Units / Unit A / Particles of Matter: From Macro to Subatomic

Particles of Matter: From Macro to Subatomic

Introduce the particle model, pure substances vs mixtures, and how evidence supports subatomic structure (A-GO1).

Full lesson guide (printable)

Outcome checklist

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

A-GO1-SO1
By the end of this lesson you should be able to: Identify historical examples of how humans worked with chemical substances to meet their basic needs (e.g., how pre-contact First Nations communities used biotic and abiotic materials to meet their needs)
Self-check: Without looking at your notes, give one example or explanation that shows you meet A-GO1-SO1.
A-GO1-SO2
By the end of this lesson you should be able to: Outline the role of evidence in the development of the atomic model consisting of protons and neutrons (nucleons) and electrons; i.e., Dalton, Thomson, Rutherford, Bohr
Self-check: Without looking at your notes, give one example or explanation that shows you meet A-GO1-SO2.
A-GO1
Big idea: Describe the basic particles that make up the underlying structure of matter, and investigate related technologies
Self-check: How does today's lesson connect to A-GO1?

Where this shows up later

Unit A — Atomic models: Evidence for subatomic structure builds on the particle model.
Unit A — Bonding: Elements and compounds connect to how particles combine.

Glossary

particle model: The idea that all matter is made of tiny particles in motion with space between them.
pure substance: Matter with fixed composition (an element or a compound).
mixture: Two or more substances physically combined; composition can vary.
element: A pure substance made of one type of atom (one atomic number).
compound: A pure substance with two or more elements chemically bonded in fixed ratios.

Lab and demo watch-outs

Before lab or demo
Prepare demo materials: salt, water, iron filings, sulfur (do not heat yet).
Follow your teacher's instructions and school safety rules.

Slide 1 of 1010%

Hook

Why does sugar disappear in tea?

Observe: solid sugar becomes a sweet liquid — the glass still weighs more.
Question: Is the sugar still there? What changed?
Today: connect visible changes to the particle model of matter.

Core explanation

We start with a real situation: Observe: solid sugar becomes a sweet liquid — the glass still weighs more. Question: Is the sugar still there? What changed? Today: connect visible changes to the particle model of matter. 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

Dissolving sugar in tea is a powerful Grade 10 example of the particle model. The sweet taste and unchanged total mass are macro evidence that sugar particles are still present—they spread among water particles rather than vanishing. Dissolving is a physical change: no new chemical substance forms, which is different from burning sugar. In Alberta classrooms we use observations like this before introducing atomic structure; your POS outcome A-GO1-SO1 also connects human use of materials to meeting needs, which includes everyday mixtures like tea.

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

Evidence journal: sugar in tea
1. Observation: mass of cup + sugar + water before mixing equals mass after (if none spills).
2. Inference: particles of sugar are distributed in the liquid—you taste them everywhere.
3. Question: if particles spread, why can you still filter out sand but not dissolved sugar?
4. Contrast: dissolving (physical) vs burning (chemical—new substances).
Why this works: Link each observation to particles; avoid saying matter 'disappears'.

Common mistakes to avoid

Students may think atoms are like tiny solid balls with no internal structure.
On «Why does sugar disappear in tea?», use the slide model and vocabulary (particle model, pure substance, mixture, element) to replace this idea.
Students may confuse physical mixing with chemical bonding.
On «Why does sugar disappear in tea?», use the slide model and vocabulary (particle model, pure substance, mixture, element) to replace this idea.

Try it yourself

Describe dissolving salt in water using the particle model. Include one observation, one inference about particles, and state whether it is physical or chemical.