Final answer:
For an efficient emission of visible light when a filament becomes very hot, a white tungsten filament is the best choice due to its broad frequency emission spectrum and higher visibility.
Step-by-step explanation:
If you are choosing the filament for a light bulb and want it to emit visible light as efficiently as possible when it becomes very hot, white would be the best choice. The filament in electric light bulbs is typically made of tungsten because when tungsten filaments are heated, they emit a light that contains virtually every frequency. This breadth of emitted frequencies means that the resultant light is perceived as white, which is the most efficient for human usage because it appears the brightest to our eyes and has the greatest practical application.
The efficiency of a light bulb is often determined by the ratio of light output within the visible spectrum compared to the total light emitted. It's important to note that no thermal source can reach 100% efficiency due to the emission of some non-visible wavelengths at any given temperature. As the temperature increases, the emitted light shifts to shorter wavelengths, which means higher frequency and energy. A bright tungsten filament efficiently reaches the desired visible light spectrum at a high temperature without undergoing rapid evaporation or combustion, thanks to its robust physical properties.