Element: Platinum
General data
| Element name | Platinum |
|---|---|
| Chemical symbol | Pt |
| Atomic number Z | 78 |
| Year discovered | 1735 |
| Standard state (25°C) | Solid |
| Category | Transition metal |
| Block | d |
| Atomic mass | 195.08 |
| CPK color | #D0D0E0 |
Physical properties
| Melting point | 2041.55 K (1768.40 °C) |
|---|---|
| Boiling point | 4098 K (3825 °C) |
| Density | 21.46 g/cm³ |
Energy properties
| First ionization energy | 9 eV |
|---|---|
| Electron affinity | 2.128 eV |
Atomic structure
| Protons | 78 (Atomic number) |
|---|---|
| Neutrons (Pt-195, most abundant isotope) | 117 |
| Electrons | 78 |
| Electron configuration | [Xe] 6s¹ 4f¹⁴ 5d⁹ |
| Oxidation states | +4, +2 |
| Electronegativity (Pauling) | 2.28 |
| Atomic radius (van der Waals) | 209 pm |
Ionization energies - NIST ASD (78 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Pt I | 0+ | 8.95883 ± 0.0001 | measured |
| Pt II | 1+ | 18.56 ± 0.12 | measured |
| Pt III | 2+ | 29 ± 1.6 | calculated |
| Pt IV | 3+ | 43 ± 1.7 | calculated |
| Pt V | 4+ | 56 ± 1.9 | calculated |
| Pt VI | 5+ | 75 ± 2 | calculated |
| Pt VII | 6+ | 91 ± 2 | calculated |
| Pt VIII | 7+ | 109 ± 2.1 | calculated |
| Pt IX | 8+ | 126 ± 2.2 | calculated |
| Pt X | 9+ | 144.9 ± 1.1 | semi-empirical |
| Pt XI | 10+ | 220.4 ± 0.9 | semi-empirical |
| Pt XII | 11+ | 245 ± 12 | calculated |
| Pt XIII | 12+ | 269 ± 14 | calculated |
| Pt XIV | 13+ | 293 ± 15 | calculated |
| Pt XV | 14+ | 332 ± 16 | calculated |
| Pt XVI | 15+ | 358 ± 17 | calculated |
| Pt XVII | 16+ | 392 ± 20 | calculated |
| Pt XVIII | 17+ | 445 ± 22 | calculated |
| Pt XIX | 18+ | 479 ± 24 | calculated |
| Pt XX | 19+ | 507 ± 25 | calculated |
| Pt XXI | 20+ | 550 ± 30 | calculated |
| Pt XXII | 21+ | 610 ± 30 | calculated |
| Pt XXIII | 22+ | 660 ± 30 | calculated |
| Pt XXIV | 23+ | 710 ± 40 | calculated |
| Pt XXV | 24+ | 760 ± 40 | calculated |
| Pt XXVI | 25+ | 820 ± 40 | calculated |
| Pt XXVII | 26+ | 870 ± 40 | calculated |
| Pt XXVIII | 27+ | 930 ± 50 | calculated |
| Pt XXIX | 28+ | 980 ± 50 | calculated |
| Pt XXX | 29+ | 1040 ± 50 | calculated |
| Pt XXXI | 30+ | 1090 ± 50 | calculated |
| Pt XXXII | 31+ | 1140 ± 60 | calculated |
| Pt XXXIII | 32+ | 1402 ± 4 | calculated |
| Pt XXXIV | 33+ | 1454 ± 5 | calculated |
| Pt XXXV | 34+ | 1509 ± 5 | calculated |
| Pt XXXVI | 35+ | 1567 ± 5 | calculated |
| Pt XXXVII | 36+ | 1624 ± 5 | calculated |
| Pt XXXVIII | 37+ | 1680 ± 4 | calculated |
| Pt XXXIX | 38+ | 1763 ± 4 | calculated |
| Pt XL | 39+ | 1821 ± 4 | calculated |
| Pt XLI | 40+ | 1883 ± 4 | calculated |
| Pt XLII | 41+ | 1941 ± 4 | calculated |
| Pt XLIII | 42+ | 2171 ± 4 | calculated |
| Pt XLIV | 43+ | 2228 ± 4 | calculated |
| Pt XLV | 44+ | 2291 ± 4 | calculated |
| Pt XLVI | 45+ | 2350 ± 4 | calculated |
| Pt XLVII | 46+ | 2536 ± 4 | calculated |
| Pt XLVIII | 47+ | 2603 ± 4 | calculated |
| Pt XLIX | 48+ | 2762 ± 4 | calculated |
| Pt L | 49+ | 2827.8 ± 1.4 | semi-empirical |
| Pt LI | 50+ | 4715 ± 4 | measured |
| Pt LII | 51+ | 4839 ± 4 | calculated |
