More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion.[1] Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, at pH 7, being neither an acid nor a base.
Report Abuse. 1  Ripe Plum. 2  This Site Might Help You. 3  A plum is ripe when its soft and a really dark purpleish color.  they should be a little soft and should have a smell (plum smell) strawberry Â· 9 years 1  ago. Smell it, squish it and last but not least bite 2  it! plump(really soft) and dark all 3  over. the color tells u everything u need to  know.
Plums are generally in season somewhere in the United States from the end of May all the way into October. The varieties that have their origins in Japan ripen first, and the European varieties, which we usually refer to as prune plums, ripen later.