pH is logarithmic scale. An one unit change denotes a factor of 10 difference.
FIGURE 12.17 The pH scale
ranges from 0 to 14, with a value of 7considered neutral. Values greater than
7 are alkaline and below 7 are acidic. The scale is logarithmic, which means
that rain with pH 3 is 10 times more acidic than rain with pH 4 and 100 times
more acidic than rain with pH 5.
