Final answer:
Spectral lines in the solar spectrum, known as Fraunhofer lines, result from absorption of certain wavelengths by the Sun's gases, leading to dark lines in the spectrum.
Step-by-step explanation:
Spectral lines observed in the solar spectrum are due to the absorption of specific wavelengths of light by the atoms in the Sun's gas exterior. The dark lines on the spectrum, known as Fraunhofer lines, are created when atoms at the solar surface absorb energetic photons originating from the interior, and these photons are then re-emitted in directions away from the observer's line of sight. This process leads to certain wavelengths being missing from the continuous spectrum, appearing as black lines. Each chemical element has a characteristic absorption spectrum, meaning it only absorbs radiation at specific wavelengths, which coincide with the emission spectrum wavelengths for that element.