Argon

Argon Element Properties

p17
Cl
Chlorine
p18
Ar
Argon
s19
K
Potassium
General
NameArgon
SymbolAr
Number18
Group Number18
GroupNoble Gas
Blockp
Density0.0017824 g/cm3
Atomic Weight39.948 g/mol
Atomic Volume28.5 cm3/mol
Discover1894


States
StateGas
Melting Point83.80 K
Boiling Point87.30 K
Triple Point83.8058 K
Critical Point150.87 K
Heat of Fusion1.18 kJ/mol
Heat of Vaporization6.43 kJ/mol


Energies
First Ionization Energy1520.5 kJ/mole
Second Ionization Energy2665.8 kJ/mole
Third Ionization Energy3930.8 kJ/mole
ElectronegativityNil
Electron AffinityNil
Specific Heat0.520 J/gK
Heat Atomization0 kJ/mole atoms


Oxidation and Electrons
Shells2,8,8
Electron Configuration[Ne] 3s2 3p6
Minimum Oxidation Number0
Maximum Oxidation Number0
Minimum Common Oxidation Number0
Maximum Common Oxidation Number0


Appearance and Characteristics
Crystal Structurecubic face centered
CharacteristicsInert
Colorcolorless
Useslasers, light bulbs
Hardnessmohs
ToxicityNo


Reactions
Reaction with AirNone
Reaction with 6M HClNone
Reaction with 15M HNO3None
Reaction with 6M NaOHNone


Other Forms
Number of Isotopes3
HydrideNone
OxideNone
ChlorideNone


Radius
Atomic Radius98 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)Nil


Conductivity
Thermal Conductivity0.02 J/m-sec-deg
Electrical Conductivity0 1/mohm-cm
Polarizability1.586 A3


Abundance
SourceAir
Relation Abundance Solar System5.004 log
Abundance Earth's Crust0.5 log


p17
Cl
Chlorine
p18
Ar
Argon
s19
K
Potassium