Spy movies are the absolute coolest with their super secret gadgets and gear. We’ve got the recipe on how to write your own invisible ink messages, just like the spies do!
What you need:
- 1 Lemon, halved
- Small bowl
- White computer paper
What you do:
First, squeeze the lemon halves into the small bowl. Next, add two or three drops of water into the lemon juice and mix with the spoon. Dip the Q-tip into the mixture in the bowl and write a message on the white computer paper. Now, you have an invisible message!
Curious as to how to read it? Hold the paper with the message up to the lamp. After a bit of time, the message will reveal itself!
Questions to consider:
- Why did you need to hold the paper up to the lamp in order to see the message?
- What other ways could you write a secret message?
- Why did we use lemon juice?
Why it works:
When the kids held their top secret messages up to the lamp, the heat from the bulb oxidized the lemon juice, turning it from clear to brown. Oxidation is the process of a substance becoming combined with oxygen. This revealed the message against the white background of the paper.