Here's where things get fun. Just like the number of reps, 3-6 sets is the best range of volume for this training method. If you like your workouts paced like clockwork, take 30-60 seconds rest between each exercise.
The natural attraction between positive and negative keeps the ions surrounded by water molecules and therefore dissolved in solution. Many biochemicals are either polar molecules or charged ions (or both) so water makes an excellent solvent for them.
Hydrogen bonding and the polarity of water also explain its solvent properties. Water has a remarkably high boiling point for a substance with such small molecules. In order for a substance to boil, the molecules of the liquid must have enough energy to overcome the forces of attraction between them.