Final answer:
Phenolphthalein and bromothymol blue are two types of chemical indicators that show the presence of a base with a pH greater than 7.
Step-by-step explanation:
There are several types of chemical indicators that show the presence of a base with a pH greater than 7. Two common examples are phenolphthalein and bromothymol blue. Phenolphthalein is colorless in acidic solutions (pH < 8.3) and turns pink or red in basic solutions (pH > 8.3). Bromothymol blue is yellow in acidic solutions and changes to blue in basic solutions.