The Challenge: Separate black ink into various colors.
Materials: coffee filter paper, a variety of black markers or pens, long skewers (or straws), a small tub filled with 2 cm of water
Challenge Criteria: Cut the filter paper into long strips that are the same size. You need one strip for each marker/pen you chose to test. Draw a thick black horizontal line 4 cm up from the bottom of each strip with the different markers/pens you chose. Tape the other end of each strip to the skewer. Lay the skewer ends over the top of the tub with water so the ends of the filter papers touch the water, but the black lines should be above the water level. Depending on the size of your tub, you may need to adjust the amount of water. Wait about 5 minutes, watching the water travel up the filter paper.