Half Term Experiments
Autumn 1
The children in Year 2 helped select the Science experiment for this half term.
Ghostly Invisible Ink
You are going to write using invisible ink.
Prediction Questions
Think about these questions. You can write down a few ideas or just chat to someone else about what you think.
• How do you think you’ll make invisible ink?
• How might you reveal the hidden writing?
Carrying Out the Experiment You will need:
• freshly-squeezed lemon juice
• small bowl
• cotton buds
• white paper (cartridge paper works best)
• hairdryer
Instructions
1. Squeeze some lemon juice into a small bowl.
2. Dip a cotton bud into the lemon juice and use this as your writing tool to write a secret message onto the white paper.
3. You’ll see the juice fade as your message seeps into the paper.
4. Ask an adult to help you use a hairdryer on a low setting on your paper.
5. Watch what happens!
Explaining the Science
When lemon juice is heated up, it decomposes and releases carbon. Once the carbon touches the air, it oxidises which allows you to see the message. Oxidation is what causes cut-up fruits to turn brown (like an apple slice). It’s also the process that causes some items to rust.