Episode 23: Inside the Unit- Moles | Teaching Conceptual Thinking and Math Skills

Episode Intro

In this episode of The Confident Chemistry Teacher Podcast, I’m taking you inside my mole unit — not as a day-by-day plan, but through the thinking and teaching decisions behind it. The mole unit is one of the first truly skill-heavy units students encounter in chemistry, and it can feel overwhelming for both students and teachers.

I share how I introduce the mole conceptually, how I scaffold practice, how I check for mastery along the way, and how I help students build confidence before the test.

My goal is always the same: helping students actually learn chemistry, not just survive the unit.

Key Takeaways

By the end of this episode, you’ll hear how to:

• Frame the mole as a skill-based unit, not a memorization unit
• Help students visualize the scale of the mole before jumping into math
• Scaffold mole conversions so students don’t shut down
• Balance independent practice with more active, collaborative practice
• Use mastery checks to guide instruction before the unit test
• Reinforce the importance of showing work and using units

How I Introduce the Mole Unit

I begin the unit by helping students understand scale. Before touching conversions, I want them to grasp how large Avogadro’s number really is. I use a short video, How Big Is the Mole?, to help students visualize scale.

We discuss why chemists need a way to count particles they can’t see. I connect atomic mass units to grams to show why mass is the bridge between the microscopic and real-world chemistry. To make this concrete, I use a “measuring by mass” activity with paperclips, which helps students understand how counting by mass works in a tangible way.

Teaching & Practicing Core Mole Skills

Even though this is a math-heavy unit, I rely on explicit modeling through Google Slides. My slides focus on how to think through problems, not just the answers. I typically teach skills in this order:

• Molar mass Mole-to-gram and gram-to-mole conversions Moles to representative particles and liters
• Multi-step (double conversion) problems
• Percent composition, empirical formulas, and molecular formulas

Throughout the unit, I remind students that dimensional analysis is a tool, not a trick — something they already know how to use.

Practice: Boring Practice + Fun-ish Practice

Because chemistry skills require repetition, I intentionally plan for both types of practice.

Independent practice:

• Worksheets for building confidence
• Quiet work time so students can’t rely on neighbors

Active or “fun-ish” practice:

• Rock–Paper–Scissors review
• Whiteboarding
• Small-group and partner practice
• Practice tests in mixed-ability groups

This balance supports both skill mastery and student engagement.

Mastery Checks (Before the Test)

Instead of waiting until the unit test to find gaps, I use short mastery checks throughout the unit. Each mastery check is only a few questions.

Students receive feedback quickly.

Retakes are built in when students show effort

These checkpoints:

• Create urgency
• Prevent last-minute cramming
• Help me adjust instruction with warm-ups, extra practice, or short videos

Labs & Hands-On Learning

Labs in the mole unit help students connect math to real substances. Some of my favorites include:

• Counting by measuring mass (early in the unit)
• Avogadro and the Mole lab using real substances

Extension activities like Mole Olympics or sewing a mole These activities don’t replace instruction — they enhance understanding and make the unit more memorable.

Assessment & Grading Philosophy

My assessments are a mix of multiple choice and free response, with a strong emphasis on showing work.

I use a consistent grading approach:

• Credit for showing work
• Partial credit for reasonable answers
• Points for units and significant figures

Using the same expectations from the start helps students understand what matters and builds confidence over time.

Final Takeaway

The goal of the mole unit isn’t just passing a test — it’s helping students believe they can do hard, skill-based chemistry.

When students leave this unit knowing they can:

• Set up conversions
• Use units correctly
• Explain their thinking

…it sets them up for success in stoichiometry and beyond.

Closing

As always, thank you for listening to today’s episode. Teaching chemistry can feel overwhelming, and my hope is that this episode gave you one idea, one strategy, or one small shift you can take back to your classroom. If you found this episode helpful, please share it with another chemistry teacher who might need some encouragement. And until next time — keep inspiring, keep experimenting, and keep being awesome in your chemistry classroom. Happy teaching.

🧪 Mole Unit Resources (Optional Support)

If you’re teaching the mole unit right now and want some ready-to-use resources, here are a few free activities and some from my Teachers Pay Teachers store that align with what I shared in this episode:

• Measuring by Mass Activity (Paperclip Model) (Free) – helps students understand how chemists count particles using mass.

• Mole Conversion Google Slides Presentation– includes step-by-step directions for solving mole problems, fill-in notes, and 5 short video lectures.

• Mole Conversion Worksheets, Quizzes, and Warm-ups – structured practice and quick assessments to build confidence before the test.

(Use what works for your classroom — these are simply tools I use to support the strategies discussed in this episode.)