With the enthusiasm of a thespian and the brains of a chemist, “Radioactive” Rachel Dexter wowed a group of children Tuesday night with color-changing chemicals, explosions and a giant dinosaur sneeze.
As part of the Douglas County Public Library’s summer reading program, Mad Science Las Vegas took science to a new level.
“A lot of schools lack the funds to give science classes, so we make science fun for young children,” Dexter said. “The more exciting it is, the more kids will want to do it when they’re older. It’s about putting on a show and telling them fun facts.”
For her first experiment, Dexter defied gravity by twirling a plastic cup, she called Bob, filled with water on a flat disc like a lasso without spilling a drop.
“There are two things that keep Bob in place, friction and centripetal force,” Dexter said. “With the extra weight of the water, Bob stays on by avoiding friction, and centripetal force happens when the water pushes on the cup, and the cup pushes on the disc.”
For her next three experiments, Dexter demonstrated how various chemicals react with each other.
First, she mixed Vitamin C in with Iodine, and it turned the liquid clear. Then, she mixed liquid starch with Hydrogen Peroxide and added it back into the first mixture which turned it black.
“What we had there was a really weird chemical reaction,” Dexter said. “There was a battle between Vitamin C and Iodine, and as you can see our water turned black.
To demonstate how bases, such as toothpaste and toilet bowl cleaner, and acids, like vinegar and apple cidar, react, Dexter mixed Phenolphthalein with water and it turned pink. She then poured the pink liquid into a pitcher of water and it turned clear again.
“Phenolphthalein only changes color when it touches another chemical it recognizes,” Dexter said. “Phenolphthalein loves one type of chemical, a base. It will never change color for an acid.”
As Dexter prepared for her next experiment, she donned orange safety glasses before mixing a 30 percent Hydrogen Peroxide solution with Manganese Dioxide.
“If you’ve ever seen the movie ‘Aladdin,’ he finds a genie inside a lamp,” Dexter said. “We’re going to summon our science genie.”
And with that, a plume of steam poured out of the beaker.
“All that stuff that came out of there was completely harmless,” Dexter said. “That stuff was boiling water. When Hydrogen Peroxide breaks apart it turns into water and oxygen.”
For her next explosion, Dexter poured green food coloring into the 30 percent Hydrogen Peroxide solution. For the final ingredient, she added crystalized Potassium Iodine.
As she dropped the white crystal into the beaker, green foam and steam continuously poured out of the top for close to a minute making a mess on Dexter’s table.
“It looks like elephant toothpaste,” Dexter said.
Dexter also made a Polyurethane mixture that expanded and hardened inside a plastic glove.
Sophia Arthurs, 7, helped mix the ingredients for the first Iodine experiment.
“It was cool how it changed different colors,” she said. “I like that you can do different stuff to make explosions. My favorite part was when the hand turned solid.”
As Dexter explained her final experiment, the dinosaur sneeze, all the boys in the audience moved closer to the stage.
Dexter attached a Carbon Dioxide canister to the end of a water-filled tube, and as she punctured the canister water shot out of the tube and sneezed all over the audience.
Max Dillworth, 10, said he dabbles in science at home.
“I like science. I make my own shampoo and conditioner,” he said. “This makes me like science more because it shows you all the different things you can do with science.”
For more information, visit www.madscience.org.