OSMIUM
| Academic Decathlon | Adult School | Baseball | Chemistry Topics |
| Chemical Compounds | Interests | Numbers | Periodic Table |
| Physics | Reference | Sports | Students |
|
|
OSMIUM |
|
| Do You Need Help in Chemistry? |
|
Introduction |
|
| Atomic Number: | 76 | Group: | 8 or VIII B | 76 | 190.23 |
| Average Atomic Mass: | 190.23 | Period: | 6 |
Os |
|
|
CAS Number: |
7440-04-02 | ||||
| Osmium | |||||
|
|
Classification |
|
| Metal | Nonmetal | Metalloid | ||
| Alkali Metal | Alkali Earth Metal | Transition Metal | Chalcogen | Halogen |
| Noble Gas | Lanthanoid | Actinoid |
Rare Earth Metal |
|
| Transuranium | No Stable Isotopes | |||
| Solid | Liquid | Gas |
Assumed Solid |
|
|
Description |
|
| Discovered in 1803 by Tennant in the residue left when crude platinum is dissolved by aqua regia. Osmium occurs in iridosmine and in platinum-bearing river sands of the Urals, North America, and South America. It is also found in the nickel-bearing ores of Sudbury, Ontario, region along with other platinum metals. While the quantity of platinum metals in these ores is very small, the large tonnages of nickel ores processed make commercial recovery possible. The metal is lustrous, bluish white, extremely hard, and brittle even at high temperatures. It has the highest melting point and the lowest vapor pressure of the platinum group. The metal is very difficult to fabricate, but the powder can be sintered in a hydrogen atmosphere at a temperature of 2000°C. The solid metal is not affected by air at room temperature, but the powdered or spongy metal slowly gives off osmium tetroxide, which is a powerful oxidizing agent and has a strong smell. The tetroxide is highly toxic, and boils at 130°C (760 mm). Concentrations in air as low as 10^–7 g/m^3 can cause lung congestion, skin damage, or eye damage. The tetroxide has been used to detect fingerprints and to stain fatty tissue for microscope slides. The metal is almost entirely used to produce very hard alloys, with other metals of the platinum group, for fountain pen tips, instrument pivots, phonograph needles, and electrical contacts. The price of 99.9% pure osmium powder — the form usually supplied commercially — is about $100/g, depending on quantity and supplier. Natural osmium contains seven isotopes, one of which, 186Os, is radioactive with a very long half-life. Thirty four other isotopes and isomers are known, all of which are radioactive.The measured densities of iridium and osmium seem to indicate that osmium is slightly more dense than iridium, so osmium has generally been credited with being the heaviest known element. Calculations of the density from the space lattice, which may be more reliable for these elements than actual measurements, however, give a density of 22.65 for iridium compared to 226.61 for osmium. At present, therefore, we know either iridium or osmium is the heaviest element, but the data do not allow selection between the two. 1 |
|
|
Physical Properties |
|
| Normal Melting Point: | 3033 °C = 3306.15 K = 5491.4 °F 2 | Normal Boiling Point: | 5012 °C = 5285.15 K = 9053.6 °F 2 |
| Sublimation Point: | Triple Point: | ||
| Critical Point: | |||
| Density: | 22.6 g/cm3 | Crystal Structure: | hexagonal |
| Atomic Radius: | 1.92 Ǻ = 192 pm | Covalent Radius: | 1.26 Ǻ = 126 pm |
| Ionic Radius: | 1 Ǻ = 100 pm | Atomic Volume: | 8.49 cm3/mol |
| Qualitative Solubility: | s molten alk, oxid flukes 3 | ||
| Note: Unless otherwise stated, solubility is for water at 25 degrees Celsius. | |||
