The filament glows in liquid nitrogen.
name: The bubble of inert nitrogen prevents the wolfram wire from burning.
Mad Scientist, David Willey, makes a liquid nitrogen light bulb.
Wear eye protection goggles and gloves. Use extreme care when handling liquid nitrogen.
Always follow general safety
recommendations. Please note that conducting chemistry
experiments you must comply with the relevant legal procedures in
- Prepare two light bulbs. Make sure that they are functioning properly.
- Break the glass covering.
- Screw one of the broken light bulbs into the lamp socket. The filament burns immediately when power is turned on.
- Fill a large glass beaker with liquid nitrogen.
- Screw the other light bulb into the lamp socket and place it into the liquid nitrogen.
- When power is turned on the filament glows with a bright light.
To understand what happens in this experiment lets first consider the setup of a common light bulb. The main part of the light bulb is the filament. The filament represents a wolfram wire which poses a high electricity resistance. When electric current flows through the filament it makes it so hot that it starts glowing. This is a really high temperature of about 3000 °C! If there is some oxygen in the surrounding area, it burns the filament. That is why the wire needs to be insulated from atmosphere air. For this purpose the filament is placed into a glass enclosure filled with an inert gas or into the glass enclosure from which all air was pumped out. By Removing the glass enclosure in the experiment we make the wire unprotected to oxygen action. When the power turns on the filament quickly burns. The beaker with liquid nitrogen works as a bulb with inert atmosphere. The glowing hot wire evaporates liquid nitrogen around itself but does not react with it. Nitrogen does not participate in the chemical reactions except for a few cases. It is very inert due to the strong triple bond between two nitrogen atoms which form the nitrogen molecule.