 |
| General |
| Name | Niobium |
| Symbol | Nb |
| Number | 41 |
| Group Number | 5 |
| Group | Transition metals |
| Block | d |
| Density | 8.57 g/cm3 |
| Atomic Weight | 92.9064 g/mol |
| Atomic Volume | 10.87 cm3/mol |
| Discover | 1801 |
|
| States |
| State | Solid |
| Melting Point | 2750 K |
| Boiling Point | 5017 K |
| Triple Point | Nil |
| Critical Point | Nil |
| Heat of Fusion | 30 kJ/mol |
| Heat of Vaporization | 689.9 kJ/mol |
|
| Energies |
| First Ionization Energy | 663.8 kJ/mole |
| Second Ionization Energy | 1381.7 kJ/mole |
| Third Ionization Energy | 2416 kJ/mole |
| Electronegativity | 1.6 |
| Electron Affinity | 86.2 kJ/mole |
| Specific Heat | 0.26 J/gK |
| Heat Atomization | 726 kJ/mole atoms |
|
| Oxidation and Electrons |
| Shells | 2,8,18,12,1 |
| Electron Configuration | [Kr] 4d4 5s1 |
| Minimum Oxidation Number | -1 |
| Maximum Oxidation Number | 5 |
| Minimum Common Oxidation Number | 0 |
| Maximum Common Oxidation Number | 5 |
|
| Appearance and Characteristics |
| Crystal Structure | cubic body centered |
| Characteristics | soft |
| Color | silvery-white |
| Uses | stainless steels, magnets |
| Hardness | mohs |
| Toxicity | None |
|
| Reactions |
| Reaction with Air | none, w/ht =>Nb2O3 |
| Reaction with 6M HCl | None |
| Reaction with 15M HNO3 | None |
| Reaction with 6M NaOH | None |
|
| Other Forms |
| Number of Isotopes | 1 |
| Hydride | NbH NbH2 |
| Oxide | NbO NbO2 Nb2O5 |
| Chloride | NbCl3 NbCl4 NbCl5 |
|
| Radius |
| Atomic Radius | 146 pm |
| Ionic Radius (1+ ion) | Nil |
| Ionic Radius (1- ion) | Nil |
| Ionic Radius (2+ ion) | Nil |
| Ionic Radius (2- ion) | Nil |
| Ionic Radius (3+ ion) | 86 pm |
|
| Conductivity |
| Thermal Conductivity | 53.7 J/m-sec-deg |
| Electrical Conductivity | 80 1/mohm-cm |
| Polarizability | 15.7 A3 |
|
| Abundance |
| Source | columbite (oxide) |
| Relation Abundance Solar System | -0.156 log |
| Abundance Earth's Crust | 1.3 log |
|
