Volunteering at the Boys and Girls Clubs of San Antonio Fall STEM Fest
SACNAS prepared a set of hands-on experiments for kids that allowed them to explore simple concepts in biology, chemistry, and physics. They started with a demonstration of iodine staining, which utilizes iodine to test for the presence of starch. To test this, they asked the kids to add a few drops of iodine solutions to corn starch, potato chips, paper towels and plastics. The children’s eyes lit up as the iodine solution’s color quickly transitioned from brown to different shades of blue.
SACNAS volunteers then performed a simple chemical reaction utilizing hydrogen peroxide and white vinegar to extract iodine from iodized salt. Following a simplified explanation of the experiment, volunteers had the children observe the staining under a miniature wooden microscope (kindly donated by one of our own). Like true scientists, some of the kids repeated the experiments in awe. Others left the station in excitement telling their parents that they wanted to try this experiment at home.
As the kids shimmied down the table, their excitement steadily grew as their eyes fixated on a fluid that defied the laws of physics. This odd substance is known as a non-Newtonian fluid, or simply Oobleck. The children’s intrigue piqued as the fluid moved and responded opposite to what they expected. Some even came three times to the table to try to decipher the enigma of Oobleck. How can this simple mixture of just cornstarch, water, and food coloring react in such a way? One can only feel inspired as that sparkle of creativity lights up their eyes and one can only hope that this activity had left a lasting impression in some way or another.
After experiencing the magic of a non-Newtonian fluid, the kids worked together with the volunteers to extract DNA from strawberries. As they joyfully smashed the strawberries in a solution of dish detergent, salt, and water, the children quickly learned how every ingredient was vital. They learned how dish detergent helped them dissolve the cell membranes to allow them to gain access to the DNA and how the salt creates an environment that attracts the DNA. Once they added cold isopropanol to the filtered solution, they gazed in amazement as the once invisible matter precipitated into a cloudy mass. Despite some of them already having learned about DNA in school, they were thoroughly excited as this was their first opportunity to see it with their own eyes.
SACNAS’s exhibit concluded with every children’s favorite, balloons. The volunteers asked the kids if they wanted to see, the aptly themed, dancing ghosts. Inquisitively, they quickly replied, “YES.” That was when their journey through static energy began. “Behold the power of static electricity!” the volunteers exclaimed as they vigorously rubbed the balloon against their hair, transferring electrons to the balloon. “Shall we dance?” The balloon was slowly placed near the cutely-shaped ghosts made of tissue paper as they began to rise in a slow waltz from an attraction of opposite charges. The ghosts stood tall for but a brief moment until they steadily returned to their “neutral” position.
In their last experiment exhibiting centripetal force, SACNAS volunteers placed a penny inside a balloon. “What’s the penny for?” the children inquired as they shook the balloon unknowing of its purposes. The volunteer then palmed his hand over the balloon and began to hastily spin it. The penny whirs as it spirals within the rubber walls of its balloon cage. Then suddenly the volunteer stops, but the penny doesn’t stop, it keeps trudging along, trying to find its center. The children fervently follow in suit. How long can they keep it going?
As they move out from the SACNAS table, the kids were welcome by UT Health San Antonio WISDOM organization where they teach kids regarding ocean acidification. WISDOM‘s volunteers were able to tell the importance of reducing CO2 emission since it can affect the life of the organism that lives on it.
Through all these experiments from both organizations, the kids got to be familiarized with chemistry, biology, physics and conservation biology, all of which are important fields in S.T.E.M. that will shape the future of our nation.
“This event strengthened my belief that outreach events like these are very important for kids of all ages to participate. In my opinion, teaching them individual experiments is only secondary to inspiring them to learn more about science and hopefully pursue a career in S.T.E.M. Moreover, the involvement of parents in these events is imperative to sustain their interests in science as they move from one grade to the next,” said Thu Duong, SACNAS communication’s coordinator and graduate student in the Cell Biology, Genetics & Molecular Medicine discipline of the Integrated Biomedical Sciences.