The Atomic Mac is the award winning periodic table of the elements for the Macintosh. In addition to the usual information found in such programs, The Atomic Mac also contains a wealth of nuclear information on each isotope, including half life, decay mode, and daughter products. No other periodic table of the elements has more data than The Atomic Mac!
X-ray data (fluorescence and binding energies) is also available, as well as electron shell information and alpha particle energies. In addition you can view the visible spectra, and get a table of wavelengths and relative amplitudes.
A molecular weight calculator makes it easy to find the molecular weight of compounds. A shaded diagram showing the ranges of physical properties makes it easy to visualize relationships across the periodic table.
The Atomic Mac is available for US$15. You can find more information at the Black Cat Systems web site.