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Willmar Middle School students learn that chemistry can be fun

Dr. John Benson of Willmar, a chemistry instructor at Ridgewater College, conducts an experiment Thursday for seventh-grade students at Willmar Middle School. Tribune photo by Ron Adams

Drop a can of Coke into a cylinder of water, and you can watch it sink gently to the bottom.

Drop a can of Diet Coke in, and it will float at the top. It won’t even sink if it’s pushed down. The difference? The 38 grams of sugar in the regular Coke make it denser, and it sinks.

Density was one of the first chemistry lessons Willmar Middle School seventh-grade students learned Thursday morning from Dr. John Benson, a chemistry instructor at Ridgewater College in Willmar.

Benson spent nearly an hour talking about chemistry and demonstrating chemical reactions in the school’s gym. His show helped prepare the students get ready for the chemistry unit they are starting in their life science classes.

Chemistry is fun, Benson told the students, as he began by talking about atoms and how they react with each other.

He explained the need for goggles to protect his eyes, and he pulled out his lab coat to protect his skin and clothing. To show that he was going to have fun with chemistry, he said, he wore is coat tie-dyed in bright colors.

“Things are not always what they seem to be in chemistry,” he told the students.

As an example, he held up a Styrofoam coffee cup and he and the students agreed that it would hold a hot liquid. Then he poured in some acetone, and the bottom of the cup disintegrated.

Benson talked about the three states of matter: solid, liquid and gas. He showed the students how a certain chemical compound can turn water into a solid gel.

To illustrate their need to observe their experiments, he mixed two chemicals that were supposed to make foam. He stirred them up in a small container and said, “This isn’t working. We’ll leave this and go to something else.”

He went on to another experiment, and while everyone was distracted, foam began to grow until it had made a mushroom shape above the container.

“You always have to be watching,” he said. “Watch all the time.”

The experiments that seemed to fascinate the seventh-graders the most were those involving liquid nitrogen, which boils at minus 321 degrees.

Benson placed a raw carrot, a racquetball and a half banana.

He dropped the carrot and it shattered into many pieces. He threw the racquetball against the gym wall and it shattered, too. The banana he used to drive a nail into a board.

Benson said he has been doing the shows for the 15 years he has lived in Willmar. He estimated that he’s talked to about 5,000 young students about chemistry.

With the exception of using liquid nitrogen, many homes would have all the materials he used in some of his demonstrations, he said.

Science teacher Lisa Ruter said the show was a good way to get the students to look forward to chemistry. “They’re excited,” she said as students gathered around Benson’s table before they left for their next classes.

Students Maeve Winter, 12, and Amy Linden, 13, said the show was a lot of fun.

For Amy, picking a favorite part was easy: “I liked the nitrogen a lot.”

Maeve said she had known some of the basic concepts before the show, “but it was interesting to see him actually do it.”

Linda Vanderwerf

I cover education issues for the West Central Tribune and have worked for the paper since 1995. I have worked in journalism since 1981.

Follow me on Twitter: @lindavanderwerf

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