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.
Ripeness is indicated by a bright yellowgold color on the skin that at the very least should be present on the eyes around the base of the fruit. Though industry literature states that a fully ripe pineapple may be entirely green, ''mature green,'' it is also true that it may not be ripe. Buying a fully green pineapple is risky. The stem end of the fruit has the highest sugar content and is the ripest portion. The higher up that yellow color goes, the more evenly a pineapple will be flavored. That color, plus a pleasant, mild pineapple aroma at the base are the best guides to ripeness.