Seven first grade students crowded around the table, staring intently at Payson High School (PHS) sophomore Natalia Olivares and junior Jessica York.
“Have you ever seen soap?” Olivares asked the students.
“Yes,” they answered together.
“Do you use a microwave at home?” asked York.
“Yes,” they answered.
“Well, watch what happens when I put this bar of soap in the microwave,” said York.
She placed the soap on a plate and turned the microwave on high for 30 seconds. The PES first-graders crowded forward so only a few could see, backed up at York’s orders, then helplessly crowed forward again — lured by their curiosity. They gasped in unison as the soap bubbled up into a pile that looked like shaving cream.
“Come check out what this feels like,” said York. “It feels like it has air inside.”
The children politely lined up to rub flakes of soap between their fingers.
“Ooooo,” said many of them, “this feels cool!”
The PHS and Payson Elementary School (PES) students spread out in the Wilson Dome to participate in a chemistry expo created by PHS chemistry teacher Meena Rustagi. For the second year, Rustagi has organized her students to put on demonstrations for first-graders — all in hopes of proving that chemistry is cool.
“I want them to have the responsibility to be a teacher right now,” said Rustagi of her high school students. “They’re doing great. I’m so proud of them.”
“It’s much easier for kids to learn from kids,” said Leslie Reisdorf, a first grade teacher from PES.
And the near-hero-worship the first-graders accorded the high schoolers illustrated Reisdorf’s point.
Rustagi had all of her chemistry classes come up with a demonstration of a concept in chemistry that would hold the attention of a 7-year-old. As a result, more than 20 tables lined the walls of the PHS basketball court in the dome.
“It took them two months of work,” Rustagi said. “I had them write a rough draft of their concept, including the materials they would use and everything.”
York and Olivares said Rustagi helped them decide on the experiments to show Charles’ and Boyle’s laws.
Back at the table, the girls explained why the soap bubbles blew up, as the kids listened with interest. “The soap in the microwave shows Charles’ Law,” said York.
The law, first discovered by Jacques Charles in the 1780s, explains how gas molecules react to increasing the temperature.
York explained that the air molecules between the soap molecules spread out as the microwave made the soap hotter. This expanded the soap into the shaving cream-like texture.
A hot air balloon could also illustrate how Charles’ Law works.
As the balloon operator heats up the air in the canvas, the space between the molecules increases inflating the balloon. It floats because the air inside the balloon weighs less than the air outside the balloon.
“Charles’ Law says that if the air in a substance is heated, the air molecules move faster and faster,” said York.
The PES students nodded, then waited for the next experiment because the high school girls had a second microwave.
“Who has ever seen or touched a marshmallow?” asked York.
Every student’s hand shot into the air.
“Big or small marshmallows?” asked Olivares.
“Big!” they said in unison.
Olivares put a Peeps blue-colored sugar-covered marshmallow chick in the microwave to demonstrate Boyle’s Law.
“It’s blowing up like a monster!” said one first-grader. The blue sugar cracked and spread, looking more and more like elephant skin.
However, when the high school girls pulled the marshmallow out of the microwave, it promptly deflated.
“It was really big, so why is it really small now?” asked York.
The first-graders looked at the blue sugar mess completely stumped. No one knew what to say.
“This shows Boyle’s Law,” said York. “He discovered that when the pressure is released, the object decreases in size.”
Another way to understand Boyle’s Law is to think of a party balloon full of helium. If it is released, it floats up in the sky because helium is lighter than air.
Yet, once it gets into the upper atmosphere where the air pressure is lower (because the Earth’s atmosphere disappears in space), the helium expands until it pops the balloon.
The marshmallow showed a less intense example of deflation than the popping balloon.
Olivares and York made an impression. Charles Cram, a first-grader in Reisdorf’s class said he liked that table the best.
“I like it cause we got to see how stuff absorbs, like the soap,” he said. “It just peeled up because air bubbles absorb heat and went up.”
Charles said his favorite subject in school is science.
He would warm Meena Rustagi’s heart.