How do noble gases contribute to air composition?

Noble gases, such as helium, neon, argon, krypton, xenon, and radon, are indeed unreactive due to their completed outer electron shells, which means they do not readily engage in chemical reactions. This inertness is a key characteristic that defines noble gases. In the atmosphere, they contribute to the overall composition of air as a minor component, amounting to about 1% of the volume of the atmosphere, with argon being the most abundant among them.

Their unreactive nature means they do not participate in combustion or other chemical processes that contribute to reactions involving more reactive gases like oxygen and nitrogen. Furthermore, while noble gases are present in the atmosphere, their role does not include enhancing the greenhouse effect or replacing oxygen; instead, they coexist with other gases without interfering chemically. Thus, the information about their composition and characteristics reinforces why they account for a small percentage of the air we breathe.