Niobium (Nb, Z = 41)
Métal de transition Bloc d Groupe 5 Période 5 Solide (CNTP)
Niobium, formerly columbium, is a chemical element with symbol Nb (formerly Cb) and atomic number 41. It is a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite. The name comes from Greek mythology:Niobe, daughter of Tantalus since it is so similar to tantalum.
Découvreur : Charles Hatchett
Propriétés physiques
- Masse atomique standard
- 92,91 u
- Densité
- 8,570 g/cm³
- Point de fusion
- 2 750,0 K
- Point d'ébullition
- 5 017,0 K
- Chaleur molaire
- 24,60 J·mol⁻¹·K⁻¹
- Électronégativité (Pauling)
- 1,600
- Affinité électronique
- 88,52 kJ/mol
- Énergies d'ionisation
- 652 ; 1 380 ; 2 416 ; 3 700 kJ/mol
- Configuration électronique
- [Kr] 4d4 5s1
- Électrons par couche
- K : 2 · L : 8 · M : 18 · N : 12 · O : 1
- Aspect
- gray metallic, bluish when oxidized
Correspondance ANU historique / conjectural
Comptage de la Chimie Occulte (1908) : 1 719 ANU (atomes ultimes), soit N/18 = 95,50 — masse « noologique » à comparer à la masse standard 92,906 u et à l'isotope dominant 93Nb. Coefficient k(Z) = 0,991
Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.
Isotopes (38)
| Nucléide | A | N | Masse (u) | Abondance (%) | Demi-vie | Spin | Parité | Magique |
|---|---|---|---|---|---|---|---|---|
| 79Nb | 79 | 38 | 78,966022 | — | stable | 9/2 | ⁺ | — |
| 80Nb | 80 | 39 | 79,958754 | — | stable | 4 | ⁻ | — |
| 81Nb | 81 | 40 | 80,950230 | — | stable | 9/2 | ⁺ | — |
| 82Nb | 82 | 41 | 81,944380 | — | 51 ms | 0 | ⁺ | — |
| 83Nb | 83 | 42 | 82,938150 | — | 3.9 s | 9/2 | ⁺ | — |
| 84Nb | 84 | 43 | 83,934306 | — | 9.8 s | 1 | ⁺ | — |
| 85Nb | 85 | 44 | 84,928846 | — | 20.5 s | 9/2 | ⁺ | — |
| 86Nb | 86 | 45 | 85,925782 | — | 88 s | 6 | ⁺ | — |
| 87Nb | 87 | 46 | 86,920692 | — | 3.7 min | 1/2 | — | |
| 88Nb | 88 | 47 | 87,918226 | — | 14.5 min | 8 | ⁺ | — |
| 89Nb | 89 | 48 | 88,913445 | — | 2.03 h | 9/2 | ⁺ | — |
| 90Nb | 90 | 49 | 89,911259 | — | 14.6 h | 8 | ⁺ | — |
| 91Nb | 91 | 50 | 90,906990 | — | 680 an | 9/2 | ⁺ | N magique |
| 92Nb | 92 | 51 | 91,907189 | — | 34.7 Ma | 7 | ⁺ | — |
| 93Nb | 93 | 52 | 92,906373 | 100,0000 | stable | 9/2 | ⁺ | — |
| 94Nb | 94 | 53 | 93,907279 | — | 20.4 ka | 6 | ⁺ | — |
| 95Nb | 95 | 54 | 94,906831 | — | 34.991 j | 9/2 | ⁺ | — |
| 96Nb | 96 | 55 | 95,908102 | — | 23.35 h | 6 | ⁺ | — |
| 97Nb | 97 | 56 | 96,908102 | — | 72.1 min | 9/2 | ⁺ | — |
| 98Nb | 98 | 57 | 97,910333 | — | 2.86 s | 1 | ⁺ | — |
| 99Nb | 99 | 58 | 98,911609 | — | 15 s | 9/2 | ⁺ | — |
| 100Nb | 100 | 59 | 99,914341 | — | 1.5 s | 1 | ⁺ | — |
| 101Nb | 101 | 60 | 100,915307 | — | 7.1 s | 5/2 | ⁺ | — |
| 102Nb | 102 | 61 | 101,918090 | — | 4.3 s | 4 | ⁺ | — |
| 103Nb | 103 | 62 | 102,919453 | — | 1.34 s | 5/2 | ⁺ | — |
| 104Nb | 104 | 63 | 103,922908 | — | 0.98 s | 5 | ⁻ | — |
| 105Nb | 105 | 64 | 104,924943 | — | 2.91 s | 5/2 | ⁺ | — |
| 106Nb | 106 | 65 | 105,928929 | — | 900 ms | 1 | ⁻ | — |
| 107Nb | 107 | 66 | 106,931590 | — | 286 ms | 5/2 | ⁺ | — |
| 108Nb | 108 | 67 | 107,936076 | — | 201 ms | 2 | ⁺ | — |
| 109Nb | 109 | 68 | 108,939141 | — | 106.9 ms | 3/2 | ⁻ | — |
| 110Nb | 110 | 69 | 109,943843 | — | 75 ms | 5 | ⁺ | — |
| 111Nb | 111 | 70 | 110,947439 | — | 54 ms | 3/2 | ⁻ | — |
| 112Nb | 112 | 71 | 111,952689 | — | 38 ms | 1 | ⁺ | — |
| 113Nb | 113 | 72 | 112,956833 | — | 32 ms | 3/2 | ⁻ | — |
| 114Nb | 114 | 73 | 113,962469 | — | 17 ms | 2 | ⁻ | — |
| 115Nb | 115 | 74 | 114,966849 | — | 23 ms | 3/2 | ⁻ | — |
| 116Nb | 116 | 75 | 115,972914 | — | — | 1 | ⁻ | — |
Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.