| Pt LIII | 52+ | 4980 ± 4 | calculated |
| Pt LIV | 53+ | 5128 ± 5 | calculated |
| Pt LV | 54+ | 5270 ± 5 | calculated |
| Pt LVI | 55+ | 5410 ± 5 | calculated |
| Pt LVII | 56+ | 5654 ± 5 | calculated |
| Pt LVIII | 57+ | 5800 ± 6 | calculated |
| Pt LIX | 58+ | 5959 ± 6 | calculated |
| Pt LX | 59+ | 6106 ± 7 | calculated |
| Pt LXI | 60+ | 6517 ± 10 | calculated |
| Pt LXII | 61+ | 6646 ± 12 | calculated |
| Pt LXIII | 62+ | 6787 ± 15 | calculated |
| Pt LXIV | 63+ | 6918 ± 19 | calculated |
| Pt LXV | 64+ | 7512 ± 24 | calculated |
| Pt LXVI | 65+ | 7660 ± 30 | calculated |
| Pt LXVII | 66+ | 7960 ± 40 | calculated |
| Pt LXVIII | 67+ | 8100 ± 40 | calculated |
| Pt LXIX | 68+ | 17540 ± 50 | calculated |
| Pt LXX | 69+ | 17890 ± 50 | calculated |
| Pt LXXI | 70+ | 18280 ± 60 | calculated |
| Pt LXXII | 71+ | 18630 ± 60 | calculated |
| Pt LXXIII | 72+ | 20840 ± 70 | calculated |
| Pt LXXIV | 73+ | 21280 ± 90 | calculated |
| Pt LXXV | 74+ | 21840 ± 90 | calculated |
| Pt LXXVI | 75+ | 22205.7 ± 0.3 | calculated |
| Pt LXXVII | 76+ | 88955.1 ± 0.3 | calculated |
| Pt LXXVIII | 77+ | 90659.84 ± 0.17 | calculated |
Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.
Photos
Isotopes (44)
| A | N | Half-life | Decay |
|---|---|---|---|
| Pt-165 | 87 | 300 μs | α |
| Pt-166 | 88 | 280 μs | α |
| Pt-167 | 89 | 0.9 ms | α |
| Pt-168 | 90 | 2.02 ms | α |
| Pt-169 | 91 | 6.99 ms | α |
| Pt-170 | 92 | 13.9 ms | α |
| Pt-171 | 93 | 46 ms | α |
| Pt-172 | 94 | 97.4 ms | α |
| Pt-173 | 95 | 374 ms | α |
| Pt-174 | 96 | 0.868 s | α |
| Pt-175 | 97 | 2.43 s | α |
| Pt-176 | 98 | 6.32 s | EC/β⁺ |
| Pt-177 | 99 | 10.0 s | EC/β⁺ |
| Pt-178 | 100 | 21 s | EC/β⁺ |
| Pt-179 | 101 | 21.2 s | EC/β⁺ |
| Pt-180 | 102 | 56 s | EC/β⁺ |
| Pt-181 | 103 | 52.0 s | EC/β⁺ |
| Pt-182 | 104 | 2.7 min | EC/β⁺ |
| Pt-183 | 105 | 6.5 min | EC/β⁺ |
| Pt-184 | 106 | 17.3 min | EC/β⁺ |
| Pt-185 | 107 | 70.9 min | EC/β⁺ |
| Pt-186 | 108 | 2.08 h | EC/β⁺ |
| Pt-187 | 109 | 2.35 h | EC/β⁺ |
| Pt-188 | 110 | 10.2 d | EC/β⁺ |
| Pt-189 | 111 | 10.89 h | EC/β⁺ |
| Pt-190 | 112 | 4.90×10¹¹ a | α |
| Pt-191 | 113 | 2.860 d | EC/β⁺ |
| Pt-192 | 114 | stable | - |
| Pt-193 | 115 | 50 a | EC |
| Pt-194 | 116 | stable | - |
| Pt-195 | 117 | stable | - |
| Pt-196 | 118 | stable | - |
| Pt-197 | 119 | 19.8915 h | β⁻ |
| Pt-198 | 120 | stable | - |
| Pt-199 | 121 | 30.51 min | β⁻ |
| Pt-200 | 122 | 12.6 h | β⁻ |
| Pt-201 | 123 | 2.5 min | β⁻ |
| Pt-202 | 124 | 44 h | β⁻ |
| Pt-203 | 125 | 22 s | β⁻ |
| Pt-204 | 126 | 10.7 s | β⁻ |
| Pt-205 | 127 | unknown | β⁻ |
| Pt-206 | 128 | unknown | β⁻ |
| Pt-207 | 129 | unknown | β⁻ |
| Pt-208 | 130 | unknown | β⁻ |
Data sources
- PubChem Periodic Table API - Retrieved on 29 June 2026 - licence: CC0
- IUPAC CIAAW - Abridged Standard Atomic Weights 2024 - Table version: 2024 - licence: Public domain
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain
- NIST Atomic Spectra Database (ASD) - Retrieved on 29 June 2026 - licence: © U.S. Secretary of Commerce
- Images of Elements - Retrieved on 29 June 2026 - licence: CC BY 3.0