36 Ar and 38 Ar content may be as high as 2.07% and 4.3% respectively in natural samples. 40 Ar is the remainder in such cases, whose content may be as low as 93.6%.
Argon is a chemical element. Its symbol is argon is Ar and its atomic number is 18. It is part of the noble gas group. It is an odorless and tasteless gas. Argon is the third-most abundant gas in the Earth's atmosphere.
The name "argon" is from the Greek word ἀργός meaning "lazy" or "inactive" because it does not react with other chemicals.