Episode 17: Inside the Lab- Isotope Marshmallow Activity
Welcome back to the Confident Chemistry Teacher Podcast!
Episode Summary
In this episode, I’m breaking down one of my favorite quick-and-fun isotope activities — the Marshmallow Isotope Lab! This hands-on lab helps students visualize isotopes by building models of hydrogen’s three isotopes using mini marshmallows and toothpicks. It’s simple, colorful, and perfect for reinforcing the difference between ions and isotopes in a memorable way.
I’ll walk you through:
✅ Why this lab helps students truly see isotopes instead of just reading about them 🍬 How to organize the materials (and yes — students can eat the leftovers!)
🧠 Common student mistakes to watch for and how to correct them
✏️ How to use the included reading passage for literacy practice and ACT-style prep
👩🏫 Ways to scaffold the activity so every student participates and learns
⏰ How to fit it into a 30-minute class period You’ll also hear a few updates on my upcoming Confident Chemistry Lab Membership (launching this January!) and a quick peek into my current teaching reality — classroom renovations, freshmen energy, and all.
🧪 Teacher Tip of the Week When introducing ions and isotopes, remind students that: “Ion” is the smaller word — it deals with the smaller subatomic particle (electrons). “Isotope” is the larger word — it deals with the larger subatomic particle (neutrons). This quick mnemonic helps them remember the difference every time!
🧰 Classroom Logistics Recommended group size: 3–4 students Average class time: ~30 minutes Materials: Mini marshmallows (different colors), toothpicks, paper plates Pro tip: Have students bring in marshmallows — saves your budget and builds buy-in!
🔗 Resources Mentioned
👉 Download or view the Marshmallow Isotope Lab HERE
🎧 Listen & Subscribe Catch this episode on Apple Podcasts, Spotify, or Kajabi — and don’t forget to leave a review!
💌 Stay Connected
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