Passage I (Questions 1-8)
The figure below shows a photograph obtained when light from a low-pressure hydrogen lamp is passed through a spectrometer.
Two scientists offer their views on the interpretation of these lines.
Scientist 1: These "spectral lines" point to the existence of quantized energy levels in the hydrogen atom. The lines at different wavelengths represent photons after an electron has been promoted to a higher level in the atom, and then relaxed down to either the ground state or a low-lying excited state.
By converting the wavelengths to energies, we can construct the following diagram showing the energy levels that must exist in the atom:
Scientist 2: My colleague has missed an important alternative explanation, which I am certain is the correct one. Hydrogen does not have discrete energy levels; rather, the glass in the spectrometer used to measure the wavelength has peculiar gaps in its transmission properties--it only allows certain colors through.