|
|
Electron Configuration and Bonding |
|
| Predicted Electron Configuration: | [Xe] 6s2 4f14 5d6 |
Lewis Dot Diagram |
||||||
| Actual Electron Configuration: | [Xe] 6s2 4f14 5d6 |
x |
||||||
| Block: | d | Os |
x |
|||||
| Highest Occupied Energy Level: | 6 | |||||||
| Valence Electrons: | 2 | |||||||
| Quantum Numbers: | n = 5 | ℓ = 2 | mℓ = -2 | ms = -½ | ||||
| Please note that information in this section can be derived entirely from the periodic table. Although most people do not discuss valence electrons of the d-block and f-block elements, on this page the number of electrons in the highest energy level of the actual electron configuration was used to determine valence electrons. | ||||||||
| Electronegativity (Pauling): | 2.2 | Electropositivity (Pauling): | 1.8 | ||||
| Electron Affinity: | 1.10 eV = 106.13 kJ/mol = 25.37 kcal/mol | Oxidation States: | +4,6,8 | ||||
| Work Function:4 | 4.83 eV = 7.73766E-19 J | ||||||
| Ionization Potential 5 | eV | kJ/mol | Ionization Potential 5 | eV | kJ/mol | ||
| 1 | 8.4382 | 814.2 | |||||
| Note: Only the electronvolt values are given in the CRC Handbook, a conversion factor was used to find the kJ/mol value. | |||||||
|
|
Thermochemistry |
|
| Specific Heat: | 0.13 J/g°C = 0.031 cal/g°C | Thermal Conductivity: | 87.6 (W/m)/K, 27ºC | ||||
| Heat of Fusion: | 31.8 kJ/mol = 167.2 J/g | Heat of Vaporization: | 746 kJ/mol = 3921.6 J/g | ||||
| State of Matter | Enthalpy of Formation | Entropy of Formation | Gibbs Free Energy | ||||
| (kcal/mol) | (kJ/mol) | (cal/K) | (J/K) | (kcal/mol) | (kJ/mol) | ||
| (s) | 0 | 0 | 7.8 | 32.6352 | 0 | 0 | |
| (g) | 189 | 790.776 | 46.000 | 192.464 | 178 | 744.752 | |
|
|
Video |
|
| Video on osmium from the University of Nottingham's periodicvideos.com |
|
|
Isotopes |
|
| Nuclide | Mass | Half-Life | Nuclear Spin | Binding Energy (kJ/mol) |
| 162Os | 161.98443(54)# | 1.87(18) ms | 0+ | 119835082343.953 |
| 163Os | 162.98269(43)# | 5.5(6) ms | 7/2-# | 120614493289.222 |
| 164Os | 163.97804(22) | 21(1) ms | 0+ | 122292716606.51 |
| 165Os | 164.97676(22)# | 71(3) ms | (7/2-) | 123072127551.774 |
| 166Os | 165.972691(20) | 216(9) ms | 0+ | 123851538497.043 |
| 167Os | 166.97155(8) | 810(60) ms | 3/2-# | 124630949442.312 |
| 168Os | 167.967804(13) | 2.06(6) s | 0+ | 126309172759.598 |
| 169Os | 168.967019(27) | 3.40(9) s | 3/2-# | 127088583704.866 |
| 170Os | 169.963577(12) | 7.46(23) s | 0+ | 127867994650.133 |
| 171Os | 170.963185(20) | 8.3(2) s | (5/2-) | 128647405595.399 |
| 172Os | 171.960023(16) | 19.2(5) s | 0+ | 129426816540.668 |
| 173Os | 172.959808(16) | 22.4(9) s | (5/2-) | 131105039857.959 |
| 174Os | 173.957062(12) | 44(4) s | 0+ | 131884450803.225 |
| 175Os | 174.956946(15) | 1.4(1) min | (5/2-) | 132663861748.489 |
| 176Os | 175.95481(3) | 3.6(5) min | 0+ | 133443272693.758 |
| 177Os | 176.954965(17) | 3.0(2) min | 1/2- | 134222683639.027 |
| 178Os | 177.953251(18) | 5.0(4) min | 0+ | 135002094584.293 |
| 179Os | 178.953816(19) | 6.5(3) min | (1/2-) | 135781505529.56 |
| 180Os | 179.952379(22) | 21.5(4) min | 0+ | 136560916474.828 |
| 181Os | 180.95324(3) | 105(3) min | 1/2- | 137340327420.095 |
| 182Os | 181.952110(23) | 22.10(25) h | 0+ | 138119738365.364 |
| 183Os | 182.95313(5) | 13.0(5) h | 9/2+ | 138899149310.63 |
| 184Os | 183.9524891(14) | STABLE | 0+ | 139678560255.896 |
| 185Os | 184.9540423(14) | 93.6(5) d | 1/2- | 140457971201.163 |
| 186Os | 185.9538382(15) | 2.0(11)E+15 a | 0+ | 141237382146.432 |
| 187Os | 186.9557505(15) | STABLE | 1/2- | 142016793091.698 |
| 188Os | 187.9558382(15) | STABLE | 0+ | 142796204036.964 |
| 189Os | 188.9581475(16) | STABLE | 3/2- | 143575614982.233 |
| 190Os | 189.9584470(16) | STABLE | 0+ | 144355025927.5 |
| 191Os | 190.9609297(16) | 15.4(1) d | 9/2- | 144235624500.744 |
| 192Os | 191.9614807(27) | STABLE | 0+ | 145015035446.013 |
| 193Os | 192.9641516(27) | 30.11(1) h | 3/2- | 145794446391.279 |
| 194Os | 193.9651821(28) | 6.0(2) a | 0+ | 146573857336.545 |
| 195Os | 194.96813(54) | 6.5 min | 3/2-# | 147353268281.812 |
| 196Os | 195.96964(4) | 34.9(2) min | 0+ | 148132679227.078 |
| 197Os | 2.8(6) min | |||
| Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses. 6 | ||||
|
|
Reactions |
|
|
|
Abundance |
|
| Earth: | Crust: | 0.0015 mg/kg = 0.00000015% 7 |
| Earth: | Total: | 880 ppb 8 |
| Mercury: | Total: | 670 ppb 8 |
| Venus: | Total: | 920 ppb 8 |
|
|
Compounds |
|
|
|
Safety |
|
| Note: Not every link below has an entry for every element on the periodic table. Sites were selected based on those that had a large number of element and compound entries. |
| Scorecard's Pollution Information − not an MSDS, but it does provide basic information (among other things) on human heath hazards and industrial uses. |
| Although not truly an MSDS, Oxford University's Physical and Theoretical Chemistry Laboratory does provide some basic information. |
| Iowa State University |
| ESPI Metals |
|
|
Languages |
|
| Afrikaans: | Osmium | Albanian: | Osmium | Armenian: | Օսմիում | Arabic: | أوزميوم |
| Aromanian: | Osmiumu | Basque: | Osmioa | Bosnian: | Osmij | Breton: | Osmiom |
| Bulgarian: | Осмий | Byelorussian: | Осмій | Catalan: | Osmi | Chinese: | 锇 |
| Cornish: | Osmyum | Croatian: | Osmij | Czech: | Osmium | Danish: | Osmium |
| Dutch: | Osmium | Esperanto: | Osmio | Estonian: | Osmium | Faroese: | Osmium |
| Finnish: | Osmium | French: | Osmium | Friulian: | Osmi | Frisian: | Osmium |
| Galician: | Osmio | Georgian: | ოსმიუმი | German: | Osmium | Greek: | Οσμιο |
| Hebrew: | אוסמיום | Hungarian: | Ozmium | Icelandic: | Osmín | Irish Gaelic: | Oismiam |
| Italian: | Osmio | Japanese: | オスミウム | Kashubian: | Òsm | Kazakh: | Осмий |
| Korean: | 오스뮴 | Latvian: | Osmijs | Lithuanian: | Osmis | Luxembourgish: | Osmium |
| Macedonian: | Осмиум | Malay: | Osmium | Maltese: | Ozmjum | Manx Gaelic: | Osmium |
| Mokshan: | Осми | Mongolian: | Осми | Norwegian: | Osmium | Occitan: | Òsmi |
| Ossetian: | Осмий | Polish: | Osm | Portuguese: | Ósmio | Russian: | Осмий |
| Scottish Gaelic: | Oismiam | Serbian: | Осмиjум | Slovak: | Osmium | Spanish: | Osmio |
| Sudovian: | Usmijan | Swahili: | Osmi | Swedish: | Osmium | Tajik: | Osmi' |
| Thai: | ออสเมียม | Turkish: | Osmiyum | Ukranian: | Осмій | Uzbek: | Осмий |
| Vietnamese: | Osimi, Osmi | Welsh: | Osmiwm |
|
|
For More Information |
|
|
|
Sources |
|
| (1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4-21. |
| (2) - Lide, David R. CRC Handbook; CRC Press: Boca Raton, FL, 2002; p 4-132. |
| (3) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4-8 - 4-149. |
| (4) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1-132. |
| (5) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10-178 - 10-180. |
| (6) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009). |
| (7) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965. |
| (8) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14-17. |
|
|
OSMIUM |
|
| Site designed and maintained by Mr. Everett. |
| Last update: Thursday, August 12, 2010 |