Units / Unit A / The Mole and Conservation of Mass

The Mole and Conservation of Mass

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

Full lesson guide (printable)

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.

Slide 1 of 911%

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.