Units / Unit A

Word Equations and Balancing (Conservation of Mass)

Word ↔ balanced equations; Lavoisier conservation (A-GO3-SO6, SO1).

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

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Outcome checklist

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

A-GO3-SO6
By the end of this lesson you should be able to: Translate word equations to balanced chemical equations and vice versa for chemical reactions that occur in living and nonliving systems
Self-check: Without looking at your notes, give one example or explanation that shows you meet A-GO3-SO6.
A-GO3-SO1
By the end of this lesson you should be able to: Provide examples of household, commercial and industrial processes that use chemical reactions to produce useful substances and energy (e.g., baking powder in baking, combustion of fuels, electrolysis of water into H2(g) and O2(g))
Self-check: Without looking at your notes, give one example or explanation that shows you meet A-GO3-SO1.
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 A — Mole concept: Balanced equations enable mole ratios.

Glossary

reactant: Key vocabulary for this lesson (reactant). 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.
product: Key vocabulary for this lesson (product). 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.
subscript: Key vocabulary for this lesson (subscript). 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.
conservation of mass: In a closed system, total mass before and after a change stays the same (Lavoisier).

Lab and demo watch-outs

Lab conservation demo
Follow school lab procedures and WHMIS labels for any chemicals shown.
Whenever chemicals or equipment are used in class.

Lesson walk-through

Slide 1 · Hook

Lavoisier and the balance

Closed system mass before = mass after (within measurement).
Law of conservation of mass.

Core explanation

We start with a real situation: Closed system mass before = mass after (within measurement). Law of conservation of mass. 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 — Word Equations and Balancing (Conservation of Mass): Equations are sentences for reactions — balancing conserves atoms of each element. On this slide («Lavoisier and the balance»), the science story is: Closed system mass before = mass after (within measurement). Law of conservation of mass. 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-SO6, A-GO3-SO1.

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

Apply: Lavoisier and the balance
1. State the core idea: Closed system mass before = mass after (within measurement).
2. Link to a second point: Law of conservation of mass.
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

Change subscripts to balance.
On «Lavoisier and the balance», use the slide model and vocabulary (reactant, product, coefficient, subscript) to replace this idea.

Try it yourself

Teach «Lavoisier and the balance» aloud in 60 seconds using two bullets and one vocabulary word from reactant.

Slide 2 · Learning intent

Outcomes

A-GO3-SO6 translate word ↔ balanced equations.
A-GO3-SO1 useful processes: baking, fuels, electrolysis.

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-SO6 translate word ↔ balanced equations. A-GO3-SO1 useful processes: baking, fuels, electrolysis. Connect this slide to 'Word Equations and Balancing (Conservation of Mass)' and to outcome A-GO3-SO6. 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-SO6 translate word ↔ balanced equations.
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

Change subscripts to balance.
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

Word equations

Reactants → products with state symbols (s), (l), (g), (aq).
Example: methane combustion word form.

Core explanation

Word equations: Reactants → products with state symbols (s), (l), (g), (aq). Example: methane combustion word form. 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 — Word equations: Reactants → products with state symbols (s), (l), (g), (aq). Example: methane combustion word form. In Alberta Science 10, concepts at this level are about models and evidence, not memorizing trivia. Watch for this common confusion: Change subscripts to balance.. 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: Word equations
1. Identify the key idea: Reactants → products with state symbols (s), (l), (g), (aq).
2. Connect to a second point: Example: methane combustion word form.
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

Change subscripts to balance.
Use the evidence and vocabulary on this slide ('Word equations') to replace the incorrect idea with the class model.

Try it yourself

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

Slide 4 · Concept

Skeleton → balanced

Write correct formulas first.
Balance with coefficients — never change subscripts.

Core explanation

Skeleton → balanced: Write correct formulas first. Balance with coefficients — never change subscripts. 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 — Word Equations and Balancing (Conservation of Mass): Equations are sentences for reactions — balancing conserves atoms of each element. On this slide («Skeleton → balanced»), the science story is: Write correct formulas first. Balance with coefficients — never change subscripts. 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-SO6, A-GO3-SO1.

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

Apply: Skeleton → balanced
1. State the core idea: Write correct formulas first.
2. Link to a second point: Balance with coefficients — never change subscripts.
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

Change subscripts to balance.
On «Skeleton → balanced», use the slide model and vocabulary (reactant, product, coefficient, subscript) to replace this idea.

