Strontium (Sr, Z = 38)
Métal alcalino-terreux Bloc s Groupe 2 Période 5 Solide (CNTP)
Strontium is a chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when it is exposed to air.
Découvreur : William Cruickshank (chemist)
Propriétés physiques
- Masse atomique standard
- 87,62 u
- Densité
- 2,640 g/cm³
- Point de fusion
- 1 050,0 K
- Point d'ébullition
- 1 650,0 K
- Chaleur molaire
- 26,40 J·mol⁻¹·K⁻¹
- Électronégativité (Pauling)
- 0,9500
- Affinité électronique
- 5,023 kJ/mol
- Énergies d'ionisation
- 550 ; 1 064 ; 4 138 ; 5 500 kJ/mol
- Configuration électronique
- [Kr] 5s2
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 8 · O : 2
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 1 568 ANU (atomes ultimes), soit N/18 = 87,11 — masse « noologique » à comparer à la masse standard 87,621 u et à l'isotope dominant 88Sr. Coefficient k(Z) = 1,002
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (35)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 73Sr | 73 | 35 | 72,965700 | — | 25.3 ms | 5/2 | ⁻ | — |
| 74Sr | 74 | 36 | 73,956170 | — | 27.6 ms | 0 | ⁺ | — |
| 75Sr | 75 | 37 | 74,949953 | — | 85.2 ms | 3/2 | ⁻ | — |
| 76Sr | 76 | 38 | 75,941763 | — | 7.89 s | 0 | ⁺ | — |
| 77Sr | 77 | 39 | 76,937945 | — | 9 s | 5/2 | ⁺ | — |
| 78Sr | 78 | 40 | 77,932180 | — | 156.1 s | 0 | ⁺ | — |
| 79Sr | 79 | 41 | 78,929705 | — | 2.25 min | 3/2 | ⁻ | — |
| 80Sr | 80 | 42 | 79,924518 | — | 106.3 min | 0 | ⁺ | — |
| 81Sr | 81 | 43 | 80,923211 | — | 22.3 min | 1/2 | ⁻ | — |
| 82Sr | 82 | 44 | 81,918400 | — | 25.35 j | 0 | ⁺ | — |
| 83Sr | 83 | 45 | 82,917554 | — | 32.41 h | 7/2 | ⁺ | — |
| 84Sr | 84 | 46 | 83,913419 | 0,5600 | stable | 0 | ⁺ | — |
| 85Sr | 85 | 47 | 84,912932 | — | 64.846 j | 9/2 | ⁺ | — |
| 86Sr | 86 | 48 | 85,909261 | 9,8600 | stable | 0 | ⁺ | — |
| 87Sr | 87 | 49 | 86,908877 | 7,0000 | stable | 9/2 | ⁺ | — |
| 88Sr | 88 | 50 | 87,905612 | 82,5800 | stable | 0 | ⁺ | N magique |
| 89Sr | 89 | 51 | 88,907451 | — | 50.563 j | 5/2 | ⁺ | — |
| 90Sr | 90 | 52 | 89,907728 | — | 28.91 an | 0 | ⁺ | — |
| 91Sr | 91 | 53 | 90,910196 | — | 9.65 h | 5/2 | ⁺ | — |
| 92Sr | 92 | 54 | 91,911038 | — | 2.611 h | 0 | ⁺ | — |
| 93Sr | 93 | 55 | 92,914024 | — | 7.43 min | 2 | ⁺ | — |
| 94Sr | 94 | 56 | 93,915356 | — | 75.3 s | 0 | ⁺ | — |
| 95Sr | 95 | 57 | 94,919358 | — | 23.9 s | 1/2 | ⁻ | — |
| 96Sr | 96 | 58 | 95,921719 | — | 1.059 s | 0 | ⁺ | — |
| 97Sr | 97 | 59 | 96,926376 | — | 432 ms | 1/2 | ⁻ | — |
| 98Sr | 98 | 60 | 97,928693 | — | 653 ms | 0 | ⁺ | — |
| 99Sr | 99 | 61 | 98,932884 | — | 269.2 ms | 3/2 | ⁺ | — |
| 100Sr | 100 | 62 | 99,935783 | — | 202.1 ms | 0 | ⁺ | — |
| 101Sr | 101 | 63 | 100,940606 | — | 113.7 ms | 5/2 | ⁻ | — |
| 102Sr | 102 | 64 | 101,944005 | — | 69 ms | 0 | ⁺ | — |
| 103Sr | 103 | 65 | 102,949243 | — | 53 ms | 5/2 | ⁺ | — |
| 104Sr | 104 | 66 | 103,953022 | — | 50.6 ms | 0 | ⁺ | — |
| 105Sr | 105 | 67 | 104,959001 | — | 39 ms | 5/2 | ⁺ | — |
| 106Sr | 106 | 68 | 105,963177 | — | 21 ms | 0 | ⁺ | — |
| 107Sr | 107 | 69 | 106,969672 | — | — | 1/2 | ⁺ | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.