Why are nitrogen and argon used in electric bulbs?

You can't fill a bulb with air or hot tungsten wire will combust in presence of oxygen. You can't maintain vacuum either or external atmospheric pressure will break the glass. So, u hav to fill it with non-reactive gas like nitrogen. While nitrogen does react with hydrogen to form ammonia, the process is very difficult. read more

Argon is an inert gas and used to extend the life of the filament. The glass bulb is evacuated prior to the introduction of the argon but the evacuation process is not absolute and oxygen atoms remain, though much fewer of them. read more

Your choices are an inert gas like nitrogen or argon that won’t react with the hot filament, or a vacuum. Any oxygen would react quickly with the tungsten causing a burnout. read more

The only solution to these problems is an inert gas. The inert gas within the bulb will maintain a particular pressure, preventing the filament from evaporating. An obviously, inert gas won’t react with the filament. Nitrogen is also used like argon since it is unreactive. read more