Osmium (Os)
Hard blue-white metallic transition element. Found with platinum and used in some alloys with platinum and iridium.
| Atomic Number | 76 |
|---|---|
| Atomic Weight | 190.23 |
| Mass Number | 192 |
| Group | 8 |
|---|---|
| Period | 6 |
| Block | d |
| Protons | 76 p+ |
|---|---|
| Neutrons | 116 n0 |
| Electrons | 76 e- |
Properties
| Atomic Radius | 130 pm
|
|---|---|
| Atomic Volume | 8.43 cm³/mol
|
| Covalent Radius | 129 pm
|
| Metallic Radius | 126 pm
|
| Ionic Radius | 63 pm
|
| Crystal Radius | 77 pm
|
| Van der Waals radius |
216 pm
|
| Density | 22.5872 g/cm³
|
| Boiling Point | 5,300 K
|
| Melting Point | 3,327 K
|
| Electrons per shell | 2, 8, 18, 32, 14, 2 |
| Electronegativity |
2.2
|
| Electrophilicity | 1.5497236992589 eV/particle
|
| Proton Affinity | |
| Electron Affinity | 1.1 eV/particle
|
| Ionization Potential | 8.43823 eV/particle
|
| Heat of Vaporization | 738 kJ/mol
|
| Heat of Fusion | 31.7 kJ/mol
|
| Heat of Formation | 787 kJ/mol
|
| Molar Heat Capacity | 24.7 J/(mol K)
|
| Specific Heat Capacity | 0.13 J/(g⋅K)
|
| Thermal Conductivity | |
| Gas Basicity | |
| Dipole Polarizability | 57 a₀
|
| C6 Dispersion Coefficient | |
| Oxidation States | -2, 1, 2, 3, 4, 5, 6, 7, 8 |
| Color | Slate Gray
|
| Crystal Structure | Simple Hexagonal (HEX) |
| Lattice Constant | 2.74 Å
|
| Bulk Modulus | |
| Electrical Resistivity | |
| Electron Configuration | [Xe] 4f14 5d6 6s2 |
| Magnetic Ordering | |
| Magnetic Susceptibility | |
| Phase | Solid |
| Poisson Ratio | |
| Shear Modulus | |
| Young's Modulus | |
| Allotropes | |
| Alternate Names | |
| Adiabatic Index | |
| Appearance | |
| Electric Conductivity | |
| Critical Pressure | |
| Critical Temperature | |
| Curie Point | |
| Electrical | |
| Hardness | |
| Magnetic Susceptibility | |
| Magnetic | |
| Neel Point | |
| Neutron Cross Section | |
| Neutron Mass Absorption | |
| Gas Phase | |
| Quantum Numbers | |
| Refractive Index | |
| Space Group | |
| Speed of Sound | |
| Superconducting Point | |
| Thermal Expansion | |
| Valence Electrons | |
| Classification | |
| Category | Transition metals, Transition metals |
| CAS Group | VIIIA |
| IUPAC Group | VIII |
| Glawe Number | 60 |
| Mendeleev Number | 61 |
| Pettifor Number | 62 |
| Geochemical Class | noble metal |
| Goldschmidt Class | siderophile |
| Radioactivity | |
| Radioactive | No |
| Decay Mode | |
| Half-Life | |
| Lifetime | |
| Abundance | |
| Abundance in Earth's crust | 0.0015 mg/kg
|
| Abundance in Oceans | |
| Abundance in Human Body | |
| Abundance in Meteor | |
| Abundance in Sun | |
| Abundance in Universe | 3×10-7% |
Isotopes of Osmium
Stable Isotopes
184Os 186Os 187Os 188Os 189Os 190Os 192Os
Unstable Isotopes
162Os 163Os 164Os 165Os 166Os 167Os 168Os 169Os 170Os 171Os 172Os 173Os 174Os 175Os 176Os 177Os 178Os 179Os 180Os 181Os 182Os 183Os 185Os 191Os 193Os 194Os 195Os 196Os
History
Osmium was discovered in 1803 by English chemist Smithson Tennant in London. Chemists who studied platinum dissolved it in aqua regia to create soluble salts and observed a small amount of a dark, insoluble residue. Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal. From the Greek word osme, meaning smell
| Discoverers | Smithson Tenant |
|---|---|
| Discovery Location | England |
| Discovery Year | 1804 |
| Name Origin | Greek: osmê (odor). |
Even low concentrations in air can cause lung congestion, skin damage, or eye damage
Osmium is the least abundant stable element in the Earth's crust
Uses
Osmium is used alloyed with other metals in the platinum group to produce very hard alloys. Osmium alloys are used in the tips of fountain pens, instrument pivots, and electrical contacts Osmium tetroxide has been used in fingerprint detection and in staining fatty tissue for optical and electron microscopy. Used to tip gold pen points, instrument pivots, to make electric light filaments. Used for high temp. alloys and pressure bearings. Very hard and resists corrosion better than any other.
Sources
Obtained from the same ores as platinum.