You don't need any equipment to play this game.
The players are moving around the playing area, they represent free atoms. The referee now shouts a random (but small) number; exactly this number of atoms have to group together to molecules. The remaining players (too few to form a molecule of valid size) are out of the game, or get a task. Additionally, the molecules might get a task, might introduce each other, etc.
Then, another round start.
After a few rounds, the current molecules might be instructed to stay together and form a group for the upcoming activities.