Chrome (Cr, Z = 24)
Métal de transition Bloc d Groupe 6 Période 4 Solide (CNTP)
Chromium is a chemical element with symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard and brittle metal which takes a high polish, resists tarnishing, and has a high melting point.
Découvreur : Louis Nicolas Vauquelin
Propriétés physiques
- Masse atomique standard
- 52,00 u
- Densité
- 7,190 g/cm³
- Point de fusion
- 2 180,0 K
- Point d'ébullition
- 2 944,0 K
- Chaleur molaire
- 23,35 J·mol⁻¹·K⁻¹
- Électronégativité (Pauling)
- 1,660
- Affinité électronique
- 65,21 kJ/mol
- Énergies d'ionisation
- 653 ; 1 591 ; 2 987 ; 4 743 kJ/mol
- Configuration électronique
- [Ar] 3d5 4s1
- Électrons par couche
- K : 2 · L : 8 · M : 13 · N : 1
- Aspect
- silvery metallic
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 936 ANU (atomes ultimes), soit N/18 = 52,00 — masse « noologique » à comparer à la masse standard 51,996 u et à l'isotope dominant 52Cr. Coefficient k(Z) = 1,065 · multiple de 18
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (30)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 41Cr | 41 | 17 | 41,021911 | — | stable | 3/2 | ⁺ | — |
| 42Cr | 42 | 18 | 42,007579 | — | 13.3 ms | 0 | ⁺ | — |
| 43Cr | 43 | 19 | 42,997885 | — | 21.1 ms | 3/2 | ⁺ | — |
| 44Cr | 44 | 20 | 43,985591 | — | 42.8 ms | 0 | ⁺ | N magique |
| 45Cr | 45 | 21 | 44,979050 | — | 60.9 ms | 7/2 | ⁻ | — |
| 46Cr | 46 | 22 | 45,968361 | — | 224.3 ms | 0 | ⁺ | — |
| 47Cr | 47 | 23 | 46,962895 | — | 461.6 ms | 3/2 | ⁻ | — |
| 48Cr | 48 | 24 | 47,954029 | — | 21.56 h | 0 | ⁺ | — |
| 49Cr | 49 | 25 | 48,951334 | — | 42.3 min | 5/2 | ⁻ | — |
| 50Cr | 50 | 26 | 49,946042 | 4,3450 | stable | 0 | ⁺ | — |
| 51Cr | 51 | 27 | 50,944765 | — | 27.7015 j | 7/2 | ⁻ | — |
| 52Cr | 52 | 28 | 51,940505 | 83,7890 | stable | 0 | ⁺ | N magique |
| 53Cr | 53 | 29 | 52,940646 | 9,5010 | stable | 3/2 | ⁻ | — |
| 54Cr | 54 | 30 | 53,938877 | 2,3650 | stable | 0 | ⁺ | — |
| 55Cr | 55 | 31 | 54,940837 | — | 3.497 min | 3/2 | ⁻ | — |
| 56Cr | 56 | 32 | 55,940649 | — | 5.94 min | 0 | ⁺ | — |
| 57Cr | 57 | 33 | 56,943612 | — | 21.1 s | 3/2 | — | |
| 58Cr | 58 | 34 | 57,944185 | — | 7 s | 0 | ⁺ | — |
| 59Cr | 59 | 35 | 58,948345 | — | 1050 ms | 1/2 | ⁻ | — |
| 60Cr | 60 | 36 | 59,949642 | — | 490 ms | 0 | ⁺ | — |
| 61Cr | 61 | 37 | 60,954378 | — | 243 ms | 5/2 | ⁻ | — |
| 62Cr | 62 | 38 | 61,956143 | — | 206 ms | 0 | ⁺ | — |
| 63Cr | 63 | 39 | 62,961161 | — | 129 ms | 1/2 | ⁻ | — |
| 64Cr | 64 | 40 | 63,963886 | — | 43 ms | 0 | ⁺ | — |
| 65Cr | 65 | 41 | 64,969608 | — | 27.5 ms | 1/2 | ⁻ | — |
| 66Cr | 66 | 42 | 65,973011 | — | 23.8 ms | 0 | ⁺ | — |
| 67Cr | 67 | 43 | 66,979313 | — | — | 1/2 | ⁻ | — |
| 68Cr | 68 | 44 | 67,983156 | — | — | 0 | ⁺ | — |
| 69Cr | 69 | 45 | 68,989662 | — | — | 7/2 | ⁺ | — |
| 70Cr | 70 | 46 | 69,993945 | — | — | 0 | ⁺ | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.