Gallium (Ga, Z = 31)
Métal pauvre Bloc p Groupe 13 Période 4 Solide (CNTP)
Gallium is a chemical element with symbol Ga and atomic number 31. Elemental gallium does not occur in free form in nature, but as the gallium(III) compounds that are in trace amounts in zinc ores and in bauxite. Gallium is a soft, silvery metal, and elemental gallium is a brittle solid at low temperatures, and melts at 29.76 °C (85.57 °F) (slightly above room temperature).
Découvreur : Lecoq de Boisbaudran
Propriétés physiques
- Masse atomique standard
- 69,72 u
- Densité
- 5,910 g/cm³
- Point de fusion
- 302,9 K
- Point d'ébullition
- 2 673,0 K
- Chaleur molaire
- 25,86 J·mol⁻¹·K⁻¹
- Électronégativité (Pauling)
- 1,810
- Affinité électronique
- 41,00 kJ/mol
- Énergies d'ionisation
- 579 ; 1 979 ; 2 963 ; 6 180 kJ/mol
- Configuration électronique
- [Ar] 3d10 4s2 4p1
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 3
- Aspect
- silver-white
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 1 260 ANU (atomes ultimes), soit N/18 = 70,00 — masse « noologique » à comparer à la masse standard 69,723 u et à l'isotope dominant 69Ga. Coefficient k(Z) = 1,030 · multiple de 18
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (33)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 56Ga | 56 | 25 | 55,995878 | — | stable | 3 | ⁺ | — |
| 57Ga | 57 | 26 | 56,983457 | — | stable | 1/2 | ⁻ | — |
| 58Ga | 58 | 27 | 57,974729 | — | stable | 2 | ⁺ | — |
| 59Ga | 59 | 28 | 58,963757 | — | stable | 3/2 | ⁻ | N magique |
| 60Ga | 60 | 29 | 59,957498 | — | 72.4 ms | 2 | ⁺ | — |
| 61Ga | 61 | 30 | 60,949399 | — | 165.9 ms | 3/2 | ⁻ | — |
| 62Ga | 62 | 31 | 61,944190 | — | 116.122 ms | 0 | ⁺ | — |
| 63Ga | 63 | 32 | 62,939294 | — | 32.4 s | 3/2 | ⁻ | — |
| 64Ga | 64 | 33 | 63,936840 | — | 2.627 min | 0 | — | |
| 65Ga | 65 | 34 | 64,932734 | — | 15.133 min | 3/2 | ⁻ | — |
| 66Ga | 66 | 35 | 65,931590 | — | 9.304 h | 0 | ⁺ | — |
| 67Ga | 67 | 36 | 66,928202 | — | 3.2617 j | 3/2 | ⁻ | — |
| 68Ga | 68 | 37 | 67,927980 | — | 67.842 min | 1 | ⁺ | — |
| 69Ga | 69 | 38 | 68,925574 | 60,1080 | stable | 3/2 | ⁻ | — |
| 70Ga | 70 | 39 | 69,926022 | — | 21.14 min | 1 | ⁺ | — |
| 71Ga | 71 | 40 | 70,924703 | 39,8920 | stable | 3/2 | ⁻ | — |
| 72Ga | 72 | 41 | 71,926367 | — | 14.025 h | 3 | ⁻ | — |
| 73Ga | 73 | 42 | 72,925175 | — | 4.86 h | 3/2 | ⁻ | — |
| 74Ga | 74 | 43 | 73,926946 | — | 8.12 min | 3 | ⁻ | — |
| 75Ga | 75 | 44 | 74,926504 | — | 126 s | 3/2 | ⁻ | — |
| 76Ga | 76 | 45 | 75,928828 | — | 30.6 s | 2 | ⁺ | — |
| 77Ga | 77 | 46 | 76,929154 | — | 13.2 s | 3/2 | ⁻ | — |
| 78Ga | 78 | 47 | 77,931611 | — | 5.09 s | 2 | ⁺ | — |
| 79Ga | 79 | 48 | 78,932852 | — | 2.848 s | 3/2 | ⁻ | — |
| 80Ga | 80 | 49 | 79,936421 | — | 1.9 s | 3 | ⁻ | — |
| 81Ga | 81 | 50 | 80,938134 | — | 1.217 s | 5/2 | ⁻ | N magique |
| 82Ga | 82 | 51 | 81,943177 | — | 600 ms | 2 | ⁻ | — |
| 83Ga | 83 | 52 | 82,947120 | — | 310 ms | 5/2 | ⁻ | — |
| 84Ga | 84 | 53 | 83,952663 | — | 97.6 ms | 0 | ⁻ | — |
| 85Ga | 85 | 54 | 84,957333 | — | 95.3 ms | 5/2 | ⁻ | — |
| 86Ga | 86 | 55 | 85,963757 | — | 49 ms | — | — | |
| 87Ga | 87 | 56 | 86,969007 | — | 29 ms | 5/2 | ⁻ | — |
| 88Ga | 88 | 57 | 87,975963 | — | stable | — | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.