How is oxygen considered an inert gas?

Oxygen, on the other hand, reacts with most of the metals to form their oxides and other compounds. Sometimes it reacts even at room temperature in case of alkali metals like sodium, potassium and others. So oxygen is a very reactive gas and cannot be considered inert. read more

Unlike noble gases, an inert gas is not necessarily elemental and is often a compound gas. Like the noble gases the tendency for non-reactivity is due to the valence, the outermost electron shell, being complete in all the inert gases. read more

Oxygen is not a noble gas. Oxygen is a gas in the group 6 of the periodic table which needs 2 more electrons to complete the outermost shell. Noble gases also called inert gases on the other hand have their outermost shell completed and they are listed last on the right hand side of the periodic table. read more