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INTERACTION OF MATTER WITH SPECIFIC REGIONS OF ELECTROMAGNETIC RADIATION

المؤلف:  Max M. Houck، Jay A. Siegel

المصدر:  Fundamentals of Forensic Science

الجزء والصفحة:  p98-99

2026-06-28

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INTERACTION OF MATTER WITH SPECIFIC REGIONS OF ELECTROMAGNETIC RADIATION

For many years, analytical chemists have exploited the ways that radiation interacts with matter. As it turns out, the particular effects that matter has upon light (and vice versa) depend upon the energy content of the radiation and the type of matter. Forensic and analytical chemists are interested in the wavelengths and/or frequencies of radiation absorbed by matter. When a substance is exposed to electromagnetic radiation, it undergoes changes that may or may not be reversible and which depend upon the energy of the radiation. For example, gamma radiation can cause matter to lose electrons and undergo irreversible changes. In the case of living matter, radiation of this high energy can cause mutations in tissue that may result in cancer or some other disease. Forensic science, however, is more concerned with what happens to a substance when it is exposed to light of much lower frequencies and energies. There are two principal regions of light that are most important in characterizing evidence: the ultraviolet/visible (UV/visible) and the IR. Remember, a forensic scientist is most interested in com paring evidence from a crime scene (unknown evidence) to some object or material (known evidence) to see to what extent they may be associated with each other. This is accomplished principally by comparing as many physical and chemical properties as possible. The more characteristics the known and unknown samples have in common, the higher the degree of association. Behavior of matter when exposed to light is a very important chemical property and is greatly exploited by forensic scientists.