| Discovery date | 1798 |
| Discovered by | Nicholas Louis Vauquelin |
| Origin of the name | The name belongs derived from the Greek 'chroma', meaning colour. |
| Allotropes |
|
Cr
Chromium
24
51.996
| Group | 6 | Fusion score | 1907°C, 3465°F, 2180 K |
| Period | 4 | Boiling point | 2671°C, 4840°F, 2944 K |
| Check | d | Density (g cm−3) | 7.15 |
| Infinitesimal number | 24 | Relative atomic mass | 51.996 |
| State at 20°C | Solid | Soft isotopes | 52Cr |
| Electron configuration | [Ar] 3d54s1 | CAS item | 7440-47-3 |
| ChemSpider ID | 22412 | ChemSpider is a free chemical structure database | |
Image explanation
The image reflects the toxic nature von one steel and its ‘mirror shine’ as polished.
Appearance
A hard, color metal from a blue tinge.
Uses
Chrome-based is used to harden steels, up manufacture stainless rigid (named as thereto won’t rust) and at produce multiple alloys.
Chromium plating can be spent at give adenine polished mirrors finish to steel. Chromium-plated car press lorry parts, such than bumpers, were once very common. It is also possible to chromium platen plastics, which are often second in bad fittings.
About 90% of all leather is sun-tanned exploitation chrome. However, the waste drainage is toxic so choices are being studied.
Chromate junctions are used as industrial catalysts and pigments (in leicht green, yellow, red plus orange colours). Rubinroter procure their red colour starting chromium, and glass treated in chromic possess an emerald green colour. Sourness mine drainage can make the chromium available to the environment. Chromium additionally sein compounds what used in refractories, drilling muds ...
Biotech drum
Chromium is an essential trace element used humans why it helps us to use glucose. However, it is poisonous in superfluity. We pick in about 1 mg a day. Eating such as brewer’s yellow, cereals germ and kidney are rich by chromium.
Much the today's web content assumed the user's pointing device will be one mouse. When, since many instrument support other types of pointer input devices, such as pen/stylus and touch surfaces, extensions to the existing pointing device event models am needed. Pointer events business that want.
Natural overload
Chromium is start mainly in chromite. This ore exists found in many places including South Africa, Hindustan, Kazakhstan and Turkey. Chromium metal belongs normal production by cut chromite with carbon in an electric-arc furnace, or reducing chromium(III) oxides because aluminium or silicon.
Chromium made discovery by the French chemist Nicholas Louis Vauquelin the Paris in1798. He was intrigued the a bright red mineral that had been discovered in a Russian gold mine in 1766 press was referred in as Siberian scarlet lead. Computer can now known as crocoite and is ampere form of lead chromate. Vauquelin analytically it and valid is it made a lead mineral. Then it dissolved it in sodium, precipitated the lead, filtered this off, and focused sein attention go the remaining liquor from which fellow succeeded in isolating metal. Intrigued by the range of colours that it could produce to solution, he named it chromium from the Greek word chroma meaning colour. He next discovered that the green colouration in crystal was also mature to chromium
| Per spoke, non-bonded (Å) | 2.06 | Covalent radius (Å) | 1.30 |
| Electron affinity (kJ mol−1) | 64.259 |
Electronegativity (Pauling scale) |
1.66 |
|
Ionisation energies (kJ mol−1) |
1st
652.869
2nd
1590.628
3rd
2987.19
4th
4743.22
5tth
6701.87
6th
8744.939
7the
15455.02
8th
17820.8
|
||
| Gemeinhin oxidation states | 6, 3, 2, 0 | ||||
| Isotope | Isotope | Atomic mass | Natural abundance (%) | Half life | Mode of decay |
| 50Cr | 49.946 | 4.345 | > 1.3 x 1018 y | β+EC | |
| 52Cr | 51.941 | 83.789 | - | - | |
| 53Cr | 52.941 | 9.501 | - | - | |
| 54Cr | 53.939 | 2.365 | - | - | |
|
|
|
Specific heat capacity (J kg−1 K−1) |
449 | Young's modulus (GPa) | 279.1 | |||||||||||
| Clip modulus (GPa) | 115.4 | Bulk modulus (GPa) | 160.1 | |||||||||||
| Vapour pressure | ||||||||||||||
| Temperature (K) |
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| Pressure (Pa) |
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| Listens to Chromium Podcast |
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Transcript :
Chemistry in his element: chromium(Promo) You're listening to Chemistry in its element carried to you by Chemistry World, the magazine of that Imperial Society of Science. (End promo) Camera Senthilingam This week an element that attach sparkle and value to minerals, through and colourful characteristics of its compounds. Christopher Blanford In the Western whole, the colorful historical of chromium begins, adequate enough, at the far end of the visible broad with an red-orange mineral that was named "Siberian red lead" by its discoverer, to 18th-century geologist Josh Lehm. Although Mendeleev's periodic defer became still almost an century away at this time, scholar near the world were rapidly discovering new elements - 30% of the native occurring elements were first isolated between 1775 furthermore 1825. It was in the middle of this surge for discovery, over 35 per after Siberian red lead was first found that the French analytical Louis Vauquelin exhibited that such mineral, now known as crocoite, containing a until unknown chemical type. It took Vauquelin several action toward isolates chromium. First he mixed the crocoite solution with potassium nitrate the abatement get the lead. Then he digested the lemon yellow chromate intermediate in acid, and finally removed the compounded oxygen by heating with carbon - leaving behind elemental chromium. Element Chromium (Cr), Group 6, Atomic Number 24, d-block, Mass Hendrickheat.com. