Topic 7 — Atoms, elements, molecules and compounds — blueprint for James
What I need from you: 4 decisions
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.
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.
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.
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
| Lesson | Opens on | Format | |
|---|---|---|---|
| L01 | What an atom is | Cut a strip of aluminum foil in half. | video + article |
| L02 | The smallest piece that is still the element | A copper wire is made of copper atoms. | article only |
| L03 | One kind of atom: an element | Here are three particle drawings of three materials. | article only |
| L04 | Atoms joined together: a molecule | In one drawing the atoms float singly, each on its own. | video + article |
| L05 | Different atoms joined in a fixed pattern: a compound | Water is made of two kinds of atom. | article only |
| L06 | Element, compound or mixture from a drawing | Four particle drawings, no labels. | article only |
| L07 | Sort any sample: the full tree | Four labeled cups: pure gold, distilled water, salt water, and sand in water. | article only |
| L08 | A compound is not like its elements | Hydrogen 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?
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
Part 1q — Fluency quiz: atom
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?
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
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?
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
Part 1q — Fluency quiz: element
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?
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
Part 1q — Fluency quiz: molecule
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?
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
Part 1q — Fluency quiz: compound
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.
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
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.
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
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?
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
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
- Fourteen topics, one PP100 at the end of each, 92 lessons in all. One atom, one lesson. Topics run 4 to 12 atoms; the average is 6 or 7.
- The order follows the big ideas, not the TEKS list: what matter is and how particles explain it → what properties tell you → sorting matter into kinds → inside the atom and the periodic table → how matter changes → two grade-8 applications (water, acids and bases).
- Topic 1 is the pilot: "Particles and the three states of matter", 12 lessons. It stresses every treatment the course will need — a two-part test taught by examples, a fact, two "explain the smell" mechanisms, three example-sequence classifications, three particle-picture why-lessons, one coined term with a ranking routine. Its blueprint is the second deliverable.
- Density is its own topic. It carries the course's first two calculation routines, so it gets its own practice set and PP100 (vault ruling: a quantitative subtopic becomes its own topic).
- Three checkpoint tests, at the three natural seams, anchored to the released grade-8 STAAR, Florida SSA and AZSCI forms. Grade-level slices remain derivable from the TEKS stamps if operations later want them.
- Five prerequisites live in other strands and are not taught here. Each lesson that leans on one states it in a sentence and asks one recall question. Nothing is assumed (stand-alone entry rule).
- Seven register observations for your atomisation pass. No atom was edited; the register is read-mostly.
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) | Atoms | Lessons | TEKS stamