Resumen de A Unifying Approach to Absorption Spectroscopy at the Undergraduate Level
This article suggests that when introducing the topics associated with absorption spectroscopy, the students can greatly benefit from a preliminary discussion of the principle of frequency matching. Virtually all types of absorption spectroscopy share a simple but critical requirement: the frequency of absorbed radiation must exactly match the frequency of some inherent or induced periodic motion of the particles. If the particles are not engaged in such motion, there can be no absorption. This principle is a straightforward consequence of the necessity for the electric or magnetic oscillations of the incident radiation to match in both frequency and orientation (polarization) the characteristic electric or magnetic oscillations of the particles absorbing the radiation in order for constructive interference, resonance, and energy exchange to occur. Three of the most common types of spectroscopy (vibrational, electronic, and nuclear magnetic resonance) are discussed as examples of this principle.
