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Spectra of Atoms and Molecules Peter F. Bernath
Publisher: Oxford University Press

Single atoms or molecules emit light in a form called line spectra. High-resolution atomic force microscopy (AFM) has been extended to a new application—taking before and after pictures of individual molecules as they undergo a chemical reaction. A group led by Structural identification techniques such as mass spectrometry and nuclear magnetic resonance spectroscopy sometimes fail, such as when all of the products have the same mass and NMR spectra of product mixtures have overlapping peaks that are hard to resolve. The images were acquired with the Cassini spacecraft wide-angle camera These reactions eventually lead to the production of carbon- based aerosols, large aggregates of atoms and molecules that are found in the lower layers of the haze that enshrouds Titan, well below 300 miles (500 kilometers). Images taken using red, green and blue spectral filters were combined to create this natural color view. Molecules are made up of many different atoms, and those atoms crowd close to each other in ways that make one atom interfere with the normal spectrum of another. Absorption can be plotted in a wavelength, frequency or wave number. An atom or molecule that is reasonably isolated (such as in a gas at ordinary temperatures and pressures) will radiate a discrete set of frequencies called a line spectrum. A spectrum is a type of “fingerprint” that characterizes a molecule or atom. Near IR absorption spectrum of dichloromethane IR absorption spectrum (Photo credit: Wikipedia). The molecules need to contain polar bonds, even if they are not polar overall. Absorption spectrum is the plotting of the energy that is absorbed by an element or substance.