National Standards for Grade Levels 4-8
 
Dramatic color changes and kitchen chemistry make investigating indicators an appealing way for younger scientists to explore acids and bases. Using an inquiry approach, students predict, observe, and analyze with familiar household items. First, they test common items to see if they are acids by observing how they react with baking soda. Second, they test substances using natural indicator solutions from red cabbage and black bean juice. Third, they are introduced to the terms acid and base and learn to use blue and red litmus papers. Forth, they compare the natural indicator system to using pH paper and color charts, Fifth, they make and test their own Universal Indicator Test Strips using Universal Indicator Solution and filter paper. Sixth, they create a solid gelatin indicator system to use for testing unique samples. Includes directions for the isolation red cabbage and black bean juice to be used as natural indicators. Allow several hours for hands-on investigation. Designed for 24 students working in groups of four.