Argon (Ar)

Physical properties

Phase at STP Gas
Melting point    83.81 K ​(−189.34 °C, ​−308.81 °F)
Boiling point    87.302 K ​(−185.848 °C, ​−302.526 °F)
Density    1.784 g/L (when liquid) ,  1.3954 g/cm3) (when at boiling point)

Other:
Triple point  =  83.8058 K, ​68.89 kPa
Critical point  =  150.687 K, 4.863 MPa
Heat of fusion  =  1.18 kJ/mol
Heat of vaporization =   6.53 kJ/mol
Molar heat capacity  =  20.85 J/(mol·K)
In dry air on Earth, by volume argon occupies = 0.97%