Name: Argon
Symbol: Ar
Atomic Number: 18
AtomicWeight: 39.948000
Family: noble gases
CAS RN: 7440-37-1
Description: An inert colorless gas
State (25 °C): Gas
Melting Point: 84 °K
Boiling Point: 87 °K
Density: .001784 g/cm³
Oxidation states: 0
Electron Configuration: [Ne] 3s²3p⁶
Radius: 71 pm (Covalent)
Electronegativity: – (Pauling Scale)

1st Ionization Energy: 1521 KJ/mole
2nd Ionization Energy: 2666 KJ/mole
3rd Ionization Energy: 3931 KJ/mole