Summary Write a note in (nearly) invisible ink Science content Chemistry: States of Matter, Properties of Materials (K-7) Chemistry: Chemical Changes (2, 7) Lessons activity is in Forensic science Materials saturated baking soda solution in a tub Q-tips card to write note on grape juice in a tub paintbrush Procedure Write your note in baking soda solution. Allow to dry. The note will be barely visible (though not invisible). Paint grape juice over the note to make it visible. (The grape juice turns a different colour when covering the basic baking soda solution). Notes Other ideas for invisible ink: lemon juice invisible until heated Ex-Lax tablets in water (contain phenopthalein) to write. Add baking soda solution to visualize. Grades taught Gr K Gr 3 Gr 4
