The ionic product for water is defined by. KW = [H3O+][OH-] For water at standard temperature and pressure, it is 1.00 x 10-14 mol2/dm6. pKW (which is equivalent to the pH) will be 7 at room temperature, because it is the -log10 of KW, and -log10 of the square root of 1x10-14 is 7.
Lightning has been the second largest storm killer in the U.S. for the last 40 years, exceeded only by floods. A lightning strike can result in a cardiac arrest (heart stopping) at the time of the injury, although some victims may appear to have a delayed death a few days later if they are resuscitated but have suffered irreversible brain damage.
Lightning usually claims only one or two victims at a time and usually does not cause the mass destruction left in the wake of tornadoes or hurricanes. Lightning generally receives less attention than any other weather hazard. During a thunderstorm, each flash of cloud to ground lightning is a potential killer. However, lightning deaths can be prevented if people are aware of the dangers and seek shelter. Lightning can strike as much as 10 miles away from the rain area in a thunderstorm.