Garrett Neese/Daily Mining Gazette Ed Laitila, a materials science assistant professor at Michigan Technological University, pours liquid nitrogen for Houghton Middle School students Luke Hill, Matthew Guilbault, Brett Gaff and Katie Sarau as they make ice cream during the annual Day of Science Wednesday.

By GARRETT NEESE

Houghton Daily Mining Gazette

HOUGHTON — From purifying water to learning the reactions creating ice cream, Houghton Middle School seventh-graders got hands-on learning as part of the school’s annual Day of Science activity at Michigan Technological University.

About 120 students took in four stations out of 11 throughout the day, intended to engage them in various science, engineering, mathematics and technology (STEM) fields.

In Ed Laitila’s session, the materials science assistant professor taught students about the properties of matter and how it shifts between states.

“When we put that nitrogen in there, it’s going to transform into a gas and it needs energy,” he said. “It’s going to pull that energy out of the cream. And if you pull energy out of the cream, what happens to the temperature?”

“It goes down,” students replied.

“It goes down, until it starts solidifying,” Laitila said.

Students mixed ingredients with a metal whisk to distribute them evenly. Once the liquid nitrogen was added, they switched to a wooden spoon to avoid conducting heat energy.

Cecelia Butler had liked all the events. Hers included crushing concrete to test its strength, as well as a study of water purification with methods like charcoal and sand.

“It’s really cool to see what actually comes out of the water,” she said. “It’s pretty disgusting, though.”

In Chloe Hohnholt’s favorite activity, students put their hand in ice and found what happened to their heartbeat and blood pressure.

Each subject was more complicated then she knew going in, Hohnholt said. But that made it interesting.

“There’s always something new to learn,” she said.