We have experimented with chromotography before. You can play around with them, too, if you would like.
|We used a straw cut in half to tape and hang our samples on. We used brown ink, brown food coloring and a brown washable marker to make our samples. We used a pipette to put our ink on the paper towel strips.|
If you would like to set up the samples for your child, then gather together four pencils, straws (you can probably use two straws cut in half) or dowels, some tape, four clear plastic cups, a piece of paper towel or coffee filter, a brown marker. You will also need two of the following for ink -either brown inks, brown ink pens, or red and green food coloring, which will act as an ink substitute. You will need these two inks and one marker. If you are using the food coloring as your ink substitute, you will need to mix them 2 parts red to 1 part green. Start with 10 drops red and 5 drops green and see if that is enough. Add more in the same ratio as you need it. Put the inks in sealed containers (like pill bottles). Label one "Brown Ink from Mr. Green" and the other "Brown Ink from Prof. Plum". If you are using an ink pen, you will need to take the pen apart to get to enough ink to use, but don't do this until you are about to start or the ink will dry up. You can do this for the student if they are young. For each student who will be doing the experiment, cut a paper towel into one inch by three inch strips and make a stain across the middle of one strip using a brown marker. This is a piece of your ransom note. I actually wrote a word to make it look more like a piece of ransom note, but you don't need to. You can make just a good size dot if you want. (You might want to make an extra just in case you need it, especially if several children are doing this seperately.) Allow the ink on the strip to dry. Keep the same marker for your child to test. Have whatever you are using for the ink pens of Mr. Green and Prof. Plum ready.
Now you have set up for your student, one piece of stained paper towel that is the piece of ransom note, some blank paper towel strips, your brown inks, a brown marker and your straws and cups.
|Have your student make a dot in the middle of a blank piece of paper towel with the marker. This is the marker found in the kitchen. Label this "Marker from Kitchen" or just "Kitchen."|
|Have your students watch what happens when the water moves through the dots. See if they can see if the marker or one of the inks matches the mystery dot. |