Final answer:
A characteristic of a base is that it turns blue litmus paper red and has a bitter taste. It reacts with acids to produce salt and water and does not react with metals like acids do.
Step-by-step explanation:
The characteristic of a base is that it turns blue litmus paper red. Bases, which are the chemical opposites of acids, have several distinct properties, including changing the color of indicators such as litmus and phenolphthalein. When a base comes into contact with litmus paper, it turns blue, whereas phenolphthalein changes to pink in a basic solution. Additionally, bases are known for their bitter taste, slippery feel, and they react with acids to produce salt and water. Common examples of bases found in everyday life include soap, toothpaste, bleach, cleaning agents, limewater, ammonia water, and sodium hydroxide.