The term 'A Colorless and Odorless Inert Gas' can be represented by five different solutions: ARGON (5 letters), XENON (5 letters), NEON (4 letters), Ethane (6 letters) and RADON (5 letters). ARGON is a noble gas that is the third most abundant gas in Earth's atmosphere, making up 0.934% of the atmosphere. XENON is also a noble gas that is found in trace amounts in Earth's atmosphere. NEON is a colorless, odorless, inert gas that is the second most abundant noble gas in Earth's atmosphere. Ethane is a hydrocarbon gas that is composed of two carbon atoms and six hydrogen atoms. RADON is a radioactive, colorless, odorless, inert gas that is formed from the decay of uranium and thorium.