18 Ar ATOMIC MASS 39.948

ELEMENT 18 · NOBLE GAS

Argon (Ar)

Argon is an inert gas that makes up nearly one percent of Earth's atmosphere and shields materials from reactive air.

Atomic number
18
Category
Noble gas
Period
3
Group
18
State
Gas

Fun facts about Argon

  • Its name reflects its chemical inactivity.
  • Argon is more abundant in air than carbon dioxide.
  • It produces a lilac-violet glow in a discharge tube.

Common uses of Argon

  • Shielding gas for welding
  • Inert lamp filling
  • Protective atmospheres for manufacturing

Where Argon sits in the periodic table

Argon is classified as a noble gas in period 3 and group 18 of the periodic table. Under the conditions represented in this reference, its state is gas.

Quick chemistry revision

For quick revision, pair the symbol Ar with atomic number 18 and the listed atomic mass 39.948. The summary, facts, and uses above keep those element properties together in one reference.