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Vanadium (V), Niobium (Nb) and tantalum (Ta) are important metals that are not
all that rare. |
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Tantalum has been seen as critical since it was linked to the ongoing
war in the Congo, a source of the mineral group known as "coltan". Wrongly, tantalum was and is described as crucial
for silicon microchip technology. It is actually important for so-called tantalum (or better tantalum oxide) capacitors,
which are indeed crucial for electronics but not relalted to silicon technology. |
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Vanadium, Niob und Tantal sind wichtige und realtiv häufig vorkommende Elemente; Hahnium
ist künstlich erzeugt. Alle Elemente sind technisch wichtig ("Tantalkondensator), insbesondere als Legierungsbestandteile.
Nb war (und wahrscheinlich ist) ein Hauptbestandteil von technisch eingesetzten Supraleitern. |
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Niobium and vanadium are improtant alloy elements for steel. Vanadium is also held responsible for the
"water pattern" in wooth steel. |
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Table of Basic Data |
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Name
(German) |
Vandium
Vandium
| Niob
Niobium |
Tantal
Tantalum
| | Atomic number |
23 | 41 | 73 |
| Atomic mass [u ] |
50,9415 | 92,90638 |
180,9479 | | Melting point [K] |
2163 | 2741 |
3269 |
| Melting point [oC] | 1890 |
2468 | 2996 |
| Melting point [oF] | 3434 |
4474 | 5425
|
| Boiling point [K] | 3653 |
5200 | 5698 |
| Density [g/cm3] | 6,09 |
8,58 | 16,68 |
| Ionization energy [eV] | 6,74 |
6,88 | 7,89 |
| Electro-negativitiy | 1,5 |
1,2 | 1,4 |
| Atomic radius [pm] | 132,1 |
142,9 | 143 |
| Ionic radius [pm] | 59 |
69 | 64 |
| Oxidation numbers | 5 bis -3 |
5 bis -1 | 5 bis -1 |
Lattice typ
Transformation temp. [oC] |
bcc
- | bcc
- |
bcc
- |
Therm. expansion coefficient a
Lattice constant [Å]
(a or c) | 3,03 |
3,30 | 3,30 |
| Young's - Modul us [GPa] | 127 |
104 | 175 |
| [10-6K-1] | 7,8 |
7,1 | 3,6 |
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In case of doubt all numbers are for room temperatures |
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fcc = face centered
cubic; lattice const. = a
bcc = body centered
cubic
sc = simple cubic
hp = simple hexagonal
hcp = hexagonal close packed; lattice constants a and
c.
op = simple orthorhombic, monoclinic, triclinic
tp = simple tetragonal
dia = diamond structure
r = trigonal or rhomboedral trigonal |
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© H. Föll (Iron, Steel and Swords script)
With frame
Glossary