I wrote this little program while I waited for some SDKs to download. It's just a toy to play with the dynamics of charged particles. While not directly accurate to any real world physical model (not least because it is only 2D), it can demonstrate some principles of chemistry. The principles of molecules and chemical reactions can be seen as charged particles attract, assemble and react to the presence of new charges.
Left, Middle, and Right mouse buttons place particles of -1, random, +1 respectively
Use number keys 1-9 & 0 to place particles in a range of -1 to +1