Wolfram

74
W
Gruppe
6
Periode
6
Blok
d
Protoner
Elektroner
Neutroner
74
74
110
Generelle Egenskaber
Atomnummer
74
Atommasse
183,84
Masseantal
184
Kategori
Overgangsmetaller
Farve
Grå
Radioaktiv
Nej
From Swedish, tung sten meaning heavy stone
Krystalstruktur
Rumcentreret Kubisk
Historie
Torbern Bergman obtained from scheelite an oxide of a new element in 1781.

In 1783, José and Fausto Elhuyar found an acid made from wolframite that was identical to tungstic acid.

Later that year, in Spain, the brothers succeeded in isolating tungsten by reduction of this acid with charcoal, and they are credited with the discovery of the element.
Elektroner i hver skal
2, 8, 18, 32, 12, 2
Elektronkonfiguration
[Xe] 4f14 5d4 6s2
W
The chemical symbol, W, comes from the original name of the element, Wolfram
Fysiske Egenskaber
Tilstandsform
Fast stof
Massefylde
19,25 g/cm3
Smeltepunkt
3695,15 K | 3422 °C | 6191,6 °F
Kogepunkt
5828,15 K | 5555 °C | 10031 °F
Smeltevarme
35 kJ/mol
Fordampningsvarme
800 kJ/mol
Varmefylde
0,132 J/g·K
Forekomst i jordskorpen
0,00011%
Forekomst i universet
5×10-8%
Tungsten
Billede akkrediteringer: Images-of-elements
Tungsten rod with oxidized surface
CAS-nummer
7440-33-7
PubChem CID-nummer
23964
Atomare egenskaber
Atomradius
139 pm
Kovalent radius
162 pm
Elektronegativitet
2,36 (Paulings skala)
Ioniseringspotentiale
7,864 eV
Atomvolumen
9,53 cm3/mol
Varmeledningsevne
1,74 W/cm·K
Oxidationstrin
-2, -1, 1, 2, 3, 4, 5, 6
Anvendelser
Tungsten and its alloys are widely used for filaments in electric bulbs and electronic tubes.

Tungsten carbide is of great importance to the metal-working, mining, and petroleum industries.

Tungsten oxides are used in ceramic glazes and calcium/magnesium tungstates are used widely in fluorescent lighting.
Tungsten is considered to be of low toxicity
Isotoper
Stabile isotoper
180W, 182W, 183W, 184W, 186W
Ustabile isotoper
158W, 159W, 160W, 161W, 162W, 163W, 164W, 165W, 166W, 167W, 168W, 169W, 170W, 171W, 172W, 173W, 174W, 175W, 176W, 177W, 178W, 179W, 181W, 185W, 187W, 188W, 189W, 190W, 191W, 192W