Rh redirects here. Rh redirects here For other uses see Rh (disambiguation Rhodium (ˈroʊdiəm is a Chemical element with the symbol For other uses, see rh (disambiguation)

45 ruthenium ← rhodium → palladium Co ↑ Rh ↓ Ir Periodic Table - Extended Periodic Table
General
Name, Symbol, Number	rhodium, Rh, 45
Chemical series	transition metals
Group, Period, Block	9, 5, d
Appearance	silvery white metallic
Standard atomic weight	102.90550(2)  g·mol−1
Electron configuration	[Kr] 4d8 5s1
Electrons per shell	2, 8, 18, 16, 1
Physical properties
Phase	solid
Density (near r.t.)	12. Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Cobalt (ˈkoʊbɒlt is a hard lustrous silver-grey Metal, a Chemical element with symbol Co. Iridium (ɪˈrɪdiəm is a Chemical element that has the symbol Ir and Atomic number 77 This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In Chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings It commonly refers to any element in In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic Applications Alloys with other metals primarially to add corrosion and wear resistance Industrial Catalysts Superalloys Electrical A period 5 element is one of the Chemical elements in the fifth row (or period) of the periodic table of the elements. The d-block of the periodic table of the elements consists of those Periodic table groups that contain elements in which in the atomic ground state the highest-energy The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass To help compare different orders of magnitude, the following list describes various Mass levels between 10&minus36&thinsp kg and 1053&thinspkg In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other Krypton (ˈkrɪptən or /ˈkrɪptɒn/ from kryptos "hidden" is a Chemical element with the symbol Kr and Atomic number 36 The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 41  g·cm−3
Liquid density at m.p.	10. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 7  g·cm−3
Melting point	2237 K (1964 °C, 3567 °F)
Boiling point	3968 K (3695 °C, 6683 °F)
Heat of fusion	26. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 59  kJ·mol−1
Heat of vaporization	494  kJ·mol−1
Specific heat capacity	(25 °C) 24. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 98  J·mol−1·K−1
Vapor pressure P(Pa) 1 10 100 1 k 10 k 100 k at T(K) 2288 2496 2749 3063 3405 3997
Atomic properties
Crystal structure	cubic face centered
Oxidation states	4, 3, 2, 1[1] (amphoteric oxide)
Electronegativity	2. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 28 (Pauling scale)
Ionization energies	1st: 719. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron 7 kJ/mol
	2nd: 1740 kJ/mol
	3rd: 2997 kJ/mol
Atomic radius	135  pm
Atomic radius (calc. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances A picometre ( American spelling: picometer, symbol pm) is a unit of Length in the Metric system, equal to one trillionth )	173  pm
Covalent radius	135  pm
Miscellaneous
Magnetic ordering	no data
Electrical resistivity	(0 °C) 43. The covalent radius, r cov is a measure of the size of Atom which forms part of a Covalent bond. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. 3 nΩ·m
Thermal conductivity	(300 K) 150  W·m−1·K−1
Thermal expansion	(25 °C) 8. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes 2  µm·m−1·K−1
Speed of sound (thin rod)	(20 °C) 4700 m/s
Young's modulus	380  GPa
Shear modulus	150  GPa
Bulk modulus	275  GPa
Poisson ratio	0. Sound is a vibration that travels through an elastic medium as a Wave. In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material In Materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of Shear Poisson's ratio ( ν) named after Simeon Poisson, is the ratio of the relative contraction strain, or transverse strain (normal to 26
Mohs hardness	6. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 0
Vickers hardness	1246  MPa
Brinell hardness	1100  MPa
CAS registry number	7440-16-6
Selected isotopes
Main article: Isotopes of rhodium iso NA half-life DM DE (MeV) DP 99Rh syn 16. The Vickers hardness test was developed in 1924 by Smith and Sandland as an alternative method to measure the Hardness of materials The Brinell scale characterizes the indentation Hardness of materials through the scale of penetration of an indenter loaded on a material test-piece CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Naturally occurring Rhodium ( Rh) is composed of only one Isotope, 103Rh Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 1 d ε - 99Ru γ 0. A day (symbol d is a unit of Time equivalent to 24 Hours and the duration of a single Rotation of planet Earth with respect to the Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 089, 0. 353, 0. 528 - 101mRh syn 4.34 d ε - 101Ru IT 0. A nuclear isomer is a Metastable state of an Atomic nucleus caused by the excitation of one or more of its Nucleons A nuclear isomer occupies A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in To help compare Orders of magnitude of different Times this page lists times between 105 seconds and 106 seconds (approximately 27 Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Internal conversion is a Radioactive decay process where an excited nucleus interacts with an Electron in one of the lower electron shells causing the 157 101Rh γ 0. Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 306, 0. 545 - 101Rh syn 3.3 y ε - 101Ru γ 0. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in To help compare Orders of magnitude of different times this page lists times between 3 Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 127, 0. 198, 0. 325 - 102mRh syn 2. A nuclear isomer is a Metastable state of an Atomic nucleus caused by the excitation of one or more of its Nucleons A nuclear isomer occupies A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 9 y ε - 102Ru γ 0. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 475, 0. 631, 0. 697, 1. 046 - 102Rh syn 207 d ε - 102Ru β+ 0. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in To help compare Orders of magnitude of different times this page lists times between 116 Days and 1157 days or 3 Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Positron emission is a type of Beta decay, sometimes referred to as " beta plus " (&beta+ 826, 1. 301 102Ru β- 1. Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 151 102Pd γ 0. Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 475, 0. 628 - 103Rh 100% 103Rh is stable with 58 neutrons 105Rh syn 35. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 36 h β- 0. The hour (symbol h) is a unit of Time. It is not an SI unit but is accepted for use with the SI In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 247, 0. 260, 0. 566 105Pd γ 0. Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 306, 0. 318 -
References

