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.
For example, approximately 30% of persons struck by lightning die, and 74% of lightning strike survivors have permanent disabilities. In addition, persons with cranial burns or leg burns from lightning are at higher risk for death than others struck by lightning (6). Sixty-three percent of lightning-associated deaths occur within 1 hour of injury (1), 92% occur during May-September, and 73% occur during the afternoon and early evening. Of persons who died from lightning strikes, 52% were engaged in outdoor recreational activities, and 25% were engaged in work activities (2).