Hafnium

72
Hf
Gruppe
4
Periode
6
Block
d
Protonen
Elektronen
Neutronen
72
72
106
Generelle Eigenschaften
Ordnungszahl
72
Atommasse
178,49
Massenzahl
178
Kategorie
Übergangsmetalle
Farbe
Grau
Radioaktiv
Nein
Von Hafinia, dem Lateinischen Namen für Kopenhagen
Kristallstruktur
Einfach hexagonal
Geschichte
In 1911, Georges Urbain claimed to have found the element in rare-earth residues which was shown later to be a mixture of already discovered lanthanides.

Dirk Coster and George de Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon in 1922.

Anton Eduard van Arkel and Jan Hendrik de Boer were the first to prepare metallic hafnium by passing hafnium tetra-iodide vapor over a heated tungsten filament in 1924.
Elektronen pro Schale
2, 8, 18, 32, 10, 2
Elektronenkonfiguration
[Xe] 4f14 5d2 6s2
Hf
In powdered form, hafnium is pyrophoric and can ignite spontaneously in air
Physikalische Eigenschaften
Aggregatzustand
Fest
Dichte
13,31 g/cm3
Schmelzpunkt
2506,15 K | 2233 °C | 4051,4 °F
Siedepunkt
4876,15 K | 4603 °C | 8317,4 °F
Schmelzwärme
25,5 kJ/mol
Verdampfungswärme
630 kJ/mol
Spezifische Wärmekapazität
0,144 J/g·K
Häufigkeit in der Erdkruste
0,00033%
Häufigkeit im Universum
7×10-8%
Electrolytic
Danksagungen für Bilder: Images-of-elements
Electrolytic hafnium
CAS-Nummer
7440-58-6
PubChem CID Number
23986
Atomeigenschaften
Atomradius
159 pm
Kovalenter Radius
175 pm
Elektronegativität
1,3 (Pauling-Skala)
Ionisierungsenergie
6,8251 eV
Molares Volumen
13,6 cm3/mol
Wärmeleitfähigkeit
0,23 W/cm·K
Oxidationszustände
2, 3, 4
Anwendung
Hafnium oxide-based compounds are being introduced into silicon-based chips to produce smaller, more energy efficient and performance packed processors.

Most of the hafnium produced is used in the production of control rods for nuclear reactors.

Hafnium is also used in photographic flash bulbs, light bulb filaments, and in electronic equipment as cathodes and capacitors.
Hafnium is considered to be non-toxic
Isotope
Stabile Isotope
176Hf, 177Hf, 178Hf, 179Hf, 180Hf
Instabile Isotope
153Hf, 154Hf, 155Hf, 156Hf, 157Hf, 158Hf, 159Hf, 160Hf, 161Hf, 162Hf, 163Hf, 164Hf, 165Hf, 166Hf, 167Hf, 168Hf, 169Hf, 170Hf, 171Hf, 172Hf, 173Hf, 174Hf, 175Hf, 181Hf, 182Hf, 183Hf, 184Hf, 185Hf, 186Hf, 187Hf, 188Hf