Answer:
Definition of spectral line: one of a series of linear images formed by a spectrograph or similar instrument and corresponding to a narrow portion of the spectrum of the radiation emitted or absorbed by a particular source.
Definition of Wavelength: can be defined as the distance between two successive crests or troughs of a wave. It is measured in the direction of the wave. ... Wavelength is inversely proportional to frequency. This means the longer the wavelength, lower the frequency.
So, the spectrum is the range of wavelength in visible light. While, wavelength is the length of a wave.
Explanation:
I hope this helps!
