Invisible Lemon Ink
Professor O will help you learn: Lemon juice browns faster than plain paper when warmed, revealing the writing - a gentle heat reaction.
⚠️ An adult must do the warming step. A radiator or warm lamp is safest for children; if an iron is used, only an adult handles it. Keep faces and fingers away from the heat source.
Play through the project step by step, with narration read aloud.
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Steps
Tap any step to play from there — the narration plays inside the player.
📖 Featured in: Kitchen science experiments with cupboard ingredients · Screen-free things to do when they say "I'm bored"
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