Wolfram

74
W
Gruppe
6
Periode
6
Blok
d
Protons
Electrons
Neutrons
74
74
110
General Properties
Atomnummer
74
Atommasse
183,84
Mass Number
184
Kategori
Overgangsmetaller
Farve
Grå
Radioactive
Nej
From Swedish, tung sten meaning heavy stone
Krystalstruktur
Rumcentreret Kubisk
History
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
Physical Properties
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
Abundance in Earth's crust
0,00011%
Abundance in Universe
5×10-8%
Tungsten
Billede akkrediteringer: Images-of-elements
Tungsten rod with oxidized surface
CAS Number
7440-33-7
PubChem CID Number
23964
Atomic Properties
Atomradius
139 pm
Kovalent radius
162 pm
Elektronegativitet
2,36 (Paulings skala)
Ionization Potential
7,864 eV
Atomic Volume
9,53 cm3/mol
Varmeledningsevne
1,74 W/cm·K
Oxidationstrin
-2, -1, 1, 2, 3, 4, 5, 6
Applications
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
Stable Isotopes
180W, 182W, 183W, 184W, 186W
Unstable Isotopes
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