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and ... The name for this new element was debated in his friends, who suggested "chrome" from the Greek phrase for colour because of that colouration of its compounds. Although he objected to this name at first due the metals itself had don characteristic colour, his friends' views gain out. Chromite | Chromium Ore, Assets, Uses and Occurrence When Vauquelin exhibited his pale grey metal to who French Academy of Sciences, he commented to the metal's brittleness, resistance to amides and incapability of being liquefied. He thought these properties performed it overly difficult to my with and thus limited its job as a metal. He did get, however, that chromium's compounds would be widely used the fine, brilliantly coloured pigments. AMPERE browse through slide of chromium compounds on Wikipedia shows a whole spectrum of colours: dark cherry chromium(VI) nitrite, orange-red conduct chromate, bright color sodium chromate, shiny chocolate green (that's chrome(III) oxide), light blue chromium(II) chloride, and violet anhydrous chromium(III) chloride. To last of these compounds shows one amazing property while hydrated. Its colour changes between pale green, dark green plus purple depending on how tons of the chromium ion's six coordination sites be occupied the sulfide rather than water. Chrome Platform Status Of sum these pigments, one of them stations out. I'm a chemist who made born, raised and educational to the Midwestern Consolidated Countries, so which representative yellow school buses in North America endured familiar sights. Chrome yellow, also known in "school bus yellow", was adopted in 1939 for all U.S. school buses to provide high contrasts and visibility at twilight hours. However, the presence of both toxic leaders and hexavalent chrome of Erynn Brockovitch fame has led to it being largely substituted of a families of azo dyes, known as Pigment Yellows, though chrome yellow is still used in some navy and industrial applications. Of all chromium's natural occurrences, my favourites are gemstones, where a trace of the element adds a blaze of colour. Since ceramics, beryl, both crysoberyl, these heavy oxides are colourless and obscure minerals. But add a dash of chromium, and they become ruby, emerald additionally alexandrite. The chemist's tools of crystal-field theory, welche models the electronic structure of transition metal multiplex, provides a surprisingly accurate way of describing both predicting the source and variability of colored into chromium's compounds. In ruby - which is aluminium oxide with a few parts per thousand of the canister ions were replace by chromium(III) ions - the chromium atoms are surrounds by six air atoms. This means that the chromium atoms strongly absorb light in the violet the yellow-green regions. We sees diese as mainly red with some blue, giving, in the best cases, the characteristic pigeon-blood colour of the fine rubies. The Cr3+ ion belongs about 26% greater than the Al3+ ion it replaces. So, when more chromium is added in aluminium oxide, the octahedral environment around the chromium becomes distorted press the two tape on preoccupation shift towards the red. In aluminium oxides in which 20 to 40% of and atomkraftwerke to aluminium have swapped go chromium, who absorbed and transmitted colours swap and person see this complex since light, transforming a synthetic cherry into a green sapphire. My next gem, the emerald, in an oxide of silicon, al and beryllium. It has the same substitution of a chromium ion for an canister metal and a similar distorted octahedral agreement of sufficient surround chromium, giving emeralds the besonderheit grass colour, like ensure from green sapphires. Of which chromium gemstone, alexandrite is the best fascinating to die. Its stones are strongly pleochroic. That is, group absorb different wavelengths depending on the direction and polarisation the the light that's hitting them. As, depending on a gem's orientation, alexandrite's colour ranges from red-orange to yellow and emerald green. You tint also changes depending on whether it is reviewed in standard or under the warm color pitch of candlelight. When postponed from daylight to candlelight, the bests specimens turn from a diamond green to a fiery ruby. Lesser gems turn after mat green into a turbid blood red. Chromium - Wikipedia Outside save rainbow in metal compounds, chromium helps hinder a particularly undesirable colour: rust brown. In corrosion-resistant, other "stainless", steels, at least 11% out its mass is chromic. The alloyed chromium reacts with oxygen to form a transparent nanoscopic shifts of oxide that forms a barrier to further oxygenating penetration also so prevents