A lump of gray shining crystals with hexagonal facetting |
عمومي خواص |
---|
Pronunciation | /naɪˈoʊbiəm/ ny-OH-bee-əm |
---|
Alternative name | columbium |
---|
Appearance | gray metallic, bluish when oxidized |
---|
|
Niobium پهدوراني جدول کې |
---|
|
اټومي شمیره(Z) | 41 |
---|
گروپ,پیریود | group 5,period 5 |
---|
بلاک | d-block |
---|
Element category | transition metal |
---|
معياري اټومي وزن (Ar) | کينډۍ:Val[۱] |
---|
Electron configuration | [Kr] 4d4 5s1 |
---|
Electrons per shell | 2, 8, 18, 12, 1 |
---|
فزیکي خواص |
---|
حالت(at STP) | جامد |
---|
دويلې کيدو ټکى | 2750 K (2477 °C, 4491 °F) |
---|
يشنا ټکی | 5017 K (4744 °C, 8571 °F) |
---|
Density near r.t. | 8.57 g/cm3 |
---|
Heat of fusion | 30 kJ/mol |
---|
Heat of vaporization | 689.9 kJ/mol |
---|
Molar heat capacity | 24.60 J/(mol·K) |
---|
Vapor pressureP (Pa) | 1 | 10 | 100 | 1 k | 10 k | 100 k |
---|
at T (K) | 2942 | 3207 | 3524 | 3910 | 4393 | 5013 |
---|
|
اټومي خواص |
---|
Oxidation states | 5, 4, 3, 2, 1, −1, −3 (a mildlyacidic oxide) |
---|
Electronegativity | Pauling scale: 1.6 |
---|
Ionization energies | - 1st: 652.1 kJ/mol
- 2nd: 1380 kJ/mol
- 3rd: 2416 kJ/mol
-
|
---|
Atomic radius | empirical: 146 pm |
---|
Covalent radius | 164±6 pm |
---|
Miscellanea |
---|
Crystal structure | body-centered cubic (bcc) Cubic body-centered crystal structure for niobium |
---|
Speed of sound thin rod | 3480 m/s (at 20 °C) |
---|
Thermal expansion | 7.3 µm/(m·K) |
---|
د تودوخې تېرېدنه | 53.7 W/(m·K) |
---|
Electrical resistivity | 152 nΩ·m (at 0 °C) |
---|
Magnetic ordering | paramagnetic |
---|
Young's modulus | 105 GPa |
---|
Shear modulus | 38 GPa |
---|
Bulk modulus | 170 GPa |
---|
Poisson ratio | 0.40 |
---|
Mohs hardness | 6.0 |
---|
Vickers hardness | 870–1320 MPa |
---|
Brinell hardness | 735–2450 MPa |
---|
CAS Number | 7440-03-1 |
---|
History |
---|
Naming | afterNiobe in Greek mythology, daughter ofTantalus (tantalum) |
---|
Discovery | Charles Hatchett (1801) |
---|
First isolation | Christian Wilhelm Blomstrand (1864) |
---|
Recognized as a distinctelement by | Heinrich Rose (1844) |
---|
Mainisotopes of niobium |
---|
|
| references | in Wikidata |