Which of the following statements about the pH scale is not true?
A. In a pH expression, the hydronium ions, H3O+, can be abbreviated simply as H+.
B. A solution with a pH of 4 has twice the [H+] of a solution with a pH of 2.
C. The pH scale is based on a scale involving powers of 10.
D. pH is a scale that indicates the acidity of a solution.