Thorium (Th, Z = 90)
Actinide Bloc f Groupe 3 Période 7 Solide (CNTP)
Thorium is a chemical element with symbol Th and atomic number 90. A radioactive actinide metal, thorium is one of only two significantly radioactive elements that still occur naturally in large quantities as a primordial element (the other being uranium). It was discovered in 1828 by the Norwegian Reverend and amateur mineralogist Morten Thrane Esmark and identified by the Swedish chemist Jöns Jakob Berzelius, who named it after Thor, the Norse god of thunder.
Découvreur : Jöns Jakob Berzelius
Propriétés physiques
- Masse atomique standard
- 232,0 u
- Densité
- 11,72 g/cm³
- Point de fusion
- 2 023,0 K
- Point d'ébullition
- 5 061,0 K
- Chaleur molaire
- 26,23 J·mol⁻¹·K⁻¹
- Électronégativité (Pauling)
- 1,300
- Affinité électronique
- 112,7 kJ/mol
- Énergies d'ionisation
- 587 ; 1 110 ; 1 930 ; 2 780 kJ/mol
- Configuration électronique
- [Rn] 6d2 7s2
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 32 · O : 18 · P : 10 · Q : 2
- Aspect
- silvery, often with black tarnish
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 4 187 ANU (atomes ultimes), soit N/18 = 232,61 — masse « noologique » à comparer à la masse standard 232,038 u et à l'isotope dominant 232Th. Coefficient k(Z) = 0,884
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (32)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 208Th | 208 | 118 | 208,017915 | — | 2.4 ms | 0 | ⁺ | — |
| 209Th | 209 | 119 | 209,017601 | — | — | 5/2 | ⁻ | — |
| 210Th | 210 | 120 | 210,015094 | — | 16 ms | 0 | ⁺ | — |
| 211Th | 211 | 121 | 211,014897 | — | 48 ms | 5/2 | ⁻ | — |
| 212Th | 212 | 122 | 212,013002 | — | 31.7 ms | 0 | ⁺ | — |
| 213Th | 213 | 123 | 213,013011 | — | 144 ms | 5/2 | ⁻ | — |
| 214Th | 214 | 124 | 214,011481 | — | 87 ms | 0 | ⁺ | — |
| 215Th | 215 | 125 | 215,011725 | — | 1.35 s | 1/2 | ⁻ | — |
| 216Th | 216 | 126 | 216,011056 | — | 26.28 ms | 0 | ⁺ | N magique |
| 217Th | 217 | 127 | 217,013103 | — | 248 µs | 9/2 | ⁺ | — |
| 218Th | 218 | 128 | 218,013276 | — | 122 ns | 0 | ⁺ | — |
| 219Th | 219 | 129 | 219,015526 | — | 1.023 µs | 9/2 | ⁺ | — |
| 220Th | 220 | 130 | 220,015770 | — | 10.2 µs | 0 | ⁺ | — |
| 221Th | 221 | 131 | 221,018186 | — | 1.75 ms | 7/2 | ⁺ | — |
| 222Th | 222 | 132 | 222,018468 | — | 2.24 ms | 0 | ⁺ | — |
| 223Th | 223 | 133 | 223,020811 | — | 600 ms | 5/2 | — | |
| 224Th | 224 | 134 | 224,021466 | — | 1.04 s | 0 | ⁺ | — |
| 225Th | 225 | 135 | 225,023951 | — | 8.75 min | 3/2 | ⁺ | — |
| 226Th | 226 | 136 | 226,024904 | — | 30.7 min | 0 | ⁺ | — |
| 227Th | 227 | 137 | 227,027703 | — | 18.693 j | 1/2 | ⁺ | — |
| 228Th | 228 | 138 | 228,028740 | — | 1.9125 an | 0 | ⁺ | — |
| 229Th | 229 | 139 | 229,031761 | — | 7.916 ka | 5/2 | ⁺ | — |
| 230Th | 230 | 140 | 230,033132 | 0,0200 | 75.4 ka | 0 | ⁺ | — |
| 231Th | 231 | 141 | 231,036303 | — | 25.52 h | 5/2 | ⁺ | — |
| 232Th | 232 | 142 | 232,038054 | 99,9800 | 14 Ga | 0 | ⁺ | — |
| 233Th | 233 | 143 | 233,041580 | — | 21.83 min | 1/2 | ⁺ | — |
| 234Th | 234 | 144 | 234,043600 | — | 24.107 j | 0 | ⁺ | — |
| 235Th | 235 | 145 | 235,047255 | — | 7.2 min | 1/2 | ⁺ | — |
| 236Th | 236 | 146 | 236,049657 | — | 37.3 min | 0 | ⁺ | — |
| 237Th | 237 | 147 | 237,053629 | — | 4.8 min | 5/2 | ⁺ | — |
| 238Th | 238 | 148 | 238,056388 | — | 9.4 min | 0 | ⁺ | — |
| 239Th | 239 | 149 | 239,060655 | — | — | 7/2 | ⁺ | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.