Isotopes
Reference: Isotopes (includes videos)
Ions
Reference: Ions (includes videos)
Program is found here.... (click for link)
Click on the video image in the middle of the screen.
Click on the "Game Tab" - choose the first game
Every time you do the game, the atoms change so practice as much as you'd like!
Once you finish the first game, go to the second. Keep playing till you can complete 4 games at 100%