Fire! Ice! Explosions!
An up close and personal chemistry lesson had third- and fourth- grade Williamsport Area School District gifted students on the edge of their seats last week as they watched Lycoming College chemists compile mixtures and perform experiments that showed that science is fun and full of possibility.
The field trip to the college was part of the gifted support science class that recently completed a unit on forensics and investigation.
Dr. Charles Mahler kicked off the demonstration by soaking a racquetball in liquid nitrogen and asking students to guess what would happen to the ball.
When he bounced the ball, it made a loud knocking sound on the table, as if it were made of glass. The second time he bounced the ball, it smashed into pieces.
"Chemists do experiments because you never know what's going to happen when you do the experiment," he told the students. "I've done this experiment lots of times and I've never had (the ball) bounce like that before."
Another experiment, dubbed "The Elephant's Toothpaste," showed students the way chemicals can react to one another. Mahler mixed lemon-scented dish detergent, hydrogen peroxide, food coloring and potassium iodine in a large glass tube to create a fictional toothpaste for elephants. When he added the potassium iodine to the mixture, foam quickly shot up out of the tube and spurted for several seconds, creating a pile of foamy lemon-scented bubbles. Mahler explained that the potassium iodine was an enzyme creating a catalyst.
A student favorite was "The Exploding Pringles Can," in which Mahler used hydrogen gas to ignite a flame inside a Pringles can. Students held their hands over their ears in anticipation of the "boom!" that resounded throughout the room, and eagerly passed around the still-warm Pringles can after the explosion.
Mahler told students the explosion created by the experiment is the same reaction that occurs in a vehicle with gasoline.
"Someday you might drive a car that is powered by hydrogen gas burning instead of gasoline burning ... and if you do, that's the kind of explosion will happen inside the car," he said.
Dr. Jeremy Ramsey performed a "magic trick" for students: he dipped a piece of paper in water and then put it in a flame, but the paper didn't burn; then he dipped the wet paper in a "magic solution" and held it in the flame again. This time, the paper burned, but then the fire quickly went out. Ramsey had students guess at the magic solution and then told them it was ethanol.
"Ethanol is very flammable ... and water likes to absorb heat," Ramsey said. "When the water absorbs the heat, it protects the paper and keeps it from getting burned."
In another messy experiment, Ramsey added Mentos to a bottle of diet soda and students watched the soda shoot into the air.
He explained that the Mentos create pressure in the soda, causing the carbon dioxide to be released. Once the soda shoots out of the bottle, all the carbon dioxide is gone and the soda becomes flat.
Ramsey said the texture of Mentos is perfect for the experiment.
"Bubbles like to form on rough surfaces," he explained. "Mentos have a really rough surface, so they work really well."
Ramsey said students could try the experiment at home in their backyards, and suggested trying different types of candy and soda.
After taking a tour of some of the chemistry classrooms and laboratories, students got a chance to get hands-on chemistry experience.
"You don't just get to watch; you actually get to do some of the experiments," Ramsey said.
The students conducted an experiment that Mahler called "Chemistry in a Ziploc Bag."
Students placed two spoonfuls of bicarbonate in the bag, followed by a spoonful of calcium chloride (also known as ice melt).
Next they filled a dropper with a mixture of water and red food coloring and placed the dropper in the bag. At the same time, students squeezed the liquid out of their droppers and shook their bags to mix the chemicals.
"Then you need to make observations," Mahler said.
Student observations included the fact that the powder turned into "big chunks"; that it became "foamy"; and that "It sizzles!"
Mahler's last trick was to pour the mixture from one of the Ziploc bags out over a candle flame; the powder chunks immediately turned to gas and floated upward.
"It's making carbon dioxide gas," he explained to students.
Elementary Gifted Support Teacher Anna Rader said students were ready to try experiments on their own after leaving the college.
"We are so grateful to have had professors at Lycoming College, willing to share their expertise with our students," she said. "After learning about the importance of investigation, our students experienced real-life application of the scientific method. Students left Lycoming excited about learning, and eager to do more experimenting!"