Seniors, 3's Share the Joy of Scientific Discovery

Five BT seniors spent part of their last day of classes in PreSchool lobby, introducing our PreSchool 3’s classes to exciting scientific concepts such as pH balance, water surface tension, static electricity and more. High School science teacher Dr. Adam Cornish explains each activity:

Batya R. ‘17 demonstrated that the carbon dioxide in our breath can change the pH of water. She added an indicator to water, turning it green at a neutral pH. She then blew into the water, adding carbon dioxide and slightly acidifying the water, making it turn yellow. The students could then add various agents to the water to further change the pH and also changing the color.

Allison R. ‘17 showed how corn starch reacts strangely when dissolved in water. Mixing the components together, along with some food coloring, the students could see and feel that the mixture would be hard initially and then melt a moment later. This is because the starch/water mixture is an example of a non-Newtonian liquid that doesn't seem to obey the normal rules of how liquids behave.

Adi S. ‘17 demonstrated how some things can float on the surface of water and what happens when detergent is added to the solution. She did this by adding pepper to water and observing the floating particles. Then, students added a drop of detergent to the surface with their finger, which disrupted the surface tension and caused floating pepper to "run away" to the edges of the plate.

Nina G. ‘17 gave a demonstration of static electricity by using two balloons and an aluminum can. Rubbing the balloons on cloth imparted a slight charge to the balloons and they then resisted being brought close to one another. The static electricity also attracted hair to the balloons, as well as attracting the metal of the can, causing it to roll across the table towards the balloon.

Marcelle P. ‘17 enjoyed showing how some liquids don't mix well with each other, creating a mini lava lamp for the students. She added water and vegetable oil (along with food coloring) to a small water bottle. After discussing how the two layers separate because they don't mix, she then added an Alka-Seltzer tablet, which created bubbles and caused the two layers to mix in colorful blobs.