SymbolPt
Latin namePlatinium
Atomic number78
Period6
Element categoryTransition elements
Relative atomic mass195.08
GroupVIII.B
Electronegativity
2.2
Oxidation numbers
2, 4, 6
Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d9 6s1
Density [g/cm3]
21.45
State
Solid
Melting point [°C]
1772
Boiling point [°C]
3827
Atomic radius [pm]
177
Covalent radius [pm]
128
Thermal conductivity [W m-1K-1]
71.6
Heat capacity [J K-1g-1]
0.13
Discovery
1735
Hardness [Mohs scale]
4.3
Vickers hardness [MPa]
549
Brinell hardness [MPa]
392
Young's modulus [GPa]
168
Electrical conductivity [S m-1]
9.4 · 106
Electrical resistivity [10-6Ω.m]
0.106
Shear modulus [GPa]
61
1.st ionization energy [eV]
9.0
2.nd ionization energy [eV]
18.563
Stable isotopes
6
Unstable isotopes
28