Argon is a chemical element with symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in the atmosphere of Earth.

Atomic Weight:  39.948
Density:        1.784 g/l
Melting Point:  -189.3 °C
 Boiling Point: -185.8 °C