Home›Lesson Plans›Science›Chemistry · Grade 10

The Mole & Molar Mass

Tenth graders learn the mole — chemistry’s counting unit (6.02 × 10²³ particles) — and how to calculate molar mass by summing atomic masses, the bridge between the atomic world and grams we can weigh.

Grade 10Quantitative Chemistry55 minutes1 class period5E ModelExplicit teaching4 StandardsNGSS
Start the Lesson
Assign or share this lesson

Copy link works with Canvas, Schoology, Moodle and any other LMS — paste it in as a resource or assignment.

Lesson at a Glance

Everything you need before the bell rings

Learning Objectives

Students will be able to…

  • ✓Explain the mole.
  • ✓State Avogadro’s number.
  • ✓Calculate molar mass.
  • ✓Connect moles to grams.
Essential Question

Atoms are far too tiny to count one by one — so chemists count them in “moles.” What is a mole, and how does it let us weigh out an exact number of atoms?

0
Lesson Phases
0
Vocabulary Terms
0
Standards Aligned
0
Interactive Task
Explore · Interactive

The Mole Check

Project each item and have students answer about moles and molar mass. The tool explains Avogadro’s number and molar-mass math.

⚖️ Understand the mole & molar massTry it
Answer each question about the mole.
The Lesson · 5E Instructional Model (Engage · Explore · Explain · Elaborate · Evaluate)

55 minutes, five moves

Tap any phase to open the teacher moves and student actions.

1

Engage — Counting the Uncountable

5 min

Atoms are too tiny to count — so how do chemists count them?

👩‍🏫 Teacher Moves

  • Pose the counting problem.
  • Introduce the mole.
  • Pose the question.

🎒 Student Actions

  • See the problem.
  • Meet the mole.
  • Predict the idea.
2

Explore — Explore the Mole

12 min

Students investigate.

👩‍🏫 Teacher Moves

  • Send students to The Mole Check.
  • Note Avogadro’s number.
  • Note molar-mass math.

🎒 Student Actions

  • Answer them.
  • Note the number.
  • Note the math.
3

Explain — Moles & Molar Mass

13 min

Students explain.

👩‍🏫 Teacher Moves

  • Explain the mole as a count.
  • Calculate molar mass.
  • Connect moles to grams.

🎒 Student Actions

  • Explain the mole.
  • Calculate mass.
  • Connect grams.
4

Elaborate — Weigh It Out

15 min

Students elaborate.

👩‍🏫 Teacher Moves

  • Find the molar mass of a compound.
  • Convert grams to moles.
  • Apply to a real amount.

🎒 Student Actions

  • Find molar mass.
  • Convert units.
  • Apply it.
5

Evaluate — Evaluate

5 min

Students conclude.

👩‍🏫 Teacher Moves

  • Explain the mole.
  • Calculate a molar mass.
  • Hand out the exit ticket.

🎒 Student Actions

  • Explain it.
  • Calculate it.
  • Complete the exit ticket.
Standards Alignment

Built to the standards you report on

Aligned to the Next Generation Science Standards (High School Physical Science / Chemistry).

NGSS
HS-PS1-7

Use mathematical representations to support the claim that mass is conserved (moles/stoichiometry).

NGSS
HS-PS1-2

Construct explanations for chemical reactions.

NGSS
HS-PS1-3

Plan investigations of substance properties.

NGSS
SEP-5

Using mathematics and computational thinking.

Differentiation

One lesson, every learner

Multilingual Learners

ELL / EMERGING READERS
  • Molar-mass worked examples.
  • Sentence frame: “One mole = ___ particles.”
  • Use a periodic table.

Support & Access

IEP / 504
  • Start with counting analogy (dozen).
  • Add atomic masses step by step.
  • Use a periodic table.

Stretch & Extend

GIFTED / EARLY FINISHERS
  • Convert grams ↔ moles ↔ particles.
  • Find molar mass of complex compounds.
  • Introduce stoichiometry.
Materials

What to gather

  • 📽️Projector / board
  • 🧪A balance
  • 💻The Mole Check
  • 📊Periodic tables
  • 🧮Calculators
  • 🎫Exit-ticket slips
Vocabulary

Key terms — hover for a quick definition

mole6.02 × 10²³ particlesAvogadro’s number6.02 × 10²³molar massthe mass of one mole (g/mol)atomic massthe mass of one atom (from the periodic table)formula massthe sum of atomic masses in a formulaparticlean atom or moleculegrama unit of massconversionchanging between units
Evaluate

Exit Ticket

Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.

QUESTION 1
How many particles are in one mole?
6.02 × 10²³ (Avogadro’s number).
QUESTION 2
How do you find the molar mass of a compound?
Add up the atomic masses of all the atoms in its formula.
QUESTION 3
What is the molar mass of CO₂? (C = 12, O = 16)
44 g/mol (12 + 16 + 16).

Elaborate: grams to moles.

Have students convert a mass in grams to moles (and to particles) using molar mass and Avogadro’s number. A printable mole sheet is in the Science library.

Study · Flashcards

Study the key terms

Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.

🃏 The Mole & Molar MassFlip
Card 1
Term
Tap to flip →
Meaning
0

Nice work!

Practice · Quiz

Check your understanding

A quick self-check with instant feedback, drawn from this lesson’s key terms.

📝 The Mole & Molar MassQuiz
Score: 0
1 / 6
Question 1
0%

Nice work!

Practice · Worksheet

Printable worksheet

A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.

🖨️ The Mole & Molar MassPrint
Name: ________________________
Date: ____________

Part A · Write the word that matches each meaning

Word bank: atomic mass, Avogadro’s number, conversion, formula mass, gram, molar mass, mole, particle
  1. an atom or molecule
  2. 6.02 × 10²³
  3. the mass of one mole (g/mol)
  4. changing between units
  5. 6.02 × 10²³ particles
  6. the sum of atomic masses in a formula
  7. the mass of one atom (from the periodic table)
  8. a unit of mass

Part B · Show what you learned

  1. How many particles are in one mole?
  2. How do you find the molar mass of a compound?
  3. What is the molar mass of CO₂? (C = 12, O = 16)
Answer key — Part A: 1) particle · 2) Avogadro’s number · 3) molar mass · 4) conversion · 5) mole · 6) formula mass · 7) atomic mass · 8) gram
Part B: 1) 6.02 × 10²³ (Avogadro’s number). 2) Add up the atomic masses of all the atoms in its formula. 3) 44 g/mol (12 + 16 + 16).