You can make a secret message with baking soda by mixing it with water to create an invisible ink, writing your message, letting it dry, and then carefully heating the paper to reveal it.
Materials Needed
To get started with your invisible ink project using baking soda, you'll need just a few simple items, most of which you likely already have at home.
| Item | Description |
|---|---|
| Baking Soda | The key ingredient for your ink. |
| Water | Used to dissolve the baking soda. |
| White Paper | The surface for your secret message. |
| Writing Tool | Cotton swab, toothpick, or small paintbrush |
| Heat Source | Iron (with adult help) |
Steps to Create Your Secret Message
Creating a secret message with baking soda is a fun and engaging process. Follow these simple steps:
Step 1: Prepare the Invisible Ink
The first step is to create your "ink" solution.
- Mix equal parts water and baking soda. Stir the mixture until the baking soda is dissolved as much as possible. This solution will be your invisible ink.
Step 2: Write Your Message
Now it's time to put your message onto the paper.
- Use a cotton swab, toothpick, or paintbrush to write a message onto white paper, using the baking soda solution as “ink.” Dip your chosen tool into the solution and carefully write or draw your message on the paper. The message will appear wet, but should be mostly invisible once dry.
Step 3: Allow the Ink to Dry
Patience is key for the message to disappear.
- Allow the ink to dry. Set the paper aside and let the baking soda solution dry completely. As it dries, the message should become virtually invisible.
Revealing Your Secret Message
Once your message is dry and hidden, you'll need to apply heat to make it reappear. This step requires caution and adult supervision due to the use of heat.
Step 4: Apply Heat
Heating the paper causes the baking soda residue to brown before the paper does, revealing your message.
- With adult help, heat the paper by ironing it. Place the dried paper on a safe, heat-resistant surface (like an ironing board). Have an adult carefully run a warm iron over the paper. As the heat is applied, the areas treated with the baking soda solution will turn brown, making your secret message visible again!
Other methods for applying heat could include carefully holding the paper near a light bulb or warming it in a low oven (with extreme adult supervision and caution), but ironing is a common and effective method.
This simple science trick demonstrates a chemical reaction where heat causes the baking soda residue to oxidize and darken.
