What type of spectrum does a solid object produce when heated?

When a solid object is heated, it emits light across a broad range of wavelengths, resulting in a continuous spectrum. This phenomenon occurs because the heated solid can vibrate and emit photons of various energies, producing a smooth gradient of colors without any gaps.

The continuous spectrum typically features a blend of colors from red to violet, reflecting the thermal radiation emitted by the heated object, commonly described by Planck's law. When the object reaches higher temperatures, it may also produce more light in the blue and ultraviolet part of the spectrum, demonstrating the relationship between temperature and the peak wavelength of emitted light, as shown by Wien's displacement law.

In contrast, an emission spectrum results from hot gases emitting specific wavelengths of light, an absorption spectrum comes from light passing through a cooler gas and being absorbed at specific wavelengths, and a line spectrum is seen in gases under certain conditions when distinct lines indicate the presence of specific elements. These latter types are characterized by discrete lines rather than the smooth output found in a continuous spectrum, highlighting the unique nature of light produced by solid objects when heated.