Units / Unit A

The Mole and Conservation of Mass

Avogadro's number, mole calculations, link to balanced equations (A-GO3-SO8, SO9).

Long-form student guide · Alberta Science 10 POS · teaching resource (not a cram sheet)

← Back to slide-by-slide view

Outcome checklist

Alberta Program of Studies — tick each row when you can explain it without the slide.

A-GO3-SO8
By the end of this lesson you should be able to: Define the mole as the amount of an element containing 6.02 × 10^23 atoms (Avogadro's number) and apply the concept to calculate quantities of substances made of other chemical species (e.g., determine the quantity of water that contains 6.02 × 10^23 molecules of H2O)
Self-check: Without looking at your notes, give one example or explanation that shows you meet A-GO3-SO8.
A-GO3-SO9
By the end of this lesson you should be able to: Interpret balanced chemical equations in terms of moles of chemical species, and relate the mole concept to the law of conservation of mass
Self-check: Without looking at your notes, give one example or explanation that shows you meet A-GO3-SO9.
A-GO3
Big idea: Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier's law of conservation of mass
Self-check: How does today's lesson connect to A-GO3?

Where this shows up later

Unit B — Energy in changes: Chemical bonds store energy transferred in reactions.

Glossary

mole: The SI amount unit: 6.02 × 10²³ particles (Avogadro constant).
Avogadro's number: Key vocabulary for this lesson (Avogadro's number). Use your class notes and the slide explanations to state it in your own words — Alberta Science 10 expects you to use this term correctly in context.
molar mass: Key vocabulary for this lesson (molar mass). Use your class notes and the slide explanations to state it in your own words — Alberta Science 10 expects you to use this term correctly in context.
coefficient: Key vocabulary for this lesson (coefficient). Use your class notes and the slide explanations to state it in your own words — Alberta Science 10 expects you to use this term correctly in context.

Lab and demo watch-outs

Classroom safety
Follow school rules for equipment, goggles, and fire safety even during thought experiments.
Any time hands-on work is suggested.

Lesson walk-through

Slide 1 · Hook

Counting atoms without counting

Chemists use the mole like dozens — but for particles.

Core explanation

We start with a real situation: Chemists use the mole like dozens — but for particles. Your job is to notice evidence and ask questions before memorizing definitions.

Check your understanding

Can you connect this slide to something we learned earlier today?

Explain moreDeeper teaching notes — read like a tutor explaining the idea

Unit A — The Mole and Conservation of Mass: The mole connects measurable mass to particle counts in balanced ratios. On this slide («Counting atoms without counting»), the science story is: Chemists use the mole like dozens — but for particles. Read like a tutor: connect each bullet to evidence or a model, not memorized wording. Alberta Science 10 expects you to explain ideas in class discussions and written work — this slide supports outcomes A-GO3-SO8, A-GO3-SO9.

Worked example(s)Step-by-step reasoning, not just answers

Apply: Counting atoms without counting
1. State the core idea: Chemists use the mole like dozens — but for particles.
2. Link to a second point: Chemists use the mole like dozens — but for particles.
3. Give one Alberta or daily-life example that fits both ideas.
4. Check your example against the slide — would your teacher agree?
Why this works: Application proves understanding beyond repeating bullets.

Common mistakes to avoid

Mole is a mass or a volume.
On «Counting atoms without counting», use the slide model and vocabulary (mole, Avogadro's number, molar mass, coefficient) to replace this idea.

Try it yourself

Teach «Counting atoms without counting» aloud in 60 seconds using two bullets and one vocabulary word from mole.

Slide 2 · Learning intent

Outcomes

A-GO3-SO8 define mole and Avogadro's number.
A-GO3-SO9 interpret equations in moles; link to conservation.

Core explanation

This slide lists what you are learning today (Outcomes). Your teacher will map each bullet to the Alberta Program of Studies—these are the ideas your class must cover, not extra trivia.

Check your understanding

Can you connect this slide to something we learned earlier today?

Explain moreDeeper teaching notes — read like a tutor explaining the idea

Outcomes — A-GO3-SO8 define mole and Avogadro's number. A-GO3-SO9 interpret equations in moles; link to conservation. Connect this slide to 'The Mole and Conservation of Mass' and to outcome A-GO3-SO8. If anything is unclear, write a specific question for your teacher — vague 'I don't get it' is harder to help.

Worked example(s)Step-by-step reasoning, not just answers

Think through: Outcomes
1. Restate the main idea in your own words: A-GO3-SO8 define mole and Avogadro's number.
2. List one observation or fact that supports it.
3. State one question you still have.
Why this works: Science 10 rewards clear reasoning, not only recall.

Common mistakes to avoid

Mole is a mass or a volume.
Use the evidence and vocabulary on this slide ('Outcomes') to replace the incorrect idea with the class model.
Treating outcome codes as labels to ignore.
Paraphrase each outcome in everyday language — that paraphrase is what you should be able to explain on your own.

Try it yourself

Explain 'Outcomes' to an imaginary classmate using at least two bullet ideas from the slide.