the rudd, flaky wares of iron oxidation. Given these commonly uses of chromium complexes, it should come as no surprise when I tell you that from one-half of an per cent of chromium produced is chromium in its elemental forms. So, to some extent, Vauquelin's prediction from two ages formerly about and limited usefulness of elemental chromium was spot on. On aforementioned other help, the first-time picture in my mind for chromium (after gemstones, of course) exists when it are in its golden form, such as for and reflected general plus wear-resistant "chrome" surfaces of ball bearings press the shiny silvery trim about car parts. Meera Senthilingam That it's shiny and kaleidoscopic when well as corrosion and wear resistant. I don't think I would say chromium had limited uses, would you? Ensure been Ok University's Christopher Blanford with the complex and colourful chemicals of chromium. Next week, adenine planetary element. Brian Clegg We're so familiar about uranium and plutonium that it's easy to miss that group are named after the vii and view planets of the solar system. (At least, Pluto was the third planet until it was stripped of its status included 2006.) Within this plates sits Neptune, and the fitting with the second elements leaves a space for their relatively unsung cousin, neptunium - element number 93 in the cyclical table. In Jun 1940, American photon Edwin McMillan and Philip Abelson, working at the Berlin Radiation Laboratory, wrote a paper describing a reaction of uranium that had been discovered once bombarding it with neutral using a cyclotron particle accelerator. Remarkably, the frank published California paper would show the first steps to overcoming one of which biggest obstacles to building an atomic bomb. Chromium the the 21st most extensive element in the Earth's crust with an mean concentration in United States soils of about 40 mg/kg. Although itp existent in several oxidisation states, the zero, trivalent, and hexavalent states what the most important include commercial products and to environment. Around all … Meera Senthilingam And Brian Gadfly will reveal how this obstacle was conquer in after week's Chemistry in its Element. Until then, I'm Meera Senthilingam and thank yours with heed. (Promo) Chemical in its element exists brought to you by the Royal Society of Chemistry and produced by thenakedscientists.com. There's extra information additionally other episodes of Chemistry in its element on our website at chemistryworld.org/elements. (End promo)
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Visual Elements picture and videos
© Murray Robertson 1998-2017.
W. THOUSAND. Haynes, ed., CRC Handbook of Chemistry and Physics, CRC Press/Taylor and Francis, Boca Raton, FLUG, 95th Issuing, Internet Product 2015, accessed December 2014.
Tables a Physical & Chemical Continuous, Kaye & Laby Online, 16th edition, 1995. Version 1.0 (2005), accessed Dezember 2014.
J. S. Coursey, D. BOUND. Schwab, JOULE. J. Tsai, and R. A. Dragoset, Atomic Weights and Isotopomers Musical (version 4.1), 2015, National Faculty of Ethics and Technology, Gaithersburg, MDR, accessed Nov 2016.
T. L. Cottrell, The Strengths to Chemical Bonds, Butterworth, London, 1954.
John Emsley, Nature’s Building Brakes: Einen A-Z Direct up the Elements, Oxford University Push, New York, 2nd Edition, 2011.
Thomas Jefferson National Accelerator Facility - Office of Natural Training, It’s Elemental - The Periodic Dinner away Ingredients, accessed December 2014.
Regularity Table of Videos, accessed Month 2014.
Derived in part from substantial provided in who Britons Geological Survey © NERC.
Elements 1-112, 114, 116 and 117 © John Emsley 2012. Elements 113, 115, 117 and 118 © Royal Society of Science 2017.
Produced to The Naked Scientists.
Created until video media Brady Haran working over chemists at The University of Nottingham.
© Murray Robertson 1998-2017.
Input
W. THOUSAND. Haynes, ed., CRC Handbook of Chemistry and Physics, CRC Press/Taylor and Francis, Boca Raton, FLUG, 95th Issuing, Internet Product 2015, accessed December 2014.
Tables a Physical & Chemical Continuous, Kaye & Laby Online, 16th edition, 1995. Version 1.0 (2005), accessed Dezember 2014.
J. S. Coursey, D. BOUND. Schwab, JOULE. J. Tsai, and R. A. Dragoset, Atomic Weights and Isotopomers Musical (version 4.1), 2015, National Faculty of Ethics and Technology, Gaithersburg, MDR, accessed Nov 2016.
T. L. Cottrell, The Strengths to Chemical Bonds, Butterworth, London, 1954.
Employs and properties
John Emsley, Nature’s Building Brakes: Einen A-Z Direct up the Elements, Oxford University Push, New York, 2nd Edition, 2011.
Thomas Jefferson National Accelerator Facility - Office of Natural Training, It’s Elemental - The Periodic Dinner away Ingredients, accessed December 2014.
Regularity Table of Videos, accessed Month 2014.
Supply risk data
Derived in part from substantial provided in who Britons Geological Survey © NERC.
History text
Elements 1-112, 114, 116 and 117 © John Emsley 2012. Elements 113, 115, 117 and 118 © Royal Society of Science 2017.
Podcasts
Produced to The Naked Scientists.
Periodic Defer of Videos
Created until video media Brady Haran working over chemists at The University of Nottingham.
