What a neat game, I loved it! The charged areas are a really clever concept. I think there is a lot of potential to develop this into a full game.
It took me a little while to figure out what to do. I guess it's been too long since chemistry class :-). The intro screen is a bit minimal. If you take this game further, a scripted tutorial could be a way to help new players.
Graphics are simple but fine for this game. Music is a bit repetitive, but this is very forgivable seeing you did all this well within the 3 hour limit.