NO. 018Noble Gas
Ar
Argon
Argon is a noble gas that makes up nearly one percent of Earth’s atmosphere. It is chemically inert and commonly used as a shielding gas in welding and manufacturing processes. Argon is also used in lighting and preserving sensitive materials.
Technical Specifications
Atomic Mass39.948 u
Density0.001784 g/cm³
Melting Point83.8 K
Boiling Point87.3 K
Atomic Radius71 pm
Electronegativity0
Ionization Energy1521 kJ/mol
Electron Affinity0 kJ/mol
Bonding TypeCovalent
Oxidation States0
Acid/BaseNeutral
ReactivityLow
Electron Configuration
[Ne] 3s2 3p6
Discovered ByLord Rayleigh
Year1894
Known Isotopes
Argon-36Argon-38Argon-40