One thing always leads to another- in life, in science, in all those experiments we call reality. For this experiment, we used the following supplies: a plastic pipette, 3 tubes with colored water (one for each primary color) in them, a test tube rack, a color wheel, a plastic color mixing tray (ice cube tray works well), and a cup of water.
Previously, we colored the water using fizzy color pellets (though a drop or two of food dye works just as well). After the color pellets fizzled out, les petites discovered that they would need a new skill- namely, the ability to pipette- for our next experiment. We set up our color lab on top of one of the girls' desks. Max carefully unscrewed the lids from the test tubes containing our color solutions and then returned them to the rack.
First we had to learn how to use pipettes to move colored water from one place to another. Rather than jump straight into the rainbow, the girls practiced their pipetting skills with the water in the plastic cup. We discussed how scientists use pipettes all the time to carefully meausure different liquids during their experiments. The blow-by-blow:
- Pinch the bulb of the pipette with thumb and fingers and keep squeezing. This pushes the air out.
- While you are pinching the bulb of the pipette, carefully lower the tip of the pipette into the water.
- With the tip of the pipette under water, slowly release your squeeze. Can you feel the water being sucked up into the pipette when you do this?
- Slowly pull the pipette out of the water. Why do you think the liquid stays inside the pipette?
- To remove the liquid from the pipette, squeeze the bulb once more and the water will squirt out.
Each little person practiced using the pipette until they felt comfortable enough to move three teaspoons of water from one cup to another and the back again. Micah and Max could not stop laughing as Milla's pudgy but very able hands learned to use the pipette. Max informed me that "we do this all the time with those straws we get at restaurants, mom". Apparently, I had mistaken what appears to have science in action for mischevious attempts to upset the bourgeois meal conventions of the Tuscaloosa business class.
Max also pointed out that I used this "suction effect" to remove green slime from Milla's nose last year. Fortunately, those humiliating days of unsatisfied bulb suctioning are over since I discovered the amazing (and deeply satisfying) NoseFrida (known in certain circles as the snotsucker).
Now we were ready for the next step- pipetting colored water into the indentation wells and discovering what new colors might emerge. Max went first. He carefully used his pipette to draw up some liquid from the test-tube with the blue-colored water. Then he squirted it into one of the wells of the plastic tray. Before using his pipette to draw up some of the yellow-colored water, Max flushed his pipette in the cup of clear water. He added the yellow water to the blue water in the tray well. The result? Green, of course.
Now it was Micah's turn. She wanted to make "pink", so Max used the color wheel to show her that she should add blue to red. The red water looked pinkish to begin with- so it wasn't surprising when the combination of blue and red came closer to purple than pink.
The color wheel made discussing primary colors much easier. For example, when Max used it to help Micah find out how to make pink, he asked her "What two colors does pink lie between on the color wheel"? Milla could not wait to make her favorite color, orange, and Micah was familiar enough with the wheel to tell her to mix red and yellow. We ended up mixing and creating a whole tray full of colors, including black (which Max made because "it's your favorite color, mom").