Colorful Chromatography Snowflakes
Discover hidden colors while making colorful snowflakes!
What you will need:
- Round, white coffee filters
- Non-permanent markers or felt tip pens in various colors
- Small glass jars or drinking cups (transparent)
- Paper towels and/or newspaper
- Snowflake template (Optional)
Here’s what to do:
- Cover your table or counter (if they can be easily stained) with a couple layers of newspaper or paper towels.
- Fill a small glass jar or transparent drinking cup with about ½ inch of water and set aside.
- Take one coffee filter and lay it out flat on your covered work surface.
- Pick your favorite marker color and draw a circle around the center of the coffee filter. Draw a second wider ring outside of the first.
- Fold your coffee filter in half to make a semi-circle. Crease the fold.
- Fold in half again to make a quarter circle that looks like a piece of pie.
- Place the tip of the filter into one glass of water and hold the rest of the filter so it stays standing upright with only the tip in the water. Watch what happens to your marker circles.
- Once the water reaches the top edge of the filter or when it looks like the marker has spread as far as it will go (wait at least 5 minutes), carefully remove your filter from the water.
- Unfold it and leave it to dry on a couple of paper towels on your covered surface. What does your filter look like now? What happened to your marker circles? Are there any colors you didn’t expect to see?
- When it is dry, fold your coffee filter in half twice to get back to the pie piece shape.
- With the point of the filter facing you, fold your quarter circle into thirds. To do this, take the upper corners of your pie piece and fold them in until they overlap and form three equal-size, overlapping triangles. Crease the folds.
- Carefully cut out small shapes from the long, straight edges and from the rounded edge of your coffee filter to make your snowflake design. Be sure not to cut along the whole edge on either side or the snowflake won’t hold together.
- When you have cut out all the small shapes you want, carefully unfold your coffee filter again to reveal your snowflake design!
- Color Blending: Add more color vibrancy and have fun with color blending! Gather food coloring and paper towels or paper napkins. Again, make sure the work surface is protected. Add a few tiny drops of food coloring to the coffee filters, add some drops of water, more water if you want more blending, and watch the colors spread and blend. Pat the filter with paper towels or paper napkins to slow the spreading as desired.
- Make crafts! When your creations are dry, you can glue them to folded paper to make greeting cards. Or you can have them laminated (by themselves for a see-though look) or onto white or colored paper. You can cut them out into other shapes or strips, to make bookmarks, or use a hole punch and string or yarn to make a hanging ornament for a tree or window! What else can you make?
Take it further:
- Try it again with a black marker. How many colors do you see?
- Try all of the marker colors you have. How many are made up of more than one pigment?
- Compare all of your snowflakes. Can you tell which pigment travels through the water and coffee filter the fastest? Which color is slowest?
- Try using hotter or colder water. Does temperature have an effect on chromatography?
- Color different shapes and designs on your coffee filter. What happens after you put it in the water?
What’s going on?
In this experiment, the coffee filters and water are used to separate the various pigments used in different colors of marker, a process called chromatography. The pigments separate because they dissolve in the water and move through the coffee filter at different rates. The pigments that move the fastest end up near the round edges of the coffee filter while those that move the slowest stay near the center of the coffee filter, which was closest to the water.
You may know that mixing yellow and blue makes green, but did you know that many markers get their color from a combination of two or more pigments? Often, black markers may contain red, blue, and even green pigments. Our eyes detect color based on the light reflected from an object. So an object that we see as red is reflecting red light into our eyes. We see black markers as black because the pigments have overlapped, and no colored light is being reflected back into our eyes.