Slide 3 · Concept

The mole

1 mol = 6.02 × 10^23 particles (atoms, molecules, formula units).
POS example: water containing Avogadro's number of molecules.

Core explanation

The mole: 1 mol = 6.02 × 10^23 particles (atoms, molecules, formula units). POS example: water containing Avogadro's number of molecules. In class your teacher will expand on this; use these notes to recall the main science ideas.

Check your understanding

In your notebook, restate the main idea in one sentence without looking.
Name one new vocabulary word and define it in your own words.

Explain moreDeeper teaching notes — read like a tutor explaining the idea

Unit A — The Mole and Conservation of Mass: The mole connects measurable mass to particle counts in balanced ratios. On this slide («The mole»), the science story is: 1 mol = 6.02 × 10^23 particles (atoms, molecules, formula units). POS example: water containing Avogadro's number of molecules. Read like a tutor: connect each bullet to evidence or a model, not memorized wording. Alberta Science 10 expects you to explain ideas in class discussions and written work — this slide supports outcomes A-GO3-SO8, A-GO3-SO9.

Worked example(s)Step-by-step reasoning, not just answers

Apply: The mole
1. State the core idea: 1 mol = 6.02 × 10^23 particles (atoms, molecules, formula units).
2. Link to a second point: POS example: water containing Avogadro's number of molecules.
3. Give one Alberta or daily-life example that fits both ideas.
4. Check your example against the slide — would your teacher agree?
Why this works: Application proves understanding beyond repeating bullets.

Common mistakes to avoid

Mole is a mass or a volume.
On «The mole», use the slide model and vocabulary (mole, Avogadro's number, molar mass, coefficient) to replace this idea.

Try it yourself

Teach «The mole» aloud in 60 seconds using two bullets and one vocabulary word from mole.

Slide 4 · Concept

Molar mass

Molar mass from periodic table — g/mol.
One mole of CO2 has mass 44.01 g (use classroom significant figure conventions).

Core explanation

Molar mass: Molar mass from periodic table — g/mol. One mole of CO2 has mass 44.01 g (use classroom significant figure conventions). In class your teacher will expand on this; use these notes to recall the main science ideas.

Check your understanding

In your notebook, restate the main idea in one sentence without looking.
Name one new vocabulary word and define it in your own words.

Explain moreDeeper teaching notes — read like a tutor explaining the idea

Unit A — Molar mass: Molar mass from periodic table — g/mol. One mole of CO2 has mass 44.01 g (use classroom significant figure conventions). In Alberta Science 10, concepts at this level are about models and evidence, not memorizing trivia. Watch for this common confusion: Mole is a mass or a volume.. Link what you see on the slide to one outcome code from today's learning intentions.

Worked example(s)Step-by-step reasoning, not just answers

Apply: Molar mass
1. Identify the key idea: Molar mass from periodic table — g/mol.
2. Connect to a second point: One mole of CO2 has mass 44.01 g (use classroom significant figure conventions).
3. Give one new example (different from the slide) that fits both ideas.
Why this works: Application proves you understand the concept beyond repeating the slide.

Common mistakes to avoid

Mole is a mass or a volume.
Use the evidence and vocabulary on this slide ('Molar mass') to replace the incorrect idea with the class model.

Try it yourself

Explain 'Molar mass' to an imaginary classmate using at least two bullet ideas from the slide.

Slide 5 · Worked example

From equation to mole ratios

2 H2 + O2 → 2 H2O means 2 mol H2 reacts with 1 mol O2 producing 2 mol H2O.
Coefficients are mole ratios.

Core explanation

From equation to mole ratios: 2 H2 + O2 → 2 H2O means 2 mol H2 reacts with 1 mol O2 producing 2 mol H2O. Coefficients are mole ratios. In class your teacher will expand on this; use these notes to recall the main science ideas.

Check your understanding

In your notebook, restate the main idea in one sentence without looking.
Name one new vocabulary word and define it in your own words.

Explain moreDeeper teaching notes — read like a tutor explaining the idea

The mole links the invisible particle scale to measurable mass. One mole is 6.02 × 10²³ particles—Avogadro's constant. Mole ratios from balanced equations let you predict how much product forms from a given reactant.

Worked example(s)Step-by-step reasoning, not just answers

From equation to mole ratios
1. Step 1: 2 H2 + O2 → 2 H2O means 2 mol H2 reacts with 1 mol O2 producing 2 mol H2O.
2. Step 2: Coefficients are mole ratios.
3. Step: Check units and whether the answer fits the science context.
Why this works: Show your method; marks come from reasoning aligned to the Program of Studies.

Common mistakes to avoid

Mole is a mass or a volume.
On «From equation to mole ratios», use the slide model and vocabulary (mole, Avogadro's number, molar mass, coefficient) to replace this idea.
Jumping to the final number without showing steps.
Write each step in words; justify with energy, matter, or cell rules from the lesson.

Try it yourself

Repeat the method from «From equation to mole ratios» with different values or a new scenario from mole and conservation.

Slide 6 · Concept

Conservation revisited

Atom accounting in balanced equations supports conservation of mass.
Same moles of atoms each side for each element.

