Have you ever wondered why a black sketch pen sometimes leaves behind traces of blue, purple, or even green when it gets wet? That’s the magic of chromatography – a fascinating science experiment that lets you separate colors just like a real scientist! Whether you're a student, parent, or teacher looking for an easy and fun STEM activity, chromatography using sketch pens is the perfect way to explore the science of color separation.

🎨 What is Chromatography?

Chromatography is a scientific technique used to separate a mixture into its individual components. Scientists use it to analyze everything from DNA to ink and food dyes. But don't worry – you don’t need a lab coat or fancy equipment to try this experiment. All you need are some simple supplies you likely already have at home!

🧪 Materials You’ll Need:

• White coffee filters or paper towels

• Sketch pens (preferably black or dark-colored)

• A glass or small cup

• Water

• Scissors

• A pencil

• Tape

Optional: Ruler for precise measurement

🧬 Step-by-Step Instructions: Chromatography in Action

1. Cut the Filter Paper:
   Cut the coffee filter into strips, about 1-2 inches wide. These strips will be your chromatography papers.

2. Draw a Line:
   Using a black sketch pen, draw a horizontal line about 1 inch from the bottom of each strip. This is where the color separation will begin.

3. Prepare the Setup:
   Fill the glass with a small amount of water (just enough to touch the bottom of the paper strip). Tape the top of the strip to a pencil and lay the pencil across the glass so the strip hangs into the water.

4. Watch the Magic Happen:
   As the water moves up the paper through capillary action, it will carry the ink with it. Soon, you’ll see different colors start to separate and travel upward!

5. Observe and Record:
   After a few minutes, remove the paper and let it dry. Observe how many colors appeared from a single ink spot. You might be surprised at the hidden rainbow inside your sketch pens!

🔬 The Science Behind Chromatography

Here’s how it works: sketch pen ink is made up of different colored pigments. Some of these pigments are heavier or stickier than others. As the water moves up the paper, it pulls the pigments with it. The lighter, more soluble pigments travel farther, while the heavier ones stay behind. This is the principle of paper chromatography – separating a mixture based on the movement of its components through a medium.

👩‍🔬 Learning Outcomes and Fun Facts

• STEM Learning at its Best:
  This experiment is a fantastic introduction to chemistry and scientific observation for students in elementary or middle school.

• Color Composition Awareness:
  Many kids think black is just black – until chromatography reveals the secret colors within!

• Hands-On Science at Home or School:
  Ideal for science fairs, classroom experiments, or homeschooling activities.

• Boosts Curiosity and Critical Thinking:
  Ask questions like: What happens with different colors? What if we change the type of paper or liquid?

🛡️ Safety Tips

• Use non-toxic sketch pens.

• Supervise younger children, especially when handling scissors or small cups of water

• Play Safely.
  
  
  

✨ Final Thoughts

The Chromatography with Sketch Pens experiment is a simple, engaging, and educational way to bring science into everyday life. It not only introduces kids to core scientific principles but also sparks creativity and curiosity. By separating the hidden colors in ink, students learn that science is all around them — even in something as simple as a sketch pen.

So, grab your supplies and start exploring! Who knew that science could be so colorful?