Community outreach inspires interest in STEM for kids

Graduate students and postdocs led an afternoon of hands-on science activities and fun for students grades 3-8 in the hallways and labs of Penn Chemistry.

people around a bowl of steamy liquid nitrogen
Students took turns helping stir the liquid nitrogen ice cream as graduate student volunteers explained some of the extremely cold liquid’s unique properties.

Last Saturday, the hallways and labs of Chemistry 1973 were the setting for an engaging STEM educational experience for children in the Greater Philadelphia community. 

Activities for Community Education in Science (ACES), founded by Penn chemistry graduate students in 2014, aims to inspire interest and provide a positive outlook in STEM for kids and their families. The biannual event provides students grades 3–8 with an afternoon of demonstrations, experiments, and hands-on activities focused on physics and chemistry. 

After an explosive opening demonstration, more than 70 students made their way between experiments in small groups, each participating in different experiments based on their age. 

students in a laboratory
Using homemade cereal box spectrophotometers, students got to see how gold nanoparticles absorb a portion of the light spectrum. 

Older students in grades 6-8 got to create gold nanoparticles and learned about electromagnetic light waves using homemade spectrophotometers. Volunteers explained how spectrophotometers split light into different colors based on wavelengths. The young participants then studied their own nanoparticle solutions to see what parts of the spectral rainbow were being absorbed.

The students also learned how to make gel electrophoresis, a technique used in the lab to study DNA. Students were guided as they made agarose gels and loaded samples into the wells with care and precision. 

students in a lab looking at filter paper
Younger students learned how scientists use color to study chemical solutions, such as using red cabbage to find out if something is an acid or a base.

Younger participants in grades 3-5 learned how scientists use color to study chemistry by seeing how red cabbage could be used to determine if a solution is an acid or a base, watching lithium chloride and potassium chloride change color in the flame of a Bunsen burner, and creating artwork that changed color under UV light. They also learned about Newton’s laws of motion by making their own balloon-powered cars to race across the room—much to the enjoyment of both the students and the volunteers. 

But it’s not just about learning facts and doing experiments. Drew Newman, a third year graduate student, says that the experiments like the balloon-powered car are also meant to help students be creative, and to try new approaches as they assemble their cardboard cars. 

That was also one of the goals for the spaghetti tower event, where groups of both younger and older students are asked to build a tower using only marshmallows and uncooked spaghetti. Volunteers provide advice on how to make a tall yet stable tower without giving them too many specific instructions. Students worked together in teams while also thinking creatively about how to approach the problem, just like what research scientists do in the lab. 

people building a triangle-shaped tower out of spaghetti and marshmallows
Students had to get creative when given the task of assembling the tallest tower they could using only spaghetti and marshmallows, with volunteers available to offer advice and a spare hand.

On the warm afternoon, everyone enjoyed the liquid nitrogen ice cream demonstration. Volunteers discussed some of the unique properties of this incredibly cold (-321 degrees Fahrenheit) liquid and showed the students and their families how liquid nitrogen can turn delicate rose petals into brittle shards. In between sampling ice cream, students asked questions and were amazed at all the incredible things liquid nitrogen could do. An endless chorus of “That’s so cool!” was the most common, and most accurate, exclamation. 

Nearly 30 volunteers, most of whom are graduate students and post-docs from chemistry and engineering, led small groups of students at each experimental station, explaining the science behind what they were doing while sharing their own enthusiasm for physics and chemistry.

Philip Gilmartin, a fourth year graduate student and ACES board member, says that all of the volunteers take pride in what they do. “Interacting with the kids is enlightening,” Gilmartin says. “As graduate students, we are in the nitty gritty of our work, so it’s fun to take a break from that and do more approachable science.” 

Cheyenne Chaplain, a third year graduate student and member of the ACES Board of Directors, finished off the day with a set of awe-inspiring demonstrations. Students and their families gather around her table in the shade just outside Smith walk as she asks if the students had a good time. Her question was met with a chorus of shouts of excitement as the students shouted what their favorite experiments were. 

After picking up a dollar bill with massive tongs and dipping it into a beaker filled with rubbing alcohol and water, she told the group she was going to light it on fire. “You’re crazy!” a student yells from the crow. A second volunteer ignites the bill, with the fire burning quickly and leaving the bill unscathed. Chaplain explains that since the rubbing alcohol is more flammable, it protects the money since it burns off more quickly. 

She then fills up a large plastic tub with liquid nitrogen and asks the group to share what they learned about this super liquid. “It’s really, really, really cold, but not frozen” another participant replies. She then pours hot water into the tub to make a “homemade” thunderstorm and stands back as it bubbles and thunders while the crowd cheers with excitement. 

a cloud emerging from a plastic container full of dry ice
Students gathered outside near Smith Walk for a series of final demonstrations, including a dry ice “thunderstorm.” 

As students and their families made their way home, armed with bright blue backpacks filled with activities to work on at home, the ninth iteration of ACES closed out a successful event. One testimonial from a first-time attendee said that they had a great experience and would definitely return in the fall. 

“That’s what this is all about,” the ACES Board says. “It’s an honor and a privilege to be able to host this free event for our local community, and we hope we can continue to foster an interest in science in all students who attend the program.”

Photos by Phil Gilmartin.

Activities for Community Education in Science (ACES) is supported by the Department of Chemistry, Pharm4Good, Dow Chemical, Fisher Scientific, and a grant from the Graduate Student Government of the School of Arts and Sciences. Additional support was provided by the Graduate and Professional Student Assembly, Penn Women in Chemistry, and the American Chemical Society.