Rhodium (pronounced /ˈroʊdiəm/) is a chemical element with the symbol Rh and atomic number 45. Recommended values for many properties of the elements together with various references are collected on these data pages A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton A rare silvery-white hard transition metal and a member of the platinum group, rhodium is found in platinum ores and is used in alloys with platinum and as a catalyst. In Chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings It commonly refers to any element in The platinum group (alternatively the platinum group metals or platinum metals) is a collective name sometimes used for six Metallic elements An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst It is usually the most expensive precious metal^[2], though it is sometimes surpassed by rhenium, depending on the market. Precious Metal is the eighteenth episode in the of the popular American Crime drama, which is set in Las Vegas, Nevada. Rhenium (ˈriːniəm is a Chemical element with the symbol Re and Atomic number 75

Notable characteristics

Rhodium is a hard silvery white and durable metal that has a high reflectance. In photometry and Heat transfer, reflectivity is the fraction of incident radiation reflected by a surface Rhodium metal does not normally form an oxide, even when heated. An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element Oxygen is absorbed from the atmosphere at the melting point of rhodium, but on solidification the oxygen is released. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the An atmosphere (from Greek ατμός - atmos, " Vapor " + σφαίρα - sphaira, " Sphere " The melting point of a solid is the temperature range at which it changes state from solid to Liquid. ^[3] Rhodium has both a higher melting point and lower density than platinum. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 It is not attacked by acids: it is completely insoluble in nitric acid and dissolves slightly in aqua regia. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Nitric acid ( H[[nitrate NO3]] also known as Aqua fortis and spirit of nitre, is a highly corrosive and Aqua regia ( Latin for royal water) is a highly corrosive fuming yellow or red solution A complete dissolution of rhodium in powder form is only obtained in sulfuric acid. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid.

