Pure water has a pH of 7 because (a) its surface tension equally attracts acids and bases. (b) its polarity results in a molecule with a positive and a negative end. (c) its ability to dissolve carbon dioxide adjusts its natural pH. (d) its capillary action attracts it to the surfaces of solid substances. (e) its \mathbf{H}^{+}H
+
concentration is equal to its \mathrm{OH}^{-}OH
−
concentration.
