The term 'Noble Gas in the Atmosphere' refers to a group of gases that are found in Earth's atmosphere. One of these gases is ARGON, which has five letters. ARGON is an odorless, colorless, and non-flammable gas that makes up approximately 1% of the Earth's atmosphere. It is the third most abundant gas in the atmosphere, after nitrogen and oxygen. ARGON is used in a variety of industrial applications, including welding, lighting, and refrigeration.