About This Lesson
This lesson should be taught near the beginning of an ocean acidification unit to give students a strong understanding of
pH, acids, bases, and the pH scale. Students will explore a large, physical model of the pH scale and use familiar household substances to investigate where different materials fall on the scale. Students will then locate ocean water on the pH scale and explore how a seemingly small decrease in pH can represent an important change in ocean chemistry. This lesson works especially well after students have been introduced to acids and bases or immediately before a hands-on pH indicator investigation such as Making a Rainbow of pH.
