century, and preserved in oral tradition up to the 1950s, a few centuries or even a millennium longer than by most other "epic folks". Goethe and Jacob Grimm learned Serbian in order to read Serbian epic poetry in the original. By the end of the 18th century, the written literature had become estranged from
9265-426: The native metal. This mine is a kimberlite pipe, rich in diamonds , and the reducing environment helped produce both elemental chromium and diamonds. The relation between Cr(III) and Cr(VI) strongly depends on pH and oxidative properties of the location. In most cases, Cr(III) is the dominating species, but in some areas, the ground water can contain up to 39 μg/L of total chromium, of which 30 μg/L
9374-415: The noun they modify, but must agree in number, gender and case with the modified noun. Serbian verbs are conjugated in four past forms— perfect , aorist , imperfect , and pluperfect —of which the last two have a very limited use (imperfect is still used in some dialects, but the majority of native Serbian speakers consider it archaic), one future tense (also known as the first future tense, as opposed to
9483-517: The noun's grammatical case , of which Serbian has seven: Nouns are further inflected to represent the noun's number , singular or plural. Pronouns, when used, are inflected along the same case and number morphology as nouns. Serbian is a pro-drop language , meaning that pronouns may be omitted from a sentence when their meaning is easily inferred from the text. In cases where pronouns may be dropped, they may also be used to add emphasis. For example: Adjectives in Serbian may be placed before or after
9592-682: The only completed etymological dictionary of Serbian is the " Skok ", written by the Croatian linguist Petar Skok : Etimologijski rječnik hrvatskoga ili srpskoga jezika ("Etymological Dictionary of Croatian or Serbian"). I-IV. Zagreb 1971–1974. There is also a new monumental Etimološki rečnik srpskog jezika (Etymological Dictionary of Serbian). So far, two volumes have been published: I (with words on A-), and II (Ba-Bd). There are specialized etymological dictionaries for German, Italian, Croatian, Turkish, Greek, Hungarian, Russian, English and other loanwords (cf. chapter word origin ). Article 1 of
9701-400: The other. In general, the alphabets are used interchangeably; except in the legal sphere, where Cyrillic is required, there is no context where one alphabet or another predominates. Although Serbian language authorities have recognized the official status of both scripts in contemporary Standard Serbian for more than half of a century now, due to historical reasons, the Cyrillic script was made
9810-643: The oxidative roasting of chromite ore with sodium carbonate . The change in equilibrium is visible by a change from yellow (chromate) to orange (dichromate), such as when an acid is added to a neutral solution of potassium chromate . At yet lower pH values, further condensation to more complex oxyanions of chromium is possible. Both the chromate and dichromate anions are strong oxidizing reagents at low pH: They are, however, only moderately oxidizing at high pH: Chromium(VI) compounds in solution can be detected by adding an acidic hydrogen peroxide solution. The unstable dark blue chromium(VI) peroxide (CrO 5 )
9919-446: The oxide in a charcoal oven, for which he is credited as the one who truly discovered the element. Vauquelin was also able to detect traces of chromium in precious gemstones , such as ruby and emerald . During the nineteenth century, chromium was primarily used not only as a component of paints, but in tanning salts as well. For quite some time, the crocoite found in Russia was the main source for such tanning materials. In 1827,
10028-456: The pale green [CrCl(H 2 O) 5 ]Cl 2 and violet [Cr(H 2 O) 6 ]Cl 3 . If anhydrous violet chromium(III) chloride is dissolved in water, the violet solution turns green after some time as the chloride in the inner coordination sphere is replaced by water. This kind of reaction is also observed with solutions of chrome alum and other water-soluble chromium(III) salts. A tetrahedral coordination of chromium(III) has been reported for
10137-415: The principal ions at this oxidation state. They exist at an equilibrium, determined by pH: Chromium(VI) oxyhalides are known also and include chromyl fluoride (CrO 2 F 2 ) and chromyl chloride ( CrO 2 Cl 2 ). However, despite several erroneous claims, chromium hexafluoride (as well as all higher hexahalides) remains unknown, as of 2020. Sodium chromate is produced industrially by
10246-423: The production of pure chromium, the iron must be separated from the chromium in a two step roasting and leaching process. The chromite ore is heated with a mixture of calcium carbonate and sodium carbonate in the presence of air. The chromium is oxidized to the hexavalent form, while the iron forms the stable Fe 2 O 3 . The subsequent leaching at higher elevated temperatures dissolves the chromates and leaves
10355-429: The reduction of chromium(VI) by cytochrome c7 . The Cr ion has a similar radius (63 pm ) to Al (radius 50 pm), and they can replace each other in some compounds, such as in chrome alum and alum . Chromium(III) tends to form octahedral complexes. Commercially available chromium(III) chloride hydrate is the dark green complex [CrCl 2 (H 2 O) 4 ]Cl. Closely related compounds are
10464-558: The region, some of the largest in Serbia (Niš, Leskovac, Vranje). Secondary centers are Aleksinac, Vlasotince and Preševo. Along with the Great Morava Valley, its natural continuation, the South Morava Valley is an important European transportation route and Niš is a major crossroads. It makes a section of the Belgrade- Skopje - Thessaloniki route, that is, of the European route E75 (which connects Norway and Greece ), with
