Symbol: Ar
Atomic Number: 18
Atomic Weight: 39.948
Element Classification: Inert Gas
Discovered By: Sir William Ramsey, Baron Rayleigh
Discovery Date: 1894 (Scotland)
Name Origin: Greek: argos (inactive).
Density (g/cc): 1.40 (@ -186°C)
Melting Point (K): 83.8
Boiling Point (K): 87.3
Appearance: Colorless, tasteless, odorless noble gas
Atomic Radius (pm): 2-
Atomic Volume (cc/mol): 24.2
Covalent Radius (pm): 98
Ionic Radius: n/a
Specific Heat (@20°C J/g mol): 0.138
Fusion Heat (kJ/mol): n/a
Evaporation Heat (kJ/mol): 6.52
Thermal Conductivity (@25°C W/m K):
Debye Temperature (K): 85.00
Pauling Negativity Number: 0.0
First Ionizing Energy (kJ/mol): 1519.6
Oxidation States: n/a
Electronic Configuration: [Ne] 3s² 3p⁶
Lattice Structure: Face-Centered Cubic (FCC)
Lattice Constant (Å): 5.260
Lattice C/A Ratio: n/a