Eighth graders got the scoop on liquid nitrogen in science class at Battle Ground Middle School. Teacher Kimberly Keesling demonstrated how the element works through a series of experiments that ended with ice cream.
“Liquid nitrogen is really cold and can freeze things instantly,” says student Isaac Wendt. His favorite experiment was watching what happened when Keesling dipped an inflated balloon into a canister of liquid nitrogen. “It just went flat. Then, when she placed it on the desk the shriveled balloon expanded back to its original shape.”
Another lesson involved immersing a bouncy ball into the container. Keesling removed the ball and surprised the students when she tossed it on the floor. It didn’t bounce. It shattered.
“I was shocked,” says student Rafael Lopez. “It's like the outer layer was frozen and it just completely shattered.”
Keesling hopes the lab activity helps students better understand states of matter and the changes in those states of matter: “I would like for them to have made the connection about how the particles respond to the various changes in state of matter based on temperature change. Also, that the temperatures in which this happens vary by elements and their properties, which connects back to the properties from the periodic table.”
The demonstrations helped students visualize their science lesson, but they could taste the final experiment. A cloud of vapor came pouring out of the metal mixing bowl as Keesling added liquid nitrogen to the ingredients (whole milk, half and half, granulated sugar and vanilla). After a few minutes of stirring, the students sampled ice cream.
“It tasted like vanilla ice cream like you buy at the store,” says student Johanna Karcher. “It was an interesting experiment and super neat to see how it worked.”
“The ice cream was good,” added Rafael. “It was a lot softer—just the way I like it.”