10573-604: The rest in Central Serbia. In wider sense, the South Morava Valley is identified with southern Serbia in general and covers the entire watershed of the South Morava (15,469 km). Sub-regions which partially make up the South Morava Valley include: The South Morava Valley had a population of 680,176 inhabitants by the official 2018 estimate by the State Statistical Office, with an average population density of 217 inhabitants per square kilometer, but
10682-428: The rest of about 18% of the world production. The two main products of chromium ore refining are ferrochromium and metallic chromium. For those products the ore smelter process differs considerably. For the production of ferrochromium, the chromite ore (FeCr 2 O 4 ) is reduced in large scale in electric arc furnace or in smaller smelters with either aluminium or silicon in an aluminothermic reaction . For
10791-408: The rivers of Skrapež , Đetinja (headwaters of West Morava) and Rasina (a tributary, near the confluence with South Morava). It is generally bounded by the mountains of Tara , Zlatibor , Jelica , Goč , Suvobor , Maljen , Kotlenik and Gledić , that is, by the large geographical regions of Šumadija and Stari Vlah . The West Morava Valley is a composite valley, which means it consists of
10900-600: The same site as Lehmann and found a red lead mineral that was discovered to possess useful properties as a pigment in paints . After Pallas, the use of Siberian red lead as a paint pigment began to develop rapidly throughout the region. Crocoite would be the principal source of chromium in pigments until the discovery of chromite many years later. In 1794, Louis Nicolas Vauquelin received samples of crocoite ore . He produced chromium trioxide (CrO 3 ) by mixing crocoite with hydrochloric acid . In 1797, Vauquelin discovered that he could isolate metallic chromium by heating
11009-442: The scale. Above 950 °C volatile chromium trioxide CrO 3 forms from the chromia scale, limiting the scale thickness and oxidation protection. Chromium, unlike iron and nickel, does not suffer from hydrogen embrittlement . However, it does suffer from nitrogen embrittlement , reacting with nitrogen from air and forming brittle nitrides at the high temperatures necessary to work the metal parts. Naturally occurring chromium
11118-413: The second conditional (without use in the spoken language—it should be used for impossible conditional clauses). Serbian has active and passive voice . As for the non-finite verb forms, Serbian has one infinitive , two adjectival participles (the active and the passive), and two adverbial participles (the present and the past). Most Serbian words are of native Slavic lexical stock, tracing back to
11227-433: The second future tense or the future exact, which is considered a tense of the conditional mood by some contemporary linguists), and one present tense . These are the tenses of the indicative mood. Apart from the indicative mood, there is also the imperative mood . The conditional mood has two more tenses: the first conditional (commonly used in conditional clauses, both for possible and impossible conditional clauses) and
11336-414: The solution. During anodization, an oxide layer is formed on the aluminium. The use of chromic acid, instead of the normally used sulfuric acid, leads to a slight difference of these oxide layers. The high toxicity of Cr(VI) compounds, used in the established chromium electroplating process, and the strengthening of safety and environmental regulations demand a search for substitutes for chromium, or at least
11445-466: The spoken language. In the second half of the 18th century, the new language appeared, called Slavonic-Serbian . This artificial idiom superseded the works of poets and historians like Gavrilo Stefanović Venclović , who wrote in essentially modern Serbian in the 1720s. These vernacular compositions have remained cloistered from the general public and received due attention only with the advent of modern literary historians and writers like Milorad Pavić . In
11554-422: The strong increase in corrosion resistance made chromium an important alloying material for steel. High-speed tool steels contain 3–5% chromium. Stainless steel , the primary corrosion-resistant metal alloy, is formed when chromium is introduced to iron in concentrations above 11%. For stainless steel's formation, ferrochromium is added to the molten iron. Also, nickel-based alloys have increased strength due to
11663-491: The trihalides ( CrX 3 ) with the corresponding halogen at elevated temperatures. Such compounds are susceptible to disproportionation reactions and are not stable in water. Organic compounds containing Cr(IV) state such as chromium tetra t -butoxide are also known. Most chromium(I) compounds are obtained solely by oxidation of electron-rich, octahedral chromium(0) complexes. Other chromium(I) complexes contain cyclopentadienyl ligands. As verified by X-ray diffraction ,
11772-571: Was designed by the Croatian linguist Ljudevit Gaj in the 1830s based on the Czech system with a one-to-one grapheme-phoneme correlation between the Cyrillic and Latin orthographies, resulting in a parallel system. Serbian is a standardized variety of Serbo-Croatian , a Slavic language ( Indo-European ), of the South Slavic subgroup. Other standardized forms of Serbo-Croatian are Bosnian , Croatian , and Montenegrin . "An examination of all
11881-452: Was produced in 2013, and converted into 7.5 Mt of ferrochromium. According to John F. Papp, writing for the USGS, "Ferrochromium is the leading end use of chromite ore, [and] stainless steel is the leading end use of ferrochromium." The largest producers of chromium ore in 2013 have been South Africa (48%), Kazakhstan (13%), Turkey (11%), and India (10%), with several other countries producing
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