Argon

18
Ar
Gruppe
18
Periode
3
Blok
p
Protons
Electrons
Neutrons
18
18
22
General Properties
Atomnummer
18
Atommasse
39,948
Mass Number
40
Kategori
Ædelgasser
Farve
Colorless
Radioactive
Nej
From the Greek argos, inactive
Krystalstruktur
Fladecentreret Kubisk
History
Argon was suspected to be present in air by Henry Cavendish in 1785.

It was not isolated until 1894 by Lord Rayleigh and Sir William Ramsay in Scotland.

Argon became the first member of the noble gases to be discovered.

In 1957, IUPAC agreed that the symbol should change from A to Ar.
Elektroner i hver skal
2, 8, 8
Elektronkonfiguration
[Ne] 3s2 3p6
Ar
Argon makes a distinctive blue-green gas laser
Physical Properties
Tilstandsform
Gas
Massefylde
0,0017837 g/cm3
Smeltepunkt
83,8 K | -189,35 °C | -308,83 °F
Kogepunkt
87,3 K | -185,85 °C | -302,53 °F
Smeltevarme
1,18 kJ/mol
Fordampningsvarme
6,5 kJ/mol
Varmefylde
0,52 J/g·K
Abundance in Earth's crust
0,00015%
Abundance in Universe
0,02%
Vial
Billede akkrediteringer: Images-of-elements
Vial of glowing ultrapure argon
CAS Number
7440-37-1
PubChem CID Number
23968
Atomic Properties
Atomradius
71 pm
Kovalent radius
106 pm
Elektronegativitet
-
Ionization Potential
15,7596 eV
Atomic Volume
22,4 cm3/mol
Varmeledningsevne
0,0001772 W/cm·K
Oxidationstrin
0
Applications
Argon gas is used to fill conventional incandescent and fluorescent light bulbs.

Argon is also used as an inert gas shield for arc welding and cutting, as blanket for the production of titanium and other reactive elements.

It is used as a protective atmosphere for growing silicon and germanium crystals.
Argon is considered to be non-toxic
Isotoper
Stable Isotopes
36Ar, 38Ar, 40Ar
Unstable Isotopes
30Ar, 31Ar, 32Ar, 33Ar, 34Ar, 35Ar, 37Ar, 39Ar, 41Ar, 42Ar, 43Ar, 44Ar, 45Ar, 46Ar, 47Ar, 48Ar, 49Ar, 50Ar, 51Ar, 52Ar, 53Ar