Try it yourself

Teach «Skeleton → balanced» aloud in 60 seconds using two bullets and one vocabulary word from reactant.

Slide 5 · Worked example

Combustion of propane

C3H8 + O2 → CO2 + H2O
Balance C, then H, then O.

Core explanation

Combustion of propane: C3H8 + O2 → CO2 + H2O Balance C, then H, then O. 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

Balancing equations counts atoms of each element on both sides—coefficients change amounts, subscripts do not. Each balanced equation is a statement of conservation of mass at the particle level. Practice saying what each coefficient means in words (moles of particles).

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

Combustion of propane
1. Step 1: C3H8 + O2 → CO2 + H2O
2. Step 2: Balance C, then H, then O.
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

Change subscripts to balance.
On «Combustion of propane», use the slide model and vocabulary (reactant, product, coefficient, subscript) 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 «Combustion of propane» with different values or a new scenario from word and balanced equations.

Slide 6 · Guided practice

Practice set

Synthesis: Mg + O2
Single replacement: Zn + HCl
Double replacement: NaCl + AgNO3 (predict precipitate).

Core explanation

Practice set: Synthesis: Mg + O2 Single replacement: Zn + HCl Double replacement: NaCl + AgNO3 (predict precipitate). 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. Synthesis: Mg + O2 Single replacement: Zn + HCl Double replacement: NaCl + AgNO3 (predict precipitate). 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

Practice set
1. Step 1: Synthesis: Mg + O2
2. Step 2: Single replacement: Zn + HCl
3. Step 3: Double replacement: NaCl + AgNO3 (predict precipitate).
Why this works: Each step should name the science rule you are applying, not only the arithmetic.

Common mistakes to avoid

Change subscripts to balance.
Use the evidence and vocabulary on this slide ('Practice set') to replace the incorrect idea with the class model.

Try it yourself

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

Slide 7 · Safety

Lab conservation demo

Closed flask on balance; discuss open system losses.

Core explanation

Lab conservation demo: Closed flask on balance; discuss open system losses. In class your teacher will expand on this; use these notes to recall the main science ideas.

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

Safety content is part of the Program of Studies, not optional extras. Closed flask on balance; discuss open system losses. At home, never substitute internet instructions for WHMIS labels, SDS sheets, or your teacher's directions.

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

Think through: Lab conservation demo
1. Restate the main idea in your own words: Closed flask on balance; discuss open system losses.
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

Change subscripts to balance.
Use the evidence and vocabulary on this slide ('Lab conservation demo') to replace the incorrect idea with the class model.

Try it yourself

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

Slide 8 · Exit / preview

Predict products

Next: predict products then balance.

Core explanation

Wrap-up: Next: predict products then balance. Review these points after class while the ideas are fresh. Copy the three most important ideas into a summary box. Tomorrow's class will build on at least one of them.

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

Predict products — Next: predict products then balance. Connect this slide to 'Word Equations and Balancing (Conservation of Mass)' and to outcome A-GO3-SO6. 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: Predict products
1. Restate the main idea in your own words: Next: predict products then balance.
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

Change subscripts to balance.
Use the evidence and vocabulary on this slide ('Predict products') to replace the incorrect idea with the class model.

Try it yourself

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

Slide 9 · STS connection

Industrial equations

Electrolysis of water: 2 H2O(l) → 2 H2(g) + O2(g) — energy and industry links.

Core explanation

Industrial equations: Electrolysis of water: 2 H2O(l) → 2 H2(g) + O2(g) — energy and industry links. In class your teacher will expand on this; use these notes to recall the main science ideas.

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

Science, Technology, and Society (STS): Electrolysis of water: 2 H2O(l) → 2 H2(g) + O2(g) — energy and industry links. Alberta expects you to connect science to people and decisions — name who benefits, who bears risk, and what evidence would change your view.

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

Think through: Industrial equations
1. Restate the main idea in your own words: Electrolysis of water: 2 H2O(l) → 2 H2(g) + O2(g) — energy and industry links.
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

Change subscripts to balance.
Use the evidence and vocabulary on this slide ('Industrial equations') to replace the incorrect idea with the class model.

Try it yourself

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