The Invisible Ink Experiment

I've always been fascinated with invisible ink ever since I was a little kid. Finding them on sale during my elementary school's book fair was always fun, and I made sure to get them every year. As time went by, I started to develop an interest in finding out how the world and how science works. So, today I am going to explain how you can create your own invisible ink with only a few household items, and I will explain the science behind the experiment! Materials List

• Lemon (or lemon juice)

• A small bowl or container

• A paintbrush, cotton swab, or toothpick for writing

• White paper

• Light bulb or an iron set to a low temperature

• A heat-resistant surface or ironing board (if using an iron)

Experiment Rundown You are going to write a message or draw a picture using lemon juice as ink on a lank white piece of paper. Let it dry completely. To reveal the hidden message, gently heat the paper with a light bulb or an iron set to a low temperature. The lemon juice will turn brown, making the message visible.

Experiment Procedure

1. Prepare the Lemon Juice:

• Cut a lemon in half and squeeze the juice into a small bowl or container. If you don't have a lemon, you can use bottled lemon juice, but fresh lemon juice is preferred.

2. Write Your Message or Draw a Design:

• Dip a paintbrush, cotton swab, or toothpick into the lemon juice.

• Use the lemon juice to write your message or draw a design on a sheet of white paper. Ensure that you apply enough lemon juice to make your writing or drawing visible but not so much that the paper becomes soaked or torn.

3. Allow the Paper to Dry:

• Let the paper sit undisturbed until the lemon juice is completely dry. This may take some time, so be patient.

4. Prepare for Heat:

• Once the lemon juice is dry, you're ready to reveal your hidden message. You can use either a light bulb or an iron for this step.

If using a light bulb:

• Place the paper on a heat-resistant surface, like a table or countertop.

• Hold the paper a few inches above the lit light bulb. Move it back and forth, keeping it at a safe distance to avoid burning the paper. You should start to see your message appear as the lemon juice darkens.

If using an iron:

• Set your iron to a low temperature setting (no steam) and allow it to heat up.

• Place the paper with the hidden message on an ironing board or another heat-resistant surface.

• Gently press the warm iron over the paper. Move the iron around the area where you wrote with lemon juice. Be careful not to scorch the paper; a low temperature is sufficient to reveal the message.

5. Observe the Message:

• As you apply heat with the light bulb or iron, the lemon juice-treated areas of the paper will start to turn brown. Your hidden message or drawing will become visible as the lemon juice reacts with oxygen and darkens.

6. Enjoy Your Invisible Ink Message

• Once the message is fully visible, remove the paper from the heat source. Your invisible ink message has now been revealed!