pH Scale: The scale used to specify how acidic or basic water-based solutions are at room temperature. Like measuring your mood from happy to sad!
Litmus Paper: A type of paper infused with certain chemicals which changes color when exposed to acids or bases, much like your mood ring reacting differently under different emotional states.
Phenolphthalein Indicator: A commonly used acid-base indicator that is colorless in acidic solutions and pink in basic solutions. It's like a mood ring that only shows two emotions - happy (pink) and neutral (colorless).