The Dynamic Periodic Chart at ptable.com may be very helpful to those engaged in Chemistry classes of various levels. When you log in you see a standard periodic table:
You may also parse the chart in various ways by checking/unchecking these boxes:
When you click on a particular element a popup takes you to a Wikipedia entry about the element:
You may also use these tabs to change the type of information that is available to you:
For example, if you choose Orbitals and click on Arsenic (As) then you see this information:
Honestly I can tell you little about what that means, but there it is! Maybe I need to go back to Chemistry class myself!