The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
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The middle of the nineteenth century saw a surge in the spectroscopic investigation and identification of the elements. German chemist Robert Bunsen (1811-1899) and German physicist Robert Kirchhoff (1827-1887) discovered the process of chemical analysis called spectroscopy. Swedish physicist Anders Ångström (1814-1874) measured the wavelengths of the hydrogen spectrum. Swiss mathematician and physicist Johann Balmer (1825-1898) calculated the mathematical relationship between the wavelengths and showed that they form a simple series. And, at the turn of the century, German physicist Max Planck (1858-1947) made sense of it all with his "quantization" of light.
In 1906, the American physicist Theodore Lyman (1874-1954) observed additional lines in the spectrum of hydrogen in the far ultraviolet region with the same mathematical relation calculated previously by Balmer except that these lines required an "n-value" of "1". This led to further investigations and the discovery of other spectroscopic series, all of which have been named after their discoverers. The Brackett series (discovered by American physicist F.S. Brackett) are electronic transitions between the n = 4 state (an excited energy state) and higher energy levels. The energy gap is so small that these absorptions occur in the infrared portion of the spectrum and are only visible using specialized instruments. However, they provide further evidence for the discrete nature of the electronic states in the atom and confirmation of the principles expressed in Bohr's theory of the atom and subsequently, quantum mechanics.