Krypton Light Bulbs
All the light bulbs in this category use krypton and/or xenon as part or all of the gas fill. Most standard incandescent light bulbs are filled with inert argon plus enough nitrogen to suppress arcing between the lead-in wires. Krypton and xenon gas contribute two features that improve the efficacy (or efficiency) of the lamp compared to ones filled with argon. Firstly, both gases have a lower heat conductivity than argon. Secondly, the larger molecule size of both gases retards the evaporation of the tungsten filament and increases bulb life. Xenon is an improvement over krypton for both factors.