Kate the Chemist: Dragons vs. Unicorns
Page 8
“I’m proud of Kate for figuring out those smoking Cheetos,” said Dad. “It was quite the complex operation.” Dad put his hand on my shoulder. “So, gang, ready for some ice cream?”
“Yes!” cheered Liam.
I scurried away to find Birdie and Elijah and let them know it was ice cream time. It didn’t take a lot of convincing. We all jumped up and down singing. “I scream, you scream. We all scream for ice cream!”
Out of the corner of my eye I could see Avery looking at us longingly.
I raced over to her. “Want to come to McSweeny’s with us?”
Avery looked up at her dads. “Can I?”
“Absolutely, sweetie,” said her dad Mark, who nudged her dad Andrew.
“Better get yourself a double scoop,” said Andrew as he handed Avery a twenty-dollar bill. “We expect change.”
We all left the theater together.
We had our own kids’ table at McSweeny’s. My parents sat in the front of the ice cream parlor on their own little date. I got my cone with a double scoop of salted caramel dipped in chocolate sprinkles, my favorite.
“Want to try mine?” asked Liam. “It’s bubble-gum flavor.”
I shook my head. “No, thanks, I’m good.” I eyed my little brother suspiciously. “It’s not like you to share.”
“I’m so happy!” he cried. “The dragons used magic Cheetos! You know, a whole bag of them appeared in your backpack one morning, just waiting for me to eat them!”
I cupped my hand over my mouth. “Oh my goodness. You ate them before I brought them to school.” The mystery of the missing Cheetos was finally solved.
Liam nodded and licked his drippy cone.
“Told you it wasn’t me,” Avery said, laughing.
Elijah waved his finger. “I’m keeping an eye on you, Liam.”
“Especially with anything involving orange snack food,” said Birdie.
“Next time, just ask first, Liam. Okay? But I can’t blame you. Those were definitely yummy magic snacks.” Then I winked at my friends.
At that moment, I realized something big. Friends, just like polymers, must stick together. They should listen to each other, too. And while science club would always be my favorite thing to do, drama wasn’t so bad either. Especially when chemistry was involved.
UNICORN GLUE
TO MAKE YOUR UNICORN HORN
Get a piece of paper.
Draw a large triangle with a rounded bottom on the paper.
Cut it out.
Roll the paper into a cone and tape or glue it together.
Decorate your unicorn horn.
MATERIALS
1½ cup water
½ cup cornstarch
¼ cup corn syrup
2 teaspoons white vinegar
2 teaspoons food coloring
½ teaspoon glitter
1 unicorn horn
1 medium bowl
1 medium saucepan
Craft sticks
Hot plate or stove top
1 spoon
PROTOCOL
Add all ingredients (except the unicorn horn, bowl, craft sticks, and spoon!) to a medium saucepan.
Heat the mixture over medium-low heat for approximately 7 minutes, stirring continuously.
NOTE: Depending on your heat settings, it may take up to 20 minutes. Be patient!
The mixture will thicken into a frosting-like substance. This is the glue.
Take the saucepan off the heat and allow the glue to cool for 5 minutes.
Transfer the glue to a medium bowl.
Use craft sticks to spread your glue!
HOW IT WORKS:
Glue is extra sticky because it has both adhesive and cohesive forces. When we combine these two properties, we are able to glue anything we want together. Let’s think about an easy example, like gluing a poster of the periodic table to the wall. When a molecule (formed when two or more atoms join together) likes to make bonds with other molecules, we say it has strong adhesive forces. The best glues have extremely strong adhesive forces because they have to stick to both the poster and the wall.
The cohesive forces allow the glue to stick to itself—just like peanut butter stays together in a clump. When a molecule likes to make a bond with itself, it has strong cohesive forces. A perfect glue sample has great adhesive and cohesive forces so that the poster is stuck to the glue and the glue is stuck to the wall (adhesive-cohesive-adhesive).
It’s important to give the glue time to dry before testing its strength. As the molecules from the atmosphere interact with the glue, the water evaporates from the glue mixture. This process forces the glue to harden, activating the “glue” properties we love. The resulting hard glue layer is extremely strong and very difficult to break. The strength of the glue is determined by what it’s made of and what it can stick to.
DR. KATE BIBERDORF, also known as Kate the Chemist by her fans, is a science professor at UT–Austin by day and a science superhero by night (well, she does that by day, too). Kate travels the country building a STEM army of kids who love science as much as she does. You can often find her breathing fire or making slime—always in her lab coat and goggles.
You can visit Kate
on Instagram and Facebook @KatetheChemist,
on Twitter @K8theChemist,
and online at KatetheChemist.com
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