Platine (Pt, Z = 78)
Métal de transition Bloc d Groupe 10 Période 6 Solide (CNTP)
Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal. Its name is derived from the Spanish term platina, which is literally translated into "little silver".
Découvreur : Antonio de Ulloa
Propriétés physiques
- Masse atomique standard
- 195,1 u
- Densité
- 21,45 g/cm³
- Point de fusion
- 2 041,4 K
- Point d'ébullition
- 4 098,0 K
- Chaleur molaire
- 25,86 J·mol⁻¹·K⁻¹
- Électronégativité (Pauling)
- 2,280
- Affinité électronique
- 205,0 kJ/mol
- Énergies d'ionisation
- 870 ; 1 791 kJ/mol
- Configuration électronique
- [Xe] 4f14 5d9 6s1
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 32 · O : 17 · P : 1
- Aspect
- silvery white
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 3 486 ANU (atomes ultimes), soit N/18 = 193,67 — masse « noologique » à comparer à la masse standard 195,085 u et à l'isotope dominant 195Pt. Coefficient k(Z) = 0,903
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (44)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 165Pt | 165 | 87 | 164,999658 | — | 370 µs | 7/2 | ⁻ | — |
| 166Pt | 166 | 88 | 165,994866 | — | 294 µs | 0 | ⁺ | — |
| 167Pt | 167 | 89 | 166,992750 | — | 915 µs | 7/2 | ⁻ | — |
| 168Pt | 168 | 90 | 167,988180 | — | 2.02 ms | 0 | ⁺ | — |
| 169Pt | 169 | 91 | 168,986619 | — | 6.99 ms | 7/2 | ⁻ | — |
| 170Pt | 170 | 92 | 169,982502 | — | 13.93 ms | 0 | ⁺ | — |
| 171Pt | 171 | 93 | 170,981249 | — | 45.5 ms | 7/2 | ⁻ | — |
| 172Pt | 172 | 94 | 171,977341 | — | 97.6 ms | 0 | ⁺ | — |
| 173Pt | 173 | 95 | 172,976450 | — | 382 ms | 5/2 | ⁻ | — |
| 174Pt | 174 | 96 | 173,972820 | — | 862 ms | 0 | ⁺ | — |
| 175Pt | 175 | 97 | 174,972401 | — | 2.43 s | 7/2 | ⁻ | — |
| 176Pt | 176 | 98 | 175,968938 | — | 6.33 s | 0 | ⁺ | — |
| 177Pt | 177 | 99 | 176,968470 | — | 10 s | 5/2 | ⁻ | — |
| 178Pt | 178 | 100 | 177,965649 | — | 20.7 s | 0 | ⁺ | — |
| 179Pt | 179 | 101 | 178,965359 | — | 21.2 s | 1/2 | ⁻ | — |
| 180Pt | 180 | 102 | 179,963038 | — | 56 s | 0 | ⁺ | — |
| 181Pt | 181 | 103 | 180,963090 | — | 52 s | 1/2 | ⁻ | — |
| 182Pt | 182 | 104 | 181,961172 | — | 2.67 min | 0 | ⁺ | — |
| 183Pt | 183 | 105 | 182,961596 | — | 6.5 min | 1/2 | ⁻ | — |
| 184Pt | 184 | 106 | 183,959922 | — | 17.3 min | 0 | ⁺ | — |
| 185Pt | 185 | 107 | 184,960614 | — | 70.9 min | 9/2 | ⁺ | — |
| 186Pt | 186 | 108 | 185,959351 | — | 2.08 h | 0 | ⁺ | — |
| 187Pt | 187 | 109 | 186,960617 | — | 2.35 h | 3/2 | ⁻ | — |
| 188Pt | 188 | 110 | 187,959398 | — | 10.16 j | 0 | ⁺ | — |
| 189Pt | 189 | 111 | 188,960848 | — | 10.87 h | 3/2 | ⁻ | — |
| 190Pt | 190 | 112 | 189,959950 | 0,0120 | 483 Ga | 0 | ⁺ | — |
| 191Pt | 191 | 113 | 190,961676 | — | 2.83 j | 3/2 | ⁻ | — |
| 192Pt | 192 | 114 | 191,961043 | 0,7820 | stable | 0 | ⁺ | — |
| 193Pt | 193 | 115 | 192,962985 | — | 50 an | 1/2 | ⁻ | — |
| 194Pt | 194 | 116 | 193,962683 | 32,8640 | stable | 0 | ⁺ | — |
| 195Pt | 195 | 117 | 194,964794 | 33,7750 | stable | 1/2 | ⁻ | — |
| 196Pt | 196 | 118 | 195,964955 | 25,2110 | stable | 0 | ⁺ | — |
| 197Pt | 197 | 119 | 196,967343 | — | 19.8915 h | 1/2 | ⁻ | — |
| 198Pt | 198 | 120 | 197,967897 | 7,3560 | stable | 0 | ⁺ | — |
| 199Pt | 199 | 121 | 198,970597 | — | 30.8 min | 5/2 | ⁻ | — |
| 200Pt | 200 | 122 | 199,971445 | — | 12.6 h | 0 | ⁺ | — |
| 201Pt | 201 | 123 | 200,974513 | — | 2.5 min | 5/2 | ⁻ | — |
| 202Pt | 202 | 124 | 201,975639 | — | 44 h | 0 | ⁺ | — |
| 203Pt | 203 | 125 | 202,979055 | — | 22 s | 1/2 | ⁻ | — |
| 204Pt | 204 | 126 | 203,981084 | — | 10.3 s | 0 | ⁺ | N magique |
| 205Pt | 205 | 127 | 204,986237 | — | — | 9/2 | ⁺ | — |
| 206Pt | 206 | 128 | 205,990080 | — | — | 0 | ⁺ | — |
| 207Pt | 207 | 129 | 206,995556 | — | — | 9/2 | ⁺ | — |
| 208Pt | 208 | 130 | 207,999463 | — | — | 0 | ⁺ | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.