Prométhium (Pm, Z = 61)
Lanthanide Bloc f Groupe 3 Période 6 Solide (CNTP)
Promethium, originally prometheum, is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is one of only two such elements that are followed in the periodic table by elements with stable forms, a distinction shared with technetium. Chemically, promethium is a lanthanide, which forms salts when combined with other elements.
Découvreur : Chien Shiung Wu
Propriétés physiques
- Masse atomique standard
- 145,0 u
- Densité
- 7,260 g/cm³
- Point de fusion
- 1 315,0 K
- Point d'ébullition
- 3 273,0 K
- Chaleur molaire
- —
- Électronégativité (Pauling)
- 1,130
- Affinité électronique
- 12,45 kJ/mol
- Énergies d'ionisation
- 540 ; 1 050 ; 2 150 ; 3 970 kJ/mol
- Configuration électronique
- [Xe] 4f5 6s2
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 23 · O : 8 · P : 2
- Aspect
- metallic
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 2 640 ANU (atomes ultimes), soit N/18 = 146,67 — masse « noologique » à comparer à la masse standard 145,000 u et à l'isotope dominant 145Pm. Coefficient k(Z) = 0,937
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (40)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 126Pm | 126 | 65 | 125,957327 | — | — | — | — | |
| 127Pm | 127 | 66 | 126,951358 | — | — | 3/2 | ⁺ | — |
| 128Pm | 128 | 67 | 127,948234 | — | 1 s | 4 | ⁺ | — |
| 129Pm | 129 | 68 | 128,942909 | — | 2.4 s | 5/2 | ⁺ | — |
| 130Pm | 130 | 69 | 129,940451 | — | 2.6 s | 5 | ⁺ | — |
| 131Pm | 131 | 70 | 130,935834 | — | 6.3 s | 11/2 | ⁻ | — |
| 132Pm | 132 | 71 | 131,933840 | — | 6.2 s | 3 | ⁺ | — |
| 133Pm | 133 | 72 | 132,929782 | — | 13.5 s | 3/2 | ⁺ | — |
| 134Pm | 134 | 73 | 133,928326 | — | 22 s | 5 | ⁺ | — |
| 135Pm | 135 | 74 | 134,924785 | — | 49 s | 3/2 | ⁺ | — |
| 136Pm | 136 | 75 | 135,923596 | — | 107 s | 7 | ⁺ | — |
| 137Pm | 137 | 76 | 136,920480 | — | — | 5/2 | ⁻ | — |
| 138Pm | 138 | 77 | 137,919576 | — | 3.24 min | 3 | ⁺ | — |
| 139Pm | 139 | 78 | 138,916799 | — | 4.15 min | 5/2 | — | |
| 140Pm | 140 | 79 | 139,916036 | — | 9.2 s | 1 | ⁺ | — |
| 141Pm | 141 | 80 | 140,913555 | — | 20.9 min | 5/2 | ⁺ | — |
| 142Pm | 142 | 81 | 141,912891 | — | 40.5 s | 1 | ⁺ | — |
| 143Pm | 143 | 82 | 142,910938 | — | 265 j | 5/2 | ⁺ | N magique |
| 144Pm | 144 | 83 | 143,912596 | — | 363 j | 5 | ⁻ | — |
| 145Pm | 145 | 84 | 144,912756 | — | 17.7 an | 5/2 | ⁺ | — |
| 146Pm | 146 | 85 | 145,914702 | — | 5.53 an | 3 | ⁻ | — |
| 147Pm | 147 | 86 | 146,915145 | — | 2.6234 an | 7/2 | ⁺ | — |
| 148Pm | 148 | 87 | 147,917481 | — | 5.368 j | 1 | ⁻ | — |
| 149Pm | 149 | 88 | 148,918342 | — | 53.08 h | 7/2 | ⁺ | — |
| 150Pm | 150 | 89 | 149,920990 | — | 2.698 h | 1 | ⁻ | — |
| 151Pm | 151 | 90 | 150,921217 | — | 28.4 h | 5/2 | — | |
| 152Pm | 152 | 91 | 151,923505 | — | 4.12 min | 1 | ⁺ | — |
| 153Pm | 153 | 92 | 152,924156 | — | 5.25 min | 5/2 | ⁻ | — |
| 154Pm | 154 | 93 | 153,926713 | — | 2.68 min | 4 | ⁺ | — |
| 155Pm | 155 | 94 | 154,928137 | — | 41.5 s | 5/2 | ⁻ | — |
| 156Pm | 156 | 95 | 155,931114 | — | 27.4 s | 4 | ⁺ | — |
| 157Pm | 157 | 96 | 156,933121 | — | 10.56 s | 5/2 | ⁻ | — |
| 158Pm | 158 | 97 | 157,936547 | — | 4.8 s | 0 | ⁺ | — |
| 159Pm | 159 | 98 | 158,939286 | — | 1.49 s | 5/2 | ⁻ | — |
| 160Pm | 160 | 99 | 159,943215 | — | 725 ms | 6 | ⁻ | — |
| 161Pm | 161 | 100 | 160,946230 | — | 1.05 s | 5/2 | ⁻ | — |
| 162Pm | 162 | 101 | 161,950574 | — | 630 ms | 2 | ⁺ | — |
| 163Pm | 163 | 102 | 162,953881 | — | 255 ms | 5/2 | ⁻ | — |
| 164Pm | 164 | 103 | 163,958819 | — | — | 5 | ⁻ | — |
| 165Pm | 165 | 104 | 164,962780 | — | — | 5/2 | ⁻ | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.