Argon gas is a colorless, odorless, and tasteless noble gas that makes up about 0.93% of the Earth's atmosphere. It is chemically inert, meaning it does not easily react with other elements, which makes it useful in various applications, such as welding and lighting. Argon is often used to create an inert atmosphere for processes that require protection from air. Discovered in 1894 by Lord Rayleigh and William Ramsay, argon is the third most abundant gas in the atmosphere after nitrogen and oxygen. It is commonly found in fluorescent and incandescent light bulbs, where it helps to prevent the filament from oxidizing.