This is primarily designed for science students of high school and college age. Practice and learn 50 terms and facts associated with atomic structure and it's history. It also covers 10 electron configurations, 10 electron dot diagrams, and 10 energy level populations. The answers move about and must be shot with a cannon. The difficulty increases with higher levels. There are eight levels in all. A score report is displayed at the end showing each level played. Music may be turned off. This program is totally free and may not be sold or distributed for profit. It needs no permissions for installation. Also, it does not access the internet or require any personal information. This app has been run successfully on a Samsung Galaxy S8+, Samsung TabS2, Kindle Fire HD and a Samsung Note8. It will work on Android 4.0 through 8.1 and higher. The app is offered for FREE to the Android community and is not to be sold or distributed for profit. Send all comments and questions to rtcarman47@gmail.com