What does the nitrogen inside a light bulb do?

Answer 1

Yes, modern incandescent bulbs are filled with an inert gas (argon,) but with a bit of nitrogen. Nitrogen is used because argon supports long sparks and leads to electric arcs and exploding light bulbs, and nitrogen interferes with this effect.

Answer 2

Modern light bulbs don't hold a vacuum. Instead they are filled with an inert (electrically non-conducting) gas such as Nitrogen. An inert gas is used to fill the bulb (instead of just pumping out almost all the ordinary air to leave a near-vacuum) because the action of filling the bulb with an inert gas flushes away ALL of the ordinary air. In addition the inert gas has the very useful physical property of helping to conduct heat from the glowing filament to the glass bulb. This allows the whole surface area of the glass bulb to radiate heat into the surrounding air. It is important to understand that the inert gas does not allow the filament to "burn away" as it would if some air were still present in the bulb. This sometimes happens if a light bulb gets knocked and gets even a tiny crack in its glass bulb: the oxygen present in ordinary air will quickly make the filament burn away. So, to summarize, the inert gas which is used to fill the glass bulb allows the filament to glow very brightly without burning and conducts the heat produced by the filament away to the glass bulb.

Answer 3

Incandescent bulbs can use Argon or Krypton, which are inert. These gasses help slow down the decay of the tungsten filament. Halogen bulbs use a halogen (column 17 element) such as iodine to react with the hot tungsten atoms and allow the filament last longer.

Neon lights use neon gas. Xenon gas is used in strobe lights. These are also inert gasses.

Fluorescent bulbs typically use Mercury vapor.