Hafni
72
Hf
Grup
4
Període
6
Bloc
d
Protons
Electrons
Neutrons
72
72
106
Propietats Generals
Nombre atòmic
72
Massa atòmica
178,49
Nombre de massa
178
Categoria
Metalls de transició
Color
Gris
Radioactiu
No
From Hafinia, the Latin name for Copenhagen
Estructura cristal·lina
Hexàgon simple
Història
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.
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.
Electrons per capa
2, 8, 18, 32, 10, 2
Configuració electrònica
[Xe] 4f14 5d2 6s2
In powdered form, hafnium is pyrophoric and can ignite spontaneously in air
Propietats Físiques
Fase
Sòlid
Densitat
13,31 g/cm3
Punt de fusió
2506,15 K | 2233 °C | 4051,4 °F
Punt d'ebullició
4876,15 K | 4603 °C | 8317,4 °F
Entalpia de fusió
25,5 kJ/mol
Entalpia de vaporització
630 kJ/mol
Capacitat tèrmica específica
0,144 J/g·K
Abundància a l'escorça terrestre
0,00033%
Abundància a l'univers
7×10-8%
Número CAS
7440-58-6
Número CID de PubChem
23986
Propietats Atòmiques
Radi atòmic
159 pm
Radi covalent
175 pm
Electronegativitat
1,3 (Escala de Pauling)
Potencial d'ionització
6,8251 eV
Volum atòmic
13,6 cm3/mol
Conductivitat tèrmica
0,23 W/cm·K
Estats d'oxidació
2, 3, 4
Aplicacions
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.
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
Isòtops
Isòtops estables
176Hf, 177Hf, 178Hf, 179Hf, 180HfIsòtops inestables
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