Red cabbage juice works as a natural universal indicator, displaying a range of colors across the entire pH scale due to a pigment called anthocyanin. Materials: Chopped red cabbage leaves Water Blender or pot Strainer/coffee filter Small, clear containers (e.g., cups or an ice cube tray) Various household liquids to test (e.g., vinegar, lemon juice, milk, baking soda solution, soap solution) Instructions: Make the indicator solution: Blend or boil chopped red cabbage leaves in water until the l