Answer:
*if a hydrogen emission line is observed in the galaxy, this implies that the galaxy has a significant amount of a chemical element
*difference between the two wavelengths e can be explained by the relativistic Doppler effect
Explanation:
The emission of the materials depends on the distribution of the electrons around the atoms and their possible transitions. These emissions are maintained even when the element is mixed in some compound.
Consequently, if a hydrogen emission line is observed in the galaxy, this implies that the galaxy has a significant amount of a chemical element.
The small difference between the two wavelengths e can be explained by the relativistic Doppler effect, due to the movement of the galaxy
