As semiheavy water, HDO, occurs naturally on Earth in regular water at a proportion of 1 part per 3200, it may be separated from regular water by distillation or electrolysis and also by various chemical exchange processes, all of which exploit a kinetic isotope effect. In short, the difference in mass between the two hydrogen isotopes translates into a difference in the zero-point energy and thus into a slight difference in the speed at which the reaction proceeds. Once HDO becomes a significant fraction of the water, heavy water will become more prevalent as well as water molecules trade hydrogen atoms very frequently. To produce pure heavy water by distillation or electrolysis requires a large cascade of stills or electrolysis chambers, and consumes large amounts of power, so the chemic