Indicators are helpful tools that show us if something is an acid or a base. They help us learn more about their properties and how they act.

For example, acids change blue litmus paper to red. On the other hand, bases change red litmus paper to blue. This is a simple test that helps us find out if a substance is acidic or basic.

Common Indicators and Their Colors:

1. Litmus:

   • Acidic (pH < 7): Red
   • Basic (pH > 7): Blue

2. Phenolphthalein:

   • Acidic (pH < 7): Colorless
   • Basic (pH > 8.2): Pink

3. Universal Indicator:

   • Shows colors from red (strong acid, pH 0) to violet (strong base, pH 14)

Understanding the pH Scale

The pH scale goes from 0 to 14. It tells us how acidic or basic something is.

• A pH of 7 is neutral, like pure water.
• Acids usually have a pH lower than 7, while bases have a pH higher than 7.

Using these indicators helps us see the nature of different substances. This makes learning about the chemical world around us more exciting!