What is Argon?

Argon is a chemical element with the symbol Ar and atomic number 18. It is a noble gas, making it largely inert. It is used in lighting (e.g., in fluorescent and incandescent bulbs to prevent oxidation of the filament), welding (as a shielding gas to prevent oxidation), and in various industrial applications where an inert atmosphere is needed. It is also used in some medical procedures and for preserving documents.