Hafnium

72
Hf
Skupina
4
Perioda
6
Blok
d
Protony
Electrons
Neutrony
72
72
106
Hlavní vlastnosti
Atomové číslo
72
Atomová hmotnost
178,49
Mass Number
178
Kategorie
Přechodné kovy
Barva
Šedá
Radioaktivní
Ne
From Hafinia, the Latin name for Copenhagen
Krystalografická soustava
Hexagonální
Historie
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.
Elektronů v obalu
2, 8, 18, 32, 10, 2
Elektronová konfigurace
[Xe] 4f14 5d2 6s2
Hf
In powdered form, hafnium is pyrophoric and can ignite spontaneously in air
Fyzické vlastnosti
Skupenství
Pevná
Hustota
13,31 g/cm3
Teplota tání
2506,15 K | 2233 °C | 4051,4 °F
Teplota varu
4876,15 K | 4603 °C | 8317,4 °F
Skupenské teplo tání
25,5 kJ/mol
Skupenské teplo varu
630 kJ/mol
Měrná tepelná kapacita
0,144 J/g·K
Hojnost v zemské kůře
0,00033%
Hojnost ve vesmíru
7×10-8%
Electrolytic
Autorská práva obrázku: Images-of-elements
Electrolytic hafnium
CAS Number
7440-58-6
PubChem CID Number
23986
Atomové vlastnosti
Atomový poloměr
159 pm
Kovalentní poloměr
175 pm
Elektronegativita
1,3 (Paulingova stupnice)
Ionizační potenciál
6,8251 eV
Molární objem
13,6 cm3/mol
Tepelná vodivost
0,23 W/cm·K
Oxidační čísla
2, 3, 4
Aplikace
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
Izotopy
Stabilní izotopy
176Hf, 177Hf, 178Hf, 179Hf, 180Hf
Nestabilní izotopy
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