Atomic Mac 7.0 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The program lies within Education Tools, more precisely Teaching Tools. This Mac app is a product of Black Cat Systems.
From the developer:
The Atomic Mac is a 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. X-ray data (fluorescence and binding energies) is also available. A molecular weight calculator makes it easy to find the molecular weight of compounds.
You may want to check out more software for Mac, such as Atom, Sonic Atom or Atomic Cannon Demo, which might be related to Atomic Mac.