Chromatography comes from the Greek ‘chroma’ and ‘graph’, literally ‘color writing’.  It’s a method of separating mixtures out into their component parts.  In this quick and easy experiment, we use chromatography to find out what colors make up black ink in a marker.

You’ll need a few simple items from the dollar store, but I bet most of you have these supplies at home already!

  • coffee filters
  • black marker
  • cup or mug
  • water
  • scissors

Now, here’s the process:

  1. Cut a large circle about the size of your hand from the coffee filter.
  2. Take your black marker and draw a line across your coffee filter circle, about one inch up from the bottom.
  3. In your cup or mug, put just enough water to cover the bottom.
  4. Curl your coffee filter circle so it fits inside the cup or mug.  Make sure the bottom of the filter is touching the water.
  5. Watch the marker line as the water begins to flow up the filter.  As it rises, the different colors used in the ink should begin to separate out.
  6. Leave the filter in the cup until the water has reached the top.  How many colors did your marker contain?
  7. Extension: Try different brands of markers.  Are the colors the same?
  8. Extension: Instead of a line, draw a dot in the middle of your filter circle.  Place the filter on a saucer and drip water onto the dot in the middle.  What happens?
  9. Extension: Try it with different color markers!
chromatography

Image from https://www.flickr.com/photos/nudomarinero/7837891346

This is not only a great STEM activity, but it also brings in Art to make STEAM!  Dry out your filters and use them in a variety of art projects.

%d bloggers like this: