This is a Chem Studies Film, produced by the Chemical Education Material Study for use in its course in chemistry. Molecular Spectroscopy. Collaborators are Dr. Bryce Crawford Junior, Professor of Chemistry and Dr. John Overend, Associate Professor of Chemistry, University of Minnesota. This movie is about molecular spectroscopy. There are in-depth conversations and vivid imagery about how molecules have natural frequencies of vibration and on the understanding of how light waves interact with those molecules. The movie opens with a rainbow to show the spectrum of light. A narrator comes on the screen 1:00. A man uses a prism to create the spectrum of light on a desk 1: 09. A narrator speaks from his desk 1:30. The model of a wave is animated and shows Planck’s constant, 1:50. Waves are used to talk about length or in terms of frequency which are measured in cycles per second 2:30. The disparity in rates for the low and high frequency waves are shown 2:50. The narrator uses an exposure meter to measure the spectrum of light 4:00. How do molecules affect the spectrum? The narrator uses copper sulfate to demonstrate 4:25. The narrator displays a spectrometer 4:48. Parkin Elmer Infraccord Spectrometer, 5:25. A bobber at the end of a fishing line is shown 6:10. A controlled experiment in a pool with waves is used with a metal bobber 6:30. The narrator speaks, 7:15. The narrator stands in front of a blackboard and demonstrates a light wave experiment, 8:07. Electric generator charges to condenser plates for the experiment 8:14. Simulation of the oscillating effect of a light wave experiment 8:30. Scanning the spectrum of different frequencies 9:20. Molecules are interacting with the oscillating electrical field of a light wave in an animation 10:30. The narrator speaks to the camera 11:00. Polyatomic molecule experiment 11:05. The normal mode vibration pattern of the molecule is displayed 12:20. The normal mode is shown in animation 12:40. The faster normal mode is displayed in animation 13:25. Natural frequencies of vibration are shown and how they affect the molecules in animation 14:30. The three frequencies are shown in one screen in animation 14:45. The narrator sits at his desk and shows a carbon tetrachloride molecule, he adds a chloroform molecule and talks about the different infrared spectrums for each molecule. The narrator shows the different spectrums on a graph on the wall of his classroom, 16:20. In an experiment a man contaminates a tetrachloride molecule with a chloroform molecule, 16:36. The narrator discusses an HCL molecule at his desk 18:00. Digital animation shows the measurement of energy and calories per mole in molecules 19:36. The man discusses more complex molecules at his desk and the value of using spectroscopy. Molecular spectroscopy is the key to understanding molecular structure and an understanding molecular structure is the key to understanding modern chemistry. Professor of the study is Glenn T Seaborg. Director of the study is Professor J Arthur Campbell. Producer of the study is David W Ridgway. Consultant is Dr. T.A. Beckman. This film was produced under a grant from the National Science Foundation. Produced by Reid H. Ray Film Industries Inc. St. Paul Minnesota. Molecular spectroscopy is the study of absorption of light by molecules. In the gas phase at low pressures, molecules exhibit absorption in narrow lines which are very characteristic of the molecule as well as the temperature and pressure of its environment. Molecular spectroscopy involves the interaction of electromagnetic radiation with materials in order to produce an absorption pattern (i.e. a spectrum) from which structural or compositional information can be deduced. Electromagnetic radiation is conventionally, and rather arbitrarily, divided into several distinct regions, each of which covers a range of energies that corresponds to a different type of molecular process. Keywords for molecular spectroscopy: Electron Paramagnetic Resonance, Mossbauer Spectroscopy, Molecular Spectroscopy, Spectral Interpretation, Photoelectron Spectro.