Bulb in Liquid Nitrogen.MOV

Overview:
An envelope of a light bulb is usually filled with argon gas. As the filament heats to ~2000 degrees Celcius, the filament will glow very white in color.
If the envelope is broken and then placed in a beaker of liquid nitrogen, the filament causes liquid nitrogen to boil producing an insulating bubble of nitrogen around the filament. This acts very much like the argon gas that was in the envelope to begin with.

If the filament is in the open air oxygen can get to the filament, which will react to form tungsten oxides and it burns away.

Instructions:
Carefully break the envelope of the light bulb, with special care to keep the filament intacked. Then pour liquid nitrogen into the beaker.

Once the beaker is down to temperature, plung the bulb filament into the beaker and turn on the light. You should see the bulb light up and the liquid nitrogen will begin to boil.

You can either leave the bulb in the liquid nitrogen until it boils away or you can pull the filament out of the liquid nitrogen and within a few seconds, you will see how the filament burns away when in open air.

Category:

Science & Technology

Tags:

• CIMG2628

[TheKaundere]

hey you said watc it explode!

Where is my explosion ?

[UMDemoLab]

@TheKaundere The filament doesn't actually explode, but produces the really bright flame that you see once the filament is removed from the liquid nitrogen.

[jeffddow]

@zaxtor probably longer than a regular lightbulb, considering it keeps it colder as well

[zaxtor]

How long would the filament burn under liquid nitrogen if we keep it cold.

[mbotv10]

It looks very nice! Cool video!