neon, argon, nitrogen are all possible answers.
carbon
argon (Ar)
argon
neon
inert gas
An inert noble gas is used inside light bulbs.
Argon
tungsten (or wolfram(W)) is usually used as the metal in domestic lighbulbs. The element used as the gas in domestic lightbulbs is usually argon (Ar). Hope this helps :)
It is not a gas, but a vacuum. This keeps the element (wire) from burning up. No oxygen means it can stay hot longer.
Argon or dry nitrogen are common fill gasses in high wattage bulbs. But low wattage bulbs are just vacuum with no fill.
Neon, argon,
Usally Agron