What is the empirical distinction between emission and absorption spectra? In general terms, how did Niels Bohr explain each of these spectra?
In general terms, emission spectra are obtained when the electron is at a high energy level and it falls to a lower energy level. In absorption, the electron is at a lower level, absorbs energy, and is raised to a higher level. As to how Niels bohr explained all of this, I refer you to your text. Look at the Balmer series (and other series) and how Bohr explained that.
The empirical distinction between emission and absorption spectra can be understood based on the behavior of electrons in atoms.
In simple terms, emission spectra are obtained when the electrons in an atom transition from higher energy levels to lower energy levels, releasing energy in the form of electromagnetic radiation. This emitted light is called an emission spectrum and appears as a series of distinct lines or bands of colors. Each element has a unique emission spectrum.
On the other hand, absorption spectra are observed when atoms absorb electromagnetic radiation and the energy of electrons increases, causing transitions to higher energy levels. This absorption of light results in the absence of certain colors or wavelengths in the transmitted or reflected light, producing a characteristic absorption spectrum.
Niels Bohr's model of the atom, proposed in 1913, provided an explanation for these spectra. According to Bohr's model, electrons move in specific energy levels or orbits around the atomic nucleus. Electrons can transition between these energy levels by either absorbing or emitting specific amounts of energy.
Bohr explained the spectral lines observed in the hydrogen atom using his model. He postulated that electrons could only exist in certain discrete energy levels, and the differences in energy between these levels corresponded to specific wavelengths of light. The Balmer series, for instance, describes the visible emission lines in the hydrogen atom, and Bohr's model successfully predicted and explained their positions in the spectrum.
However, it is important to note that Bohr's model is a simplified representation of atomic behavior and has been expanded upon and refined by subsequent advancements in quantum mechanics. Therefore, for a comprehensive understanding of the topic, further research and study of the specific details of Bohr's model and its limitations are recommended.