nuclei. Many of these aspects are ultimately based on the physical interactions
discussed in this chapter.
NMR has found some use in the medical field (see Figure 16.25), where
large nuclear magnetic resonance spectrometers are set up so that people can
be used as samples. A patient is placed in a magnetic field and bombarded with
harmless radio waves. NMR signals from the protons in the tissues can be an-
alyzed. In this way, the status of the bodily tissues can be determined, and with
the computer control that is available, medical doctors can obtain many per-
spectives of the tissues inside a patient without any sort of invasive procedures.
Problems like tumors, spinal irregularities, and cardiovascular disease can be
evaluated without harm to the patient. However, in the medical field the tech-
nique is referred to as magnetic resonance imaging,or MRI. Apparently the
word “nuclear” is dropped because of its connotations. Be that as it may, MRI
is still NMR, a nuclearspin phenomenon.16.6 Summary
Besides those presented here, other types of spectroscopy use magnetic fields
to help differentiate among the wavefunctions of molecules. The three types
discussed here—Zeeman, ESR, and NMR—only scratch the surface. Magnetic
spectroscopy is useful in chemistry in part because of its ability to access indi-
vidual wavefunctions that are normally degenerate. An even closer look, with582 CHAPTER 16 Introduction to Magnetic Spectroscopy
Figure 16.25 NMR is used in the medical field to generate pictures of the inside of the body
for diagnostic purposes. In medical terminology, it is called magnetic resonance imaging.© R. Masoneuve/Publiophoto/Photo Researchers, Inc.