Tungsten atoms evaporating from the filament can be bounced back to the filament by gas atoms. The filament can be operated at a higher temperature with a fill gas than with a vacuum. ... If this is not offset by the advantage of operating the filament at a higher temperature, then the bulb is more efficient with a vacuum...
An ordinary light bulb contains an inert gas (such as argon or krypton) and nitrogen, which keep the tungsten filament from oxidizing (i.e. burning up). ... The compound then floats around inside the bulb until it hits the hot filament, whereupon the high temperature breaks it down into iodine vapour and metallic tungsten.
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Tungsten atoms evaporating from the filament can be bounced back to the filament by gas atoms. The filament can be operated at a higher temperature with a fill gas than with a vacuum. ... If this is not offset by the advantage of operating the filament at a higher temperature, then the bulb is more efficient with a vacuum...
An ordinary light bulb contains an inert gas (such as argon or krypton) and nitrogen, which keep the tungsten filament from oxidizing (i.e. burning up). ... The compound then floats around inside the bulb until it hits the hot filament, whereupon the high temperature breaks it down into iodine vapour and metallic tungsten.