76 - Osmium transition metal
Discovered by Smithson Tennant in 1803
Osmium (from Greek osme (ὀσμή) meaning "smell") is a chemical element with symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with a density of 22.59 g/cm^3.
Periodic table
| Shell | Electrons | Orbitals |
|---|---|---|
| 1 | 2 | 2 in 1s |
| 2 | 8 | 2 in 2s + 6 in 2p |
| 3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
| 4 | 32 | 2 in 4s + 6 in 4p + 10 in 4d + 14 in 4f |
| 5 | 14 | 2 in 5s + 6 in 5p + 6 in 5d |
| 6 | 2 | 2 in 6s |
Electron shells
silvery, blue cast Appearance
190 u Atomic Mass
1.3 Å Atomic Radius
5.29k K Boiling Point
8 Group
4 Common Oxidation States
1.44 Å Covalent Radius
22.6 g/cm³ Density
104 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d6 Electron Configuration
[Xe] 4f14 5d6 6s2 Electron Configuration (semantic)
2.2 Electronegativity
76 Electrons
8.44 eV First Ionization Energy
840, 1600 kJ/mol Ionization Energies
3.3k K Melting Point
63 Mendeleev Number
24.7 J/(mol·K) Molar Heat
6 Number of Shells
114 Neutrons
76 Atomic Number
19 Number of Isotopes
-2, -1, 1, 2, 3, 4, 5, 6, 7, 8 Oxidation States
6 Period
Solid Phase
76 Protons
2, 8, 18, 32, 14, 2 Electron Shell Occupations
0.13 J/(g K) Specific Heat