Argon

Argon (ˈɑrɡɒn) is a chemical element designated by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table (noble gases). Thanks to recent terraforming efforts, argon is present in the Mar's atmosphere at 0.43%. On Mars, it is the most abundant and most frequently used of the noble gases. Argon's full outer shell makes it stable and resistant to bonding with other elements. Its triple point temperature of 83.8058 K is a defining fixed point in the International Temperature Scale of 1990.

Characteristics

Argon has approximately the same solubility in water as oxygen gas and is 2.5 times more soluble in water than nitrogen gas. Argon is colorless, odorless, tasteless and nontoxic in both its liquid and gaseous forms. Argon is inert under most conditions and forms no confirmed stable compounds at room temperature.

Although argon is a noble gas, it has been found to have the capability of forming some compounds. For example, the creation of argon fluorohydride (HArF), a metastable compound of argon with flourine and hydrogen, was reported by researchers at the University of Helsinki in 2000. Although the neutral ground-state chemical compounds of argon are presently limited to HArF, argon can form clathrates with water when atoms of it are trapped in a lattice of the water molecules. Also argon-containing ions and excited state complexes, such as ArH+ and ArF, respectively, are known to exist. Theoretical calculations have shown several argon compounds that should be stable but for which no synthesis routes are currently known.

Value

The base value of each unit of Argon ranges between 1 and 15 Ð per unit, with up to 4 units being found at any one time.

Presence on Mars: Rare