Core explanation

Conservation revisited: Atom accounting in balanced equations supports conservation of mass. Same moles of atoms each side for each element. In class your teacher will expand on this; use these notes to recall the main science ideas.

Check your understanding

In your notebook, restate the main idea in one sentence without looking.
Name one new vocabulary word and define it in your own words.

Explain moreDeeper teaching notes — read like a tutor explaining the idea

Unit A — Conservation revisited: Atom accounting in balanced equations supports conservation of mass. Same moles of atoms each side for each element. In Alberta Science 10, concepts at this level are about models and evidence, not memorizing trivia. Watch for this common confusion: Mole is a mass or a volume.. Link what you see on the slide to one outcome code from today's learning intentions.

Worked example(s)Step-by-step reasoning, not just answers

Apply: Conservation revisited
1. Identify the key idea: Atom accounting in balanced equations supports conservation of mass.
2. Connect to a second point: Same moles of atoms each side for each element.
3. Give one new example (different from the slide) that fits both ideas.
Why this works: Application proves you understand the concept beyond repeating the slide.

Common mistakes to avoid

Mole is a mass or a volume.
Use the evidence and vocabulary on this slide ('Conservation revisited') to replace the incorrect idea with the class model.

Try it yourself

Explain 'Conservation revisited' to an imaginary classmate using at least two bullet ideas from the slide.

Slide 7 · Guided practice

Calculations

How many moles of O2 needed to react with 4 mol H2?
Particles in 0.5 mol of NaCl formula units.

Core explanation

Calculations: How many moles of O2 needed to react with 4 mol H2? Particles in 0.5 mol of NaCl formula units. In class your teacher will expand on this; use these notes to recall the main science ideas.

Check your understanding

Try one practice item again without help—did your method change?

Explain moreDeeper teaching notes — read like a tutor explaining the idea

Guided practice is your bridge to doing problems alone. How many moles of O2 needed to react with 4 mol H2? Particles in 0.5 mol of NaCl formula units. Try the steps without looking, then compare. Mark where your reasoning differed — that gap is what to fix before the test of understanding in class.

Worked example(s)Step-by-step reasoning, not just answers

Calculations
1. Step 1: How many moles of O2 needed to react with 4 mol H2?
2. Step 2: Particles in 0.5 mol of NaCl formula units.
Why this works: Each step should name the science rule you are applying, not only the arithmetic.

Common mistakes to avoid

Mole is a mass or a volume.
Use the evidence and vocabulary on this slide ('Calculations') to replace the incorrect idea with the class model.

Try it yourself

Do one practice item for 'Calculations' without looking at the slide, then check.

Slide 8 · Formative check

Exit: Unit A synthesis

One sentence: how structure → formulas → equations → moles tells the story of Unit A.

Core explanation

Exit: Unit A synthesis: One sentence: how structure → formulas → equations → moles tells the story of Unit A. In class your teacher will expand on this; use these notes to recall the main science ideas.

Check your understanding

Compare your answer with a partner and fix one thing you would improve.

Explain moreDeeper teaching notes — read like a tutor explaining the idea

This is a check-in moment, not a secret test. One sentence: how structure → formulas → equations → moles tells the story of Unit A. Use wrong answers as data: note what you thought and what the class model says instead.

Worked example(s)Step-by-step reasoning, not just answers

Think through: Exit: Unit A synthesis
1. Restate the main idea in your own words: One sentence: how structure → formulas → equations → moles tells the story of Unit A.
2. List one observation or fact that supports it.
3. State one question you still have.
Why this works: Science 10 rewards clear reasoning, not only recall.

Common mistakes to avoid

Mole is a mass or a volume.
Use the evidence and vocabulary on this slide ('Exit: Unit A synthesis') to replace the incorrect idea with the class model.

Try it yourself

Answer the formative check idea from 'Exit: Unit A synthesis' in two sentences.

Slide 9 · Exit / preview

Unit B preview

Energy flow in technological systems — see placeholder on site.

Core explanation

Wrap-up: Energy flow in technological systems — see placeholder on site. Review these points after class while the ideas are fresh.

Check your understanding

Can you connect this slide to something we learned earlier today?

Explain moreDeeper teaching notes — read like a tutor explaining the idea

Unit B preview — Energy flow in technological systems — see placeholder on site. Connect this slide to 'The Mole and Conservation of Mass' and to outcome A-GO3-SO8. If anything is unclear, write a specific question for your teacher — vague 'I don't get it' is harder to help.

Worked example(s)Step-by-step reasoning, not just answers

Think through: Unit B preview
1. Restate the main idea in your own words: Energy flow in technological systems — see placeholder on site.
2. List one observation or fact that supports it.
3. State one question you still have.
Why this works: Science 10 rewards clear reasoning, not only recall.

Common mistakes to avoid

Mole is a mass or a volume.
Use the evidence and vocabulary on this slide ('Unit B preview') to replace the incorrect idea with the class model.

Try it yourself

Explain 'Unit B preview' to an imaginary classmate using at least two bullet ideas from the slide.