Article
Courtesy of Camryn’s Slime Shoppe

Slime Time

The science behind the popular slime trend

By Jackie Appel
From the February 2023 Issue

Learning Objective: Students will analyze the properties of slime and explain why slime is not classified as either a solid or a liquid.

What can you roll into a tight ball, stretch out into long strings, or let drip through your fingers? You guessed it—it’s slime! Whether bought from stores or made at home, slime is all the rage. But have you ever wondered what slime really is?

Most slime is made by mixing craft glue, water, and a substance called an activator. (At home, people often use baking soda and contact lens solution to make the activator.) When these ingredients are combined, a chemical reaction takes place. Long particles in the glue connect with small particles in the activator. The result is a material that is stretchy, squishy, firm, and fluid all at the same time!

Courtesy of Camryn’s Slime Shoppe

Camryn hosts a slime-making event in North Carolina.

These unusual properties are what make slime fun. Social media is full of videos of people sharing their slime recipes. Some kids have even started their own slime businesses!

Camryn Williams, who is from North Carolina, was 9 years old when she started Camryn’s Slime Shoppe in 2020. She calls herself a slimeologist. Camryn sells slime and slime-making tools through her website. She hosts workshops where she teaches others how to make slime.

Camryn got her start by watching videos of people making slime online. “Making slime is a science,” says Camryn. “Kids get excited about seeing how mixing just a few ingredients can make such a fun toy.”

video (1)
Activities (2)
Quizzes (1)
Answer Key (1)
Step-by-Step Lesson Plan

1. ENGAGE: Make slime and observe patterns in how slime behaves.

  • Prepare for a hands-on investigation: For each group of 4 students, you’ll need one batch of slime. Each group needs ½ cup of washable school glue (about 4 oz), ½ tsp of baking soda, 1/3 cup of water, and 1 tbsp of contact lens solution (about 0.5 ounces). 
  • Materials note: Make sure the contact lens solution includes boric acid and sodium borate. (We used a store brand.) 
  • Use the It’s About Slime hands-on investigation and the “Science in a Snap” video as guides to make slime. Note: Students should wash hands before and after handling slime. If desired, students can wear disposable nitrile gloves while making and handling the slime. Slime can be drippy and sticky—remind students to keep slime over a desk (i.e., away from the floor and carpets). 
  • After students are done, discuss their observations, focusing on patterns they noticed in how the slime behaved at different times. 

2. EXPLORE: Discuss the properties of slime and how they compare with those of solids and liquids.

  • Ask students to list common states of matter. (solid, liquid, and gas) When did the slime act like a solid? (when it was squeezed or pressed) When did it act like a liquid? (When handled gently, it flowed.) What state of matter do they think slime is most similar to? What evidence supports that idea? 
  • To take it further, have students sketch what they think the particles that make up the slime look like when it’s acting like a solid and when it’s acting like a liquid.

3. EXPLAIN: Read an article, featuring a student entrepreneur, all about slime and its properties.

  • Spotlight the article’s opening image on page 18 in Presentation View (available on the left-hand side of the article’s scrollable webpage). Ask questions like: What properties of slime are visible in the photos? (e.g., stretchiness, drippiness, transparency) Does this indicate slime is a liquid or a solid? Let students discuss in pairs. 
  • Read the article, pausing to discuss properties of slime and how the ingredients transformed into something new because of a chemical reaction.

4. EVALUATE: Reinforce core ideas with a low-stakes assessment.

  • Allow students to complete the Quick Quiz. Discuss their responses to the open-ended questions, connecting their experience with slime in step 1 to the sidebar “What Is Slime, Really?” Focus on how the particles that make up slime can have a different structure when slime is being handled differently.

5. EXTEND: Plan and revise a design for a new kind of slime.  

  • Ask students to predict what steps it would take to bring a new slime product to market. Preview the Slime Design activity. Allow students to work independently or in small groups. Have students share their ideas before revising their plan.

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