sentence: Filament is made up mostly of tungsten, a type of metal.
sentences_before: The incandescent light bulb turns electricity into light by sending the electric current through a thin wire called a filament.
sentences_after: The resistance of the filament heats the bulb up. Eventually the filament gets so hot that it glows, producing light.
concept_name: filament
headings: Lightbulb Types Incandescent
categories: Light sources Machines Home appliances