Question

If the hydrogen in a hydrogen lamp was molecular hydrogen (H2) rather than atomic (H), what would the main differences in the observed spectrum be?

This question was asked in the context of an experiment using a spectrometer and diffraction grating to determine the wavelengths of four visible lines of the hydrogen emission spectrum. (May not be relevant to the question)

Answer 1

The spectral series of hydrogen actually lies within visible light, so no matter if `H_2` or `H` is used, you will always see four visible light spectra.

Explanation:

This technique is actually used in astronomy to identify stars and other celestial objects as a reference when calculating redshift or blueshift.
I hope this answers your question!