Answer:
1. Base, in chemistry, any substance that in water solution is slippery to the touch, tastes bitter, changes the colour of indicators (e.g., turns red litmus paper blue), reacts with acids to form salts, and promotes certain chemical reactions (base catalysis).
2. If there are more positively charged hydroniums than negatively charged hydroxyls, then the substance is acidic. If there are more negatively charged hydroxyls than positively charged hydroniums, then the substance becomes basic. pH actually stands for the "potential (or power) of hydrogen."