Final answer:
Acids have a sour taste, can change the color of indicators, react with metals to produce hydrogen gas, and can conduct electricity.
Step-by-step explanation:
An acid has a sour taste, such as lemons, vinegar, and sour candies. It can also change the color of certain acid-base indicators, like turning blue litmus paper to red.
Acids react with active metals to produce hydrogen gas, as shown in a single-replacement reaction.
Additionally, acids have the ability to conduct electricity.