Symbol

Ar

Atomic Number

18

Atomic Mass

39.948

Family

Group 18 (Viiia) Noble Gas Pronunciation

AR-gon

Overview

Argon is a noble gas. The noble gases are the six elements in Group 18 (VIIIA) of the periodic table. The periodic table is a chart that shows how the chemical elements are related to each other. The noble gases are sometimes called inert gases because Group 18 (VIIIA) elements react with very few other elements. In fact, no compound of argon has ever been produced.

Argon was discovered in 1894 by English chemist John William Strutt, most commonly known as Lord Rayleigh (1842-1919), and Scottish chemist William Ramsay (1852-1916). It was the first of the noble gases to be isolated.

Rayleigh and Ramsay discovered argon by the fractional distillation of liquid air. Fractional distillation is the process of letting liquid air slowly warm up. As the air warms, different elements change from a liquid back to...