Applications

The primary use of this element is as an alloying agent for hardening platinum and palladium. Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the These alloys are used in furnace windings, bushings for glass fiber production, thermocouple elements, electrodes for aircraft spark plugs, and laboratory crucibles. In Electrical engineering and industry thermocouples are a widely used type of temperature sensor and can also be used as a means to convert thermal Potential An electrode is an Electrical conductor used to make contact with a nonmetallic part of a circuit (e A spark plug (also very rarely nowadays in British English: a sparking plug) is an electrical device that fits into the Cylinder Other uses include:

• It is used as an electrical contact material due to its low electrical resistance, low and stable contact resistance, and its high corrosion resistance. A switch is a mechanical device used to connect and disconnect an electric Circuit at will Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is The term contact resistance refers to the contribution to the total resistance of a material which comes from the electrical leads and connections as opposed to the intrinsic Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings
• Plated rhodium, made by electroplating or evaporation, is extremely hard and is used for optical instruments. Electroplating is the process of using electrical current to reduce Cations of a desired material from a solution and coat a conductive object
• This metal finds use in jewelry and for decorations. Jewellery (also spelled jewelry, see spelling differences) is a personal Ornament, such as a necklace ring or bracelet made from Gemstones It is electroplated on white gold and platinum to give it a reflective white surface. White gold is an Alloy of Gold and at least one White metal, usually Nickel or Palladium. This is known as rhodium flashing in the jewelry business. It also may be used in coating sterling silver in order to strengthen the metal from tarnish, as a result from the copper compound found in sterling silver. Sterling silver is an Alloy of Silver containing 925% pure silver and 7 Sterling silver is an Alloy of Silver containing 925% pure silver and 7
• It is also a highly useful catalyst in a number of industrial processes (notably it is used in the catalytic system of automobile catalytic converters and for catalytic carbonylation of methanol to produce acetic acid by the Monsanto process). Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst A catalytic converter (colloquially "cat" or "catcon" is a device used to reduce the toxicity of emissions from an Internal combustion engine. Acetic acid, also known as ethanoic acid, is an organic chemical compound, giving Vinegar its sour taste The Monsanto process is an important method for the manufacture of Acetic acid. It is used to catalyse addition of hydrosilanes to a double bond, a process important in manufacture of certain silicone rubbers.
• The complex of a rhodium ion with BINAP gives a widely used chiral catalyst for chiral synthesis, as in the synthesis of menthol. BINAP is an Acronym for the Organophosphorus compound 22'-bis(diphenylphosphino-11'-binaphthyl Asymmetric synthesis, also called chiral synthesis, enantioselective synthesis or stereoselective synthesis, is Organic synthesis which Menthol is an Organic compound made synthetically or obtained from Peppermint or other mint oils
• It is also used as a filter in mammography systems because of the characteristic x-rays it produces. Mammography is the process of using low-dose X-rays (usually around 0
• It is also used in high quality pen surfaces due to its high-resistance characteristics. These pens include Graf von Faber-Castell which is rather less famous than Montblanc, but produces very limited pens.

History

Rhodium (Greek rhodon meaning "rose") was discovered in 1803 by William Hyde Wollaston,^[4] soon after his discovery of palladium. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly 1803 ( MDCCCIII) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a William Hyde Wollaston FRS ( August 6, 1766 &ndash December 22, 1828) was an English Chemist and physicist Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the He made this discovery in England using crude platinum ore that he presumably obtained from South America. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a

His procedure involved dissolving the ore in aqua regia, neutralizing the acid with sodium hydroxide (NaOH). Aqua regia ( Latin for royal water) is a highly corrosive fuming yellow or red solution Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 He then precipitated the platinum by adding ammonium chloride, NH₄Cl, as ammonium chloroplatinate. Ammonium chloride ( N[[Hydrogen H]]4 Cl) (also Sal Ammoniac, salmiac, nushadir salt, zalmiak, sal armagnac Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and The element palladium was removed as palladium cyanide after treating the solution with mercuric cyanide. Mercury(II cyanide, also known as mercuric cyanide is a salt of mercury. The material that remained was a red rhodium(III) chloride (hence the name): rhodium metal was isolated via reduction with hydrogen gas. Rhodium(III chloride usually refers to hydrated rhodium trichloride, a molecular compound with the formula RhCl3(H2O3 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1

Occurrence

Normal mining

The industrial extraction of rhodium is complex as the metal occurs in ores mixed with other metals such as palladium, silver, platinum, and gold. Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 It is found in platinum ores and obtained free as a white inert metal which is very difficult to fuse. Principal sources of this element are located in South Africa, in river sands of the Ural Mountains, in North and South America and also in the copper-nickel sulfide mining area of the Sudbury, Ontario region. Riphean redirects here For the time period see Riphean stage The Ural Mountains (Ура́льские го́ры Uralskiye Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Millerite is a Nickel Sulfide Mineral, NiS It is brassy in colour and has an acicular habit often forming radiating masses and furry aggregates Greater Sudbury (2006 Census population 157857 is a city in Northern Ontario, Canada. Although the quantity at Sudbury is very small, the large amount of nickel ore processed makes rhodium recovery cost effective. The main exporter of rhodium is South Africa (>80%) followed by Russia. The annual world production of this element is only about 25 tons and there are very few rhodium minerals. Units of mass There are three similar units of Mass called the ton: Long ton (simply ton in countries such as the United A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific As of October 2007, rhodium cost approximately eight times more than gold, 450 times more than silver, and 27,250 times more than copper by weight. Rhodium's typical historical price is about $1,000/troy oz,^[5] but in recent years it has increased to about $9500/troy oz. ^[6]

As a fission product

It is also possible to extract rhodium from used nuclear fuel, which contains rhodium (1 kg of the fission products of ²³⁵U contain 13. Spent nuclear fuel, occasionally called used nuclear fuel, is Nuclear fuel that has been irradiated in a Nuclear reactor (usually at a Nuclear power Fission products are the atomic fragments left after a large nucleus fissions. 3 grams of ¹⁰³Rh). So as a typical used fuel is 3% fission products by weight it will contain about 400 grams of rhodium per ton of used fuel. The longest lived radioisotope of rhodium is ^102mRh which has a half life of 2. 9 years, while the ground state (¹⁰²Rh)has a half life of 207 days.

Each kilo of fission rhodium will contain 6. 62 ng of ¹⁰²Rh and 3. 68 ng of ^102mRh. As ¹⁰²Rh decays by beta decay to either ¹⁰²Ru (80%) (some positron emission will occur) or ¹⁰²Pd (20%) (some gamma ray photons with about 500 keV are generated) and the excited state decays by beta decay (electron capture) to ¹⁰²Ru (some gamma ray photons with about 1 MeV are generated). In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted Positron emission is a type of Beta decay, sometimes referred to as " beta plus " (&beta+ Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions If the fission occurs in an instant then 13. 3 grams of rhodium will contain 67. 1 MBq (1. 81 mCi) of ¹⁰²Rh and 10. 8 MBq (291 μCi) of ^102mRh. As it is normal to allow used nuclear fuel to stand for about five years before reprocessing, much of this activity will decay away leaving 4. 7 MBq of ¹⁰²Rh and 5. 0 MBq of ^102mRh. If the rhodium metal was then left for 20 years after fission, then the 13. 3 grams of rhodium metal would contain 1. 3 kBq of ¹⁰²Rh and 500 kBq of ^102mRh. At first glance the rhodium might be adding to the resource value of reprocessed fission waste, but the cost of the separation of the rhodium from the other metals needs to be considered.

The radioactivity in MBq per gram of each of the platinum group metals which are formed by the fission of uranium, ruthenium is the most radioactive. Palladium has an almost constant activity due to the very long lived ¹⁰⁷Pd, while rhodium is the least radioactive

Isotopes

Main article: isotopes of rhodium

Naturally occurring rhodium is composed of only one isotope, ¹⁰³Rh. Palladium -107 is the second longest lived ( Halflife of 65 million years and least radioactive ( Decay energy only 33 KeV, Specific activity Naturally occurring Rhodium ( Rh) is composed of only one Isotope, 103Rh Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides The most stable radioisotopes are ¹⁰¹Rh with a half-life of 3. A radionuclide is an Atom with an unstable nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created Half-Life (computer-game page here It's already listed in the disambiguation page 3 years, ¹⁰²Rh with a half-life of 207 days, ^102mRh with a half-life of 2. Half-Life (computer-game page here It's already listed in the disambiguation page Half-Life (computer-game page here It's already listed in the disambiguation page 9 years, and ⁹⁹Rh with a half-life of 16. 1 days. Twenty other radioisotopes have been characterized with atomic weights ranging from 92. The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass 926 u (⁹³Rh) to 116. The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express 925 u (¹¹⁷Rh). Most of these have half-lifes that are less than an hour except ¹⁰⁰Rh (half-life: 20. 8 hours) and ¹⁰⁵Rh (half-life: 35. 36 hours). There are also numerous meta states with the most stable being ^102mRh (0. A nuclear isomer is a Metastable state of an Atomic nucleus caused by the excitation of one or more of its Nucleons A nuclear isomer occupies 141 MeV) with a half-life of about 207 days and ^101mRh (0. 157 MeV) with a half-life of 4. 34 days. See isotopes of rhodium. Naturally occurring Rhodium ( Rh) is composed of only one Isotope, 103Rh

The primary decay mode before the only stable isotope, ¹⁰³Rh, is electron capture and the primary mode after is beta emission. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted The primary decay product before ¹⁰³Rh is ruthenium and the primary product after is palladium. In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide Ruthenium (ruːˈθiːniəm is a Chemical element that has the symbol Ru and Atomic number 44 Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the

Precautions

Rhodium metal is, as a noble metal, inert. However, when rhodium is chemically bound, it is reactive. Rhodium compounds are not often encountered by most people and should be considered to be toxic and possibly carcinogenic. Toxicity is the degree to which a substance is able to damage an exposed organism The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation Lethal intake (LD50) for rats is 12. 6 mg/kg of rhodium chloride (RhCl₃). Rhodium compounds can strongly stain human skin. The element plays no biological role in humans. If used in elemental form rather than as compounds, the metal is harmless.

Symbolic uses

Rhodium has been used for honours, or to symbolize wealth, when more commonly used metals such as silver, gold, or platinum are deemed insufficient. In 1979 the Guinness Book of World Records gave Paul McCartney a rhodium-plated disc for being history's all-time best-selling songwriter and recording artist. Guinness World Records, known until 2000 as The Guinness Book of Records (and in previous U Sir James Paul McCartney, MBE (born 18 June 1942 is an English rock Singer, Bass guitarist songwriter Composer, Guinness has also noted items such as the world's "Most Expensive Pen" or "Most Expensive Board Game" as containing rhodium.

See also

• Rhodium compounds

References

1. ^ Rhodium: rhodium(I) fluoride compound data. OpenMOPAC. net. Retrieved on 2007-12-10. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1041 - Empress Zoe of Byzantium elevates her adoptive son to the throne of the Eastern Roman Empire as Michael V
2. ^ Precious Metal Prices Index
3. ^ Emsley, John (2001). Nature's Building Blocks, (Hardcover, First Edition), Oxford University Press, page 363. ISBN 0198503407.  
4. ^ WebElements - The History of Rhodium
5. ^ http://periodic.lanl.gov/elements/45.html
6. ^ KITCO Rhodium Price Charts

External links

• WebElements.com – Rhodium
• Current Rhodium price
• Rhodium Technical and Safety Data
• Los Alamos National Laboratory – Rhodium

Rhodium foil and wire