Atomic Spectra-Graph Todd Sumvell
Proiect SERAPHIM. Universitv of Wisconsin-Madison "Atomic Spectra-Graph" displays the emission spectra of over 80 elements. The emission spectra are displayed over the range 280-850 nm. The data are encapsulated into Microsoft Excel spreadsheets. A macro program allows the user to select an element, loads the appropriate data sheet, calculates the spectra, and displays a black and white line spectrum and a color visible spectrum.
The emission spectrum of carbon as displayed in "Atomic SpectraGraph". The majority of the spectral data is taken from the Handbook of Chemistry and Physics, 59th ed. Emission data for a few of the elements was taken from the NBS Monograph 145, Part I, entitled Tables of Spectral-LineIntensities, Arranged by Elements. For most of the elements, not all of the spectral lines are included, only those ofhighest intensity. In order to kve the visible spectra enough lines, the 2(i most intense fines ofthe visible spectrum a k included (inclusiveof anv other lines in the vis~hlcrange of equal intensity to the twentieth line) as well as any inthe applicable nonvisible regions with equal or greater intensity. When the black and white spectra are drawn, three levels of spectral line intensity are used. The highest intensity line of a particular element is determined, and all the other lines of that element are compared to it. A line that is less than 30% as intense the most intense line, is considered a low intensity line, and is drawn in light gray. Aline that is 30-70% as intense as the highest intensity line is considered to be of medium intensity, and is drawn in dark gray. A line greater than 70% the intensity of the highest intensity line is consider high intensity and is drawn in black. In drawing the color spectra, only two levels of intensity are taken into account (Excel has no capability of lightening and darkening colors): if a line is greater than 70% as intense as the most intense line of that element, it is considered high intensity, and has a width of two pixels; all other lines are considered low intensity and have a width of one pixel.
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Journal of Chemical Education
