Noble gas Noble gas The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a group of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six noble gases that occur naturally are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). These elements are all nonmetals. Oganesson (Og) is variously predicted to be a noble gas as well or to break the trend due to relativistic effects; its chemistry has not yet been investigated. For the first six
Trace gas causes its strong absorption of infrared radiation. Below is a table of some of the major greenhouse gases with man-made sources and their contribution to the enhanced greenhouse effect. Key Greenhouse Gases and Sources In contrast, the most abundant gases in the atmosphere are not greenhouse gases. The main reasons is because they cannot absorb infrared radiation as they do not have vibrations with a dipole moment. For instance, the triple bonds of atmospheric dinitrogen make for a highly symmetric molecule that is very inert in the atmosphere. The residence time of a trace gas depends on the abundance and