Topic 7 — Atoms, elements, molecules and compounds — blueprint for James

What I need from you: 4 decisions

1

Introduce "atom" as the name for the particles the course has drawn since Topic 1?

Topics 1 to 6 call every piece a particle. MAT-042 coins atom: the smallest particle of an element. From here the course draws atoms as circles with a size and a shade per element, and molecules as atoms joined.

the clean bridge is one sentence: "The particles we have drawn are made of even smaller pieces called atoms; in some substances the particle is one atom, in others it is a few atoms joined."

My recommendation: yes, that one-sentence bridge in L01, then the new drawings. Agree / change.

2

Draw atoms on a fixed glyph palette, naming real elements only where a substance is taught?

the register's behaviours are about reading and sorting particle diagrams. Two or three glyph kinds (a large open circle, a small dark circle, a shaded circle) are enough to draw elements, compounds and mixtures.

real names (oxygen, hydrogen, water, carbon dioxide) appear only where the lesson names a substance, with its glyph pattern shown once.

My recommendation: fixed glyphs; names only where a substance is taught. Agree / other.

3

Keep the capstone tree lesson (L07) as one lesson, walking the full tree on four cases?

MAT-047 classifies any sample to element / compound / homogeneous mixture / heterogeneous mixture. It joins Topic 5's tree to this topic's element-or-compound test.

My recommendation: one lesson, the tree drawn once, four cases walked, then a fluency quiz. Agree / split.

4

Which lessons could do without a video?

the sorts and the tree are page jobs; "why a compound differs from its elements" (L08) has the one dramatic contrast (two gases making a liquid) that a video shows well.

My recommendation: mark L03, L05, L06 and L07 "could do without a video"; all eight scripted. Agree / change.

Topic 7 at a glance — 8 lessons

LessonOpens onFormat
L01What an atom isCut a strip of aluminum foil in half.video + article
L02The smallest piece that is still the elementA copper wire is made of copper atoms.article only
L03One kind of atom: an elementHere are three particle drawings of three materials.article only
L04Atoms joined together: a moleculeIn one drawing the atoms float singly, each on its own.video + article
L05Different atoms joined in a fixed pattern: a compoundWater is made of two kinds of atom.article only
L06Element, compound or mixture from a drawingFour particle drawings, no labels.article only
L07Sort any sample: the full treeFour labeled cups: pure gold, distilled water, salt water, and sand in water.article only
L08A compound is not like its elementsHydrogen is a gas that burns.video + article
What this topic is, in five lines

Eight lessons, one per atom: MAT-042, 042b, 043, 044, 045, 046, 047, 048.

Terms coined here: atom (L01), element (L03), molecule (L04), compound (L05).

Deliberately not taught: protons and electrons (Topic 8), chemical symbols and formulas (Topics 9, 10), chemical reactions (Topic 12).

What an atom is L01

Cut a strip of aluminum foil in half.

Cut one half in half again, and again, and again.

The pieces get smaller each time.

Could you keep cutting forever?

The point, stated first

Is there a smallest piece of a material?

There is.

The particles this course has drawn are made of even smaller pieces.

The smallest piece of aluminum that is still aluminum is called an atom.

Every material is made of atoms.

Video: the strip halving down to one atom — video and article.

Part 1 — MAT-042 — State what an atom is; coin atom

Check: what (true / false ×3) → misconception item: a student says you could keep cutting forever — the key corrects: you reach a single atom → term recall

Figure: SVG: the strip halving in five steps, ending on one drawn atom

Leans on: T1 L02 (particles) — one recall question; MAT5-084 retrieved

Part 1q — Fluency quiz: atom

Check: fluency

Figure: —

Leans on: —

The smallest piece that is still the element L02

A copper wire is made of copper atoms.

Break off one copper atom.

Is that atom still copper?

Now split that atom into its parts.

Are the parts still copper?

The point, stated first

What is the smallest piece of an element that still counts as that element?

One atom of copper is still copper.

Anything smaller than one atom is no longer copper.

So the smallest piece of an element is a single atom.

Video: nothing a page cannot show — article only (a two-step drawing).

Part 1 — MAT-042b — Identify the smallest particle of a given element that still counts as that element

Check: fluency quiz: is this still the element? (one atom / half an atom / a hundred atoms), 6 quick cases across three named elements; misconception item: a student says half an atom of gold is still gold — the key corrects

Figure: SVG: a copper wire, one copper atom, and "smaller than an atom" crossed out

Leans on: L01 (atom) — one recall question

One kind of atom: an element L03

Here are three particle drawings of three materials.

In the first every atom is the same size and shade.

The second drawing shows one kind of atom as well.

In the third there are two kinds of atom.

Which of the three are made of only one kind of atom?

The point, stated first

What do you call a substance made of only one kind of atom?

Look at the atoms: are they all the same kind?

A substance made of only one kind of atom is called an element.

The first two drawings show elements.

The third does not.

Video: nothing a page cannot show — article only (the drawings are the lesson).

Part 1 — MAT-043 — Identify which substances are elements based on whether they contain only one kind of atom; coin element

Check: example sequence on particle drawings: element (all one glyph) → element (one glyph, atoms in pairs) → not an element (two glyphs) → element → not an element → rule; fluency quiz: element or not, 8 drawings

Figure: SVG: five particle boxes on the fixed glyph palette; the "one kind of atom?" question written under each

Leans on: L02 (atom) — one recall question

Part 1q — Fluency quiz: element

Check: fluency

Figure: —

Leans on: —

Atoms joined together: a molecule L04

In one drawing the atoms float singly, each on its own.

In another, atoms sit in pairs, touching, and the pairs move together.

Both drawings show the same kind of atom.

What is different about the second?

The point, stated first

What is a group of atoms that travel together?

In the second drawing each pair of atoms is joined.

A group of two or more atoms joined together is called a molecule.

The joined atoms move as one particle.

Single atoms, unjoined, are not molecules.

Video: pairs moving as one, singles moving alone — video and article.

Part 1 — MAT-044 — Identify which particle diagrams show molecules based on whether atoms are bonded together; coin molecule

Check: example sequence: molecule (a pair, same kind) → molecule (three atoms, two kinds) → not (single atoms) → molecule (a pair, two kinds) → not → rule; fluency quiz: molecule or not, 8 drawings

Figure: SVG: the drawings, joined atoms drawn touching, unjoined atoms apart

Leans on: L01 (atom) — one recall question

Part 1q — Fluency quiz: molecule

Check: fluency

Figure: —

Leans on: —

Different atoms joined in a fixed pattern: a compound L05

Water is made of two kinds of atom.

Every water particle has the same pattern: one large atom joined to two small ones.

Pick any water particle anywhere in the world and the pattern is the same.

Is water an element?

The point, stated first

What do you call a substance whose particles are two or more kinds of atom joined in a fixed pattern?

Water is not an element, because it has two kinds of atom.

Its atoms are joined, in the same pattern every time.

A substance made of two or more different kinds of atom joined together in a fixed pattern is called a compound.

Water is a compound.

Video: nothing a page cannot show — article only.

Part 1 — MAT-045 — Identify which substances are compounds based on whether two or more different elements are chemically combined in a fixed ratio; coin compound

Check: example sequence on drawings: compound (two kinds joined, same pattern) → compound (three kinds joined) → not (one kind joined: an element) → not (two kinds, unjoined: a mixture, named as "not a compound" here) → rule; fluency quiz: compound or not, 8 drawings; misconception item: a student says any drawing with two kinds of atom is a compound — the key corrects: joined, in a fixed pattern

Figure: SVG: the drawings; the water pattern drawn once and repeated

Leans on: L03 (element) and L04 (molecule) — one recall question each

Part 1q — Fluency quiz: compound

Check: fluency

Figure: —

Leans on: —

Element, compound or mixture from a drawing L06

Four particle drawings, no labels.

Some show one kind of atom, some two.

In some the atoms are joined, in some they float apart.

Sort the four with one question at a time.

The point, stated first

How do you sort a particle drawing?

First ask how many kinds of atom the drawing shows.

One kind of atom makes an element.

If there is more than one kind, ask whether the different kinds are joined in a fixed pattern.

Joined kinds make a compound.

Unjoined kinds, just mingled, make a mixture.

Video: nothing a page cannot show — article only.

Part 1 — MAT-046 — Sort particle diagrams into elements, compounds and mixtures using the one-kind-of-atom test

Check: scaffolded (type b): worked walk of the two questions on one drawing → step items on a fresh drawing → fluency quiz: element / compound / mixture, 8 drawings

Figure: SVG: the two-question tree with a drawing at each leaf; the four drawings

Leans on: L03, L04, L05 — one recall question each; T5 L02 (mixture)

Sort any sample: the full tree L07

Four labeled cups: pure gold, distilled water, salt water, and sand in water.

Topic 5 sorted samples into pure substance or mixture.

This topic sorted pure substances into element or compound.

Put the two sorts together into one tree.

The point, stated first

How do you place any sample in one of four categories?

First ask whether the sample holds one kind of matter.

A sample with more than one kind is a mixture; then ask whether it is the same all the way through, which splits homogeneous from heterogeneous.

A sample with one kind of matter is a pure substance; then ask whether it has one kind of atom, which splits element from compound.

Gold comes out as an element, distilled water as a compound, salt water as a homogeneous mixture, and sand in water as a heterogeneous mixture.

Video: nothing a page cannot show — article only.

Part 1 — MAT-047 — Classify any sample to the leaf level (element, compound, homogeneous mixture or heterogeneous mixture) by working through the decision tree

Check: scaffolded (type b): worked walk on one case → step items on a fresh case → fluency quiz: four categories, 8 fresh described samples

Figure: SVG: the full tree, four leaves, a particle box at each leaf

Leans on: T5 L05 (the pure/mixture tree) and L06 — one recall question each

A compound is not like its elements L08

Hydrogen is a gas that burns.

Oxygen is a gas that helps things burn.

Join them in a fixed pattern and you get water.

Water is a liquid, and it puts fires out.

How can two gases make a liquid that does the opposite?

The point, stated first

Why does a compound behave nothing like the elements in it?

In water, the hydrogen and oxygen atoms are joined into water particles.

A water particle is a new kind of particle, not a hydrogen atom sitting next to an oxygen atom.

New particles behave in new ways.

So a compound's properties belong to its own particles, not to the elements it was made from.

Video: two gases, then the joined particle, then the liquid — video and article.

Part 1 — MAT-048 — Explain why a compound can have completely different properties from the elements it is made of

Check: what (table salt from a soft metal and a green gas: does salt behave like either) → why (free response) → misconception item: a student says water must burn because hydrogen burns — the key corrects: the water particle is a new particle → transfer (a compound of carbon and oxygen, a gas, is not black like carbon)

Figure: table: hydrogen, oxygen, water — one property each; SVG: two gas boxes and the water box with joined particles

Leans on: L05 (compound) — one recall question

Topic close

Mixed mastery practice: 12 items; the four coined terms by typed recall; two full tree sorts as free response; drawings to sort.

Then the PP100: a bank of at least 50 four-option MCQs on fresh instances and fresh drawings, tagged easy / medium / hard by depth of reasoning, at least three per atom.

The course architecture (14 topics) — open only if you want the whole map

Skill: course-build → atomise (architecture, step 6b gate) → write-like-james @ 4c9e849

MS Chemistry — course architecture v1 (for James's approval, 25 September 2026)

Read this in five minutes. It decides the topics, their order, where every PP100 sits, and which topic pilots first. Nothing below writes a lesson sentence. The atom register stays where it is: the Matter strand of the Science Knowledge Graph (92 atoms, JM-reviewed). This document arranges those 92 atoms into a course and stops.

The takeaways

Status (25 September, later the same day): you approved Topic 1 as the pilot and clarified delivery (video or article per atom, then questions). Card 5 records that. The ask now: approve or edit the Topic 1 blueprint (course_preview/review/BLUEPRINT_T01.html); lesson writing starts on your word.


Card 1 — The topics

The call: fourteen topics in the order below, a mixed mastery practice set then a PP100 at the end of every one.

#Topic (student-facing title)AtomsLessonsTEKS stampThe big idea it serves
1Particles and the three states of matterMAT-001, 002, 003, 004, 016, 016b, 017, 017b, 018, 018b, 019, 019b126.6AEverything is made of moving particles; that explains solids, liquids and gases
2Changing stateMAT-020, 021, 022, 023, 024, 025, 026, 026b86.6A (NGSS MS-PS1-4)Heating and cooling change how particles move, not what they are; mass holds
3Physical propertiesMAT-005, 006, 007, 012, 01356.6DProperties you can measure without changing the substance
4DensityMAT-008, 009, 010, 011, 01556.6DA property that identifies a substance whatever the sample size
5Pure substances and mixturesMAT-027, 028, 029, 030, 03256.6BSorting matter by how many kinds it contains
6Solutions and separating mixturesMAT-033, 034, 035, 036, 037, 038, 039, 040, 04197.6D, 7.6E, pre-6.6BA mixture keeps its parts' properties, so you can pull it apart
7Atoms, elements, molecules and compoundsMAT-042, 042b, 043, 044, 045, 046, 047, 04887.6AOne kind of atom or more than one: the particle-level sort
8Inside the atomMAT-049, 050, 051, 051b, 0525(NGSS MS-PS1-1; FL SC.8.P.8.7)Protons decide which element an atom is
9The periodic tableMAT-053, 054, 054b, 055, 056, 057, 05876.6CThe table arranges elements so position predicts properties
10Chemical formulasMAT-059, 059b, 060, 06147.6BA formula counts atoms; change the count and you change the substance
11Physical and chemical changeMAT-062, 063, 064, 064b, 065, 065b67.6CDid a new substance form? The one test, and its evidence
12Chemical reactions and conservation of massMAT-066, 067, 068, 069, 069b, 070, 071, 07288.6E, 8.6BReactions rearrange atoms; none appear or vanish, so mass holds
13Water's special propertiesMAT-073, 074, 075, 07648.6CWater particles pull on each other and on other surfaces
14Acids and basesMAT-077, 078, 079, 080, 081, 08268.6DTwo families of substance, one scale, and what happens when they meet

Totals: 92 lessons, 14 practice sets, 14 PP100s (280 items), 3 checkpoint tests. Two atoms may need a second lesson once blueprinted — MAT-010 (calculate density) and MAT-061 (coefficients and parentheses) — so plan for 92 to 94.

Why this grouping

What changes: the course folder gets one topicNN_build/ folder per topic; Topic 1's blueprint is written; nothing else is authored until you approve it.


Card 2 — Topic 1 is the pilot, at 12 lessons

The call: pilot "Particles and the three states of matter" end to end — 12 lessons, quiz after each, mixed practice, PP100 — before any other topic starts.

Why

The alternative is a 10/10 cut: move the two kinetic-energy atoms (MAT-019, 019b) to the front of Topic 2, where kinetic energy is the lever for melting. I kept them in Topic 1 because TEKS 6.6A names kinetic energy in the states comparison, and the ranking closes the three-box picture.

What changes: the Topic 1 blueprint is the next thing you read.


Card 3 — Density stands alone

The call: Topic 4 "Density" (5 atoms) is separate from Topic 3 "Physical properties" (5 atoms).

Why

What changes: two PP100s where the register had one sub-domain.


Card 4 — Checkpoints at three seams

The call: three static checkpoint tests, each with some free response, at the ends of Topics 6, 10 and 14; the third doubles as the end-of-course test and is anchored to released grade-8 STAAR, Florida SSA and AZSCI items.

Why

What changes: nothing yet. Checkpoints are built after the topics they cover.


Card 5 — Delivery: video or article per atom, quiz straight after

The call: every lesson (one per atom) ships as BOTH a 40–90 second video and a short article, and the student chooses which to take; the quiz follows in the app, never inside the video. At topic end: mixed mastery practice (any format, key terms by recall), then the PP100 (20 MCQs, easy/medium/hard). No topic intro or summary videos.

Why

Skills that run per lesson, in order: write-lesson (dispatching by lesson type) for the article → write-video-script for the video → design-check-sequence then write-mcqs for the quiz → review-accuracy (a reader who did not write it, against the reference) → review-figures on every rendered figure → review-lesson (blind key read, guidance read, adjudication) → blind review of every key before anything ships.

Figures: the blueprint names the figure kind per part. Particle pictures are always monochrome SVG drawings, one depiction reused everywhere. Real scenes a student should recognise (a tea bag colouring water, sand pouring into a jar) are licensed stock photos where the photo carries the point; a drawing where the point is a measurement or a label.

What changes: the blueprint carries a delivery line and an SVG-or-photo call on every figure.


Card 6 — Five prerequisites are taught in other strands

The call: the five cross-strand prerequisites below are not taught in MS Chemistry. Each lesson that leans on one states the fact in one sentence and asks one recall question before using it.

External atomWhat it saysLeaned on by
ENE-020Temperature measures average particle motionMAT-004 (Topic 1)
ENE-021Heat flows from hot to coldMAT-020–023 (Topic 2)
ENE-025Thermal conductors and insulatorsMAT-013 (Topic 3)
FOR-017Spot a magnetic forceMAT-041 (Topic 6)
LIF-073The photosynthesis word equationMAT-072 (Topic 12)

Why

What changes: the blueprint's "leans on" column names the external atom wherever it applies.


Card 7 — Register observations, no edits made

The call: seven observations for your atomisation pass. I changed nothing in the register.

  1. MAT-013 sorts materials as thermal and electrical conductors — two property families in one behaviour (the "and" audit). Candidate split.
  2. MAT-022 "Evaporation and boiling" — evaporation happens at the surface below the boiling point; boiling happens throughout at one temperature. Two predictions, one atom. Candidate split.
  3. MAT-050 states the charge and location of three particles — six facts in one contrast frame. HS Chemistry kept a similar profile atom whole as an argued exception; flagging for the same argument here.
  4. MAT-061 counts atoms with "a coefficient, parentheses, or both" — two routines, likely two lessons.
  5. MAT-019b may not fail independently of MAT-019 in practice. Kept as its own lesson; the data decides (guide: never pre-emptively merge).
  6. MAT-004 → MAT-016/017/018. Identifying a solid from its behaviour does not need "heating speeds particles". The edge is honoured in the order, but it looks like a sequencing edge rather than a knowledge one.
  7. MAT-042 has no in-strand prerequisite and enters via MAT5-084 only; Topic 7 must open with the particle picture from Topic 1 as its retrieval.

What changes: nothing until you rule. Atom edits happen in the knowledge-graph repo with a log entry.


About this build (kickoff record)

What happens next

You approve or edit the topic table. Then you read the Topic 1 blueprint. Only after that does write-lesson run on Topic 1, one lesson at a time, starting with the first of each lesson type as its exemplar.