March 25, 2014 — After being thwarted by a snow day in February, fourth-grade Science Experiment Day came to Jackson Heights on March 3—involving hundreds of Alka-Seltzer tablets, food coloring, balloons, and more!
Fourth-grade teacher Jodene Eyer has been leading the much-anticipated Science Experiment Day for several years, as part of a hands-on approach to a unit on solutions, suspensions, and chemical reactions. The event involves multiple experiment stations where students get to create chemical reactions with common liquids such as milk, liquid dish detergent, and food coloring.
At one station, students got to make their own “lava lamps” using plastic water bottles, colored suspensions, and an Alka-Seltzer tablet. At another popular station called Rockets, students drop an Alka-Seltzer into a plastic film canister of water and watch the phase change from solid to liquid to gas –blasting the canister up to the ceiling with a big “pop.”
“This year we increased the number of experiments,” says Mrs. Eyer. “We had 8 stations with a total of 10 experiments for the kids to try.” New this year was a station called “Balloon Bottles.” Using a plastic water bottle and Alka-Seltzer tablets, students were able to trap the gas created by the chemical reaction inside a balloon.
“Erosion with sugar cubes was another new experiment where the kids made a sugar wall and used food coloring and water to break down the sugar cubes and watch the sugar wall erode away,” says Mrs. Eyer. “When dissolving M&M's and Skittles in water, the kids learned that the M and S that appear on the candy do not dissolve and will float to the top of the water, while the candy dissolves in the water.”
Big Cross students from Jeanne Howe and Julie Curtis’ classes came over to Jackson Heights to participate in the experimentations with their peers. Students’ favorite experiments included the film canister rockets, lava lamps, and milk fireworks—an experiment that uses food coloring, milk, and dish soap to demonstrate polarity of molecules. And beyond science instruction, at least one student came away with life lessons as well.
"I learned that if you want your experiment to work you need to read the directions," noted a fourth-grader.
See the photo slideshow of Science Experiment Day below.
A quick explanation of the milk fireworks experiment
Milk is mostly water but it also contains vitamins, minerals, proteins, and tiny droplets of fat suspended in solution. Fats and proteins are sensitive to changes in the surrounding solution (the milk). The secret of the bursting colors is the chemistry of that tiny drop of soap. Dish soap, because of its bipolar characteristics (nonpolar on one end and polar on the other), weakens the chemical bonds that hold the proteins and fats in solution. The soap's polar, or hydrophilic (water-loving), end dissolves in water, and its hydrophobic (water-fearing) end attaches to a fat globule in the milk. This is when the fun begins. The molecules of fat bend, roll, twist, and contort in all directions as the soap molecules race around to join up with the fat molecules. During all of this fat molecule gymnastics, the food coloring molecules are bumped and shoved everywhere, providing an easy way to observe all the invisible activity.