For the month of April, This is Science is turning flowers different colors - just like when your tongue turns purple when you drink grape juice. It's simple chemistry, in which molecules that are alike follow one another up the stem of the flower, like liquid in a straw. Try it at home and see what colors you can make.See more science experiment videos
White flowers (though you can experiment to see what happens with different colors)
Scissors to clip the steps
Small vases or cups
Make sure to buy flowers that are open, not budding.
Put about 30 drops of food coloring in about a cup of water.
Put one flower in each cup
Split the stem in half and put half in one cup and half in another
Leave them for 4 to 24 hours. Keep checking to see if the stem is progressively turning color.
The flowers change colors because of two scientific concepts: cohesion and transpiration.
The plant stem acts like a straw, pulling the water up to the flower petals.
Cohesion is simple. Water (any matter, really) is made up of molecules. Molecules are attracted to other molecules that are similar to them. So if you have a bunch of, say, green molecules, they will follow each other up the straw, or plant stem.
Transpiration is kind of like sweating. The water goes up the plant stem, then evaporates into the air, to be replaced by other liquid traveling up the plant stem (which is why we need to keep watering plants). The transpiration acts like a sucking action on the straw - it pulls the water up.