Sodium (Na, Z = 11)
Métal alcalin Bloc s Groupe 1 Période 3 Solide (CNTP)
Sodium /ˈsoʊdiəm/ is a chemical element with symbol Na (from Ancient Greek Νάτριο) and atomic number 11. It is a soft, silver-white, highly reactive metal. In the Periodic table it is in column 1 (alkali metals), and shares with the other six elements in that column that it has a single electron in its outer shell, which it readily donates, creating a positively charged atom - a cation.
Découvreur : Humphry Davy
Propriétés physiques
- Masse atomique standard
- 22,99 u
- Densité
- 0,9680 g/cm³
- Point de fusion
- 370,9 K
- Point d'ébullition
- 1 156,1 K
- Chaleur molaire
- 28,23 J·mol⁻¹·K⁻¹
- Électronégativité (Pauling)
- 0,9300
- Affinité électronique
- 52,87 kJ/mol
- Énergies d'ionisation
- 496 ; 4 562 ; 6 910 ; 9 543 kJ/mol
- Configuration électronique
- [Ne] 3s1
- Électrons par couche
- K : 2 · L : 8 · M : 1
- Aspect
- silvery white metallic
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 418 ANU (atomes ultimes), soit N/18 = 23,22 — masse « noologique » à comparer à la masse standard 22,990 u et à l'isotope dominant 23Na. Coefficient k(Z) = 1,172
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (23)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 17Na | 17 | 6 | 17,037273 | — | stable | 1/2 | ⁺ | — |
| 18Na | 18 | 7 | 18,026879 | — | 1.3 zs | 1 | ⁻ | — |
| 19Na | 19 | 8 | 19,013880 | — | — | 5/2 | ⁺ | N magique |
| 20Na | 20 | 9 | 20,007354 | — | 447.9 ms | 2 | ⁺ | — |
| 21Na | 21 | 10 | 20,997654 | — | 22.455 s | 3/2 | ⁺ | — |
| 22Na | 22 | 11 | 21,994438 | — | 2.6019 an | 3 | ⁺ | — |
| 23Na | 23 | 12 | 22,989769 | 100,0000 | stable | 3/2 | ⁺ | — |
| 24Na | 24 | 13 | 23,990963 | — | 14.956 h | 4 | ⁺ | — |
| 25Na | 25 | 14 | 24,989954 | — | 59.1 s | 5/2 | ⁺ | — |
| 26Na | 26 | 15 | 25,992635 | — | 1071.28 ms | 3 | ⁺ | — |
| 27Na | 27 | 16 | 26,994076 | — | 301 ms | 5/2 | ⁺ | — |
| 28Na | 28 | 17 | 27,998939 | — | 33.1 ms | 1 | ⁺ | — |
| 29Na | 29 | 18 | 29,002877 | — | 43.2 ms | 3/2 | ⁺ | — |
| 30Na | 30 | 19 | 30,009098 | — | 45.9 ms | 2 | ⁺ | — |
| 31Na | 31 | 20 | 31,013147 | — | 16.8 ms | 3/2 | ⁺ | N magique |
| 32Na | 32 | 21 | 32,020011 | — | 12.9 ms | 3 | ⁻ | — |
| 33Na | 33 | 22 | 33,025529 | — | 8.2 ms | 3/2 | ⁺ | — |
| 34Na | 34 | 23 | 34,034010 | — | 5.5 ms | 1 | ⁺ | — |
| 35Na | 35 | 24 | 35,040614 | — | 1.5 ms | 3/2 | ⁺ | — |
| 36Na | 36 | 25 | 36,049279 | — | stable | — | — | |
| 37Na | 37 | 26 | 37,057042 | — | — | 3/2 | ⁺ | — |
| 38Na | 38 | 27 | 38,066458 | — | stable | — | — | |
| 39Na | 39 | 28 | 39,075123 | — | — | 3/2 | ⁺ | N magique |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.