Atomic PC is a program that presents you the periodic table of the elements.
This application works with Windows, but it also has a version for Mac users.
It has a very simple interface, making the application easy to be used by everyone. The first thing that I noticed in this program is that it is organized very well. The home page opens directly with the periodic table of the elements. If you click an element, you get details about the main characteristics of it, as well as about its isotopes, ions, shells, X-ray, Misc, and spectrum. There is a short description of the crystal structure of each element, its density, the melting or boiling point, and much more important aspects. If you find it difficult to understand the periodic table, there is an option that changes the order of viewing the elements, called 'Periodic Spiral'. As its name already says, all the items are displayed in a spiral form. However, if you use this option you get fewer details about the elements, such as the atomic number or the type of the respective one. The most important function is that it allows you to change the way the elements can be sorted out. For example, you can see the whole periodic table depending on density, heat of vaporization, heat of fusion, thermal conductivity, and many other physical properties. The program also gives you an ability to see a list of all the elements, their abbreviation and their atomic number.
In conclusion, I think this is a very practical application. Because of its simple but efficient interface, you may find out almost whatever you want from the periodic table of the elements. However, I think this application could use a comparing option between two elements.