Template:Infobox platinum

Platinum,  ₇₈Pt

General properties
Name, symbol	platinum, Pt
Appearance	silvery white
Pronunciation	/ˈplætᵻnəm/
Platinum in the periodic table
Pd ↑ Pt ↓ Ds iridium ← platinum → gold
Atomic number (Z)	78
Group, block	group 10, d-block
Period	period 6
Element category	transition metal
Standard atomic weight (±) (Ar)	195.084(9)
Electron configuration	[Xe] 4f14 5d9 6s1
per shell	2, 8, 18, 32, 17, 1
Physical properties
Phase	solid
Melting point	2041.4 K ​(1768.3 °C, ​3214.9 °F)
Boiling point	4098 K ​(3825 °C, ​6917 °F)
Density near r.t.	21.45 g/cm3
when liquid, at m.p.	19.77 g/cm3
Heat of fusion	22.17 kJ/mol
Heat of vaporization	510 kJ/mol
Molar heat capacity	25.86 J/(mol·K)
vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2330 (2550) 2815 3143 3556 4094
Atomic properties
Oxidation states	6, 5, 4, 3, 2, 1, −1, −2, −3 ​(a mildly basic oxide)
Electronegativity	Pauling scale: 2.28
Ionization energies	1st: 870 kJ/mol 2nd: 1791 kJ/mol
Atomic radius	empirical: 139 pm
Covalent radius	136±5 pm
Van der Waals radius	175 pm
Miscellanea
Crystal structure	​face-centered cubic (fcc)
Speed of sound thin rod	2800 m/s (at r.t.)
Thermal expansion	8.8 µm/(m·K) (at 25 °C)
Thermal conductivity	71.6 W/(m·K)
Electrical resistivity	105 nΩ·m (at 20 °C)
Magnetic ordering	paramagnetic
Tensile strength	125–240 MPa
Young's modulus	168 GPa
Shear modulus	61 GPa
Bulk modulus	230 GPa
Poisson ratio	0.38
Mohs hardness	3.5
Vickers hardness	400–550 MPa
Brinell hardness	300–500 MPa
CAS Number	7440-06-4
History
Discovery and first isolation	Antonio de Ulloa (1735)
Most stable isotopes of platinum
iso NA half-life DM DE (MeV) DP 190Pt 0.014% 6.5×1011 y α 3.252 186Os 192Pt 0.782% >4.7×1016 y (α) 2.4181 188Os 193Pt syn 50 y ε – 193Ir 194Pt 32.967% – (α) 1.5045 190Os 195Pt 33.832% – (α) 1.1581 191Os 196Pt 25.242% – (α) 0.7942 192Os 198Pt 7.163% >3.2×1014 y (α) 0.0870 194Os (β−β−) 1.0472 198Hg
Decay modes in parentheses are predicted, but have not yet been observed

References

These references will appear in the article, but this list appears only on this page.