Oxygen

Oxygen (O₂) is a colorless, tasteless, and odorless gas at room temperature and standard atmospheric pressure. It is a chemical element with the atomic number 8 and is highly reactive, forming compounds with almost all other elements except noble gases. Oxygen is essential for respiration in most living organisms and is used in various industrial processes, including combustion, oxidation, and in various chemical syntheses.

Despite its critical role in life and many processes, oxygen itself does not have a discernible scent. Humans cannot detect its presence by smell alone. However, in certain high-concentration environments, such as after a thunderstorm or near an ozone generator, people might perceive a fresh, sharp smell which is actually due to ozone (O₃) and other substances, not oxygen itself. Thus, any "scent" typically attributed to oxygen is usually the result of other chemical substances or the ionization of air, rather than the oxygen.