In this experiment, we'll learn how to change the color of a white chrysanthemum using food coloring. This experiment can be performed with accessible materials at home.
Equipment
White chrysanthemum (or, alternatively, white roses, or other white flowers)
Several different food colorings (available at your local supermarket, typically in the baking goods aisle)
Cups, jars or test tubes – same number as food colorings.
Instructions
Cut the flower stems so that 5 cm are left attached to the flower.
Place each flower in a vessel with some water already dyed with your chosen food colorings, and let soak overnight.
Surprise – The flowers are no longer white!
After a few hours
Right after putting the flowers in food coloring
After a few hours
Try this: a stem can also be cut down the middle and dipped in two different vessels with different colorings to achieve a marvellous effect.
Explanation
Water has a trait allowing it to go up very narrow tubes, a phenomenon called "capillary action". Inside the stem, there are thin tubes where the colored water can travel through, and transport the coloring to the petals.
Under "Ask Our Experts" you can find extensive explanations on capillary action.
Another experiment that has to do with capillary action and can be performed at home is called "Water Escaping a Glass".
Extra Information
Check out this presentation about the experiment and other topics from the Davidson Institute's "Science by Mail" program. This program teaches various scientific topics, and this particular presentation is taken from a computerized workbook about fluids. (Click "Play" to start the presentation.)
Extra Information
Check out this presentation about the experiment and other topics from the Davidson Institute's "Science by Mail" program. This program teaches various scientific topics, and this particular presentation is taken from a computerized workbook about fluids. (Click "Play" to start the presentation.)
Dr. Avi Saig
Department of Neurobiology and Davidson Institute of Science Education
Weizmann Institute of Science
Article translated from Hebrew by Aviv J. Sharon, M.Sc. student at the Weizmann Institute of Science.
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