76 - Osmium transition metal
Discovered by Smithson Tennant in 1803
- Atomic Radius (Å)
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.
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 |
190.23 u
Atomic Mass
1.9 Å
Atomic Radius
5285 K
Boiling Point
1.44 Å
Covalent Radius
22.59 g/cm³
Density
103.99
Electron Affinity
2.2
Electronegativity
8.44 eV
First Ionization Energy
3300.15 K
Melting Point
6
Number of Shells
76
Atomic Number
2, 8, 18, 32, 14, 2
Electron Shell Occupations