Materials Needed

-Lemon juice
-Cotton swab or paintbrush
-White paper
-A lamp or light bulb (for heat)

Instructions

1. Dip the cotton swab or paintbrush into lemon juice.
2. Use it to write or draw on the white paper.
3. Let it dry completely (it will be invisible).
4. Hold the paper close to a heat source (like a lamp or light bulb), and watch the writing slowly appear!
   
   

Explanation: The lemon juice oxidizes when heated, revealing the invisible writing.