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.
Commercially grown plums are picked before they are ripe and allowed to ripen after picking. When ready for sale, they are either gassed with ethylene gas or allowed to ripen at room temperature. If you purchase plums that are unripe, it is worth the small effort to allow plums to ripen before eating.