Standing before an audience of more than 200 elementary-schoolers, Rachel Sweeney proudly held up a handmade sign. The problem was, it was blank.
After a few beats, the gathered students clapped encouragingly anyway for the external programs educator for the Maryland Science Center. But then, fellow educator Jacob Hippert sprayed the sign with an indicator, in this case ammonia.
A hidden message appeared in pink ink: “I <3 Science.” The students applauded much more enthusiastically.
This opening demonstration was one of many that Hippert and Sweeney brought to the Friendship Valley Elementary School audience Wednesday. The school’s PTO sponsored the event, which was titled “What’s the Matter,” and is exclusive to the Science Center’s traveling science program.
Samantha Blau, external programs manager for the Science Center, said the center has programs for students from pre-kindergarten through middle school on topics that range from dinosaurs to chemistry to planetary science.
Of the demonstrations like those seen in the chemistry program Wednesday, she said, “They’re flashy, they’re high energy, they’re really showy."
Throughout the program, the educators showed off the way that substances change from one state of matter to another. This might sound dry, but it took the form of bubbling foam, spraying clouds of gas and lots of (safely controlled) fire.
At one point Hippert swirled a flammable liquid until it evaporated into a flammable gas inside a jar. Later, Sweeney combined two liquids to make Sterno, the flammable solid fuel that some might recognize from its use on buffet tables, where it’s used to keep dishes hot.
For the grand finale, the scientists revealed that the balloon behind them on stage was not filled with helium as one might expect, but hydrogen, a much more flammable gas. Hippert used a long lighter to set the balloon aflame.
One souvenir stayed with Friendship Valley after the activity: a pink lump of Polyurethane foam that slowly grew throughout the demonstration as it sat on a table on stage.
Wednesday morning, the substance was still a little “jiggly,” Hippert said, but by the next morning it would be hard as a rock and able to hold the weight of a person standing on it.
Most classroom teachers don’t have the resources to do demonstrations like this, Blau said. Those behind the program hope it is memorable for students, either as something teachers can refer back to for examples in class or as an exciting capstone to a unit.
Each year, the program travels to every county in Maryland as well as surrounding states. Blau said they like being able to come to schools, especially those for whom a field trip to the Maryland Science Center in Baltimore would be expensive or logistically difficult.