Argon is the third noble gas, in period 8, and it makes up about 1% of the Earth's atmosphere. Argon has approximately the same solubility as oxygen and it is 2.5 times as soluble in water as nitrogen . This chemically inert element is colorless and odorless in both its liquid and gaseous forms.
the chemical element of atomic number 18, an inert gaseous element of the noble gas group. Argon is the most common noble gas, making up nearly one percent of the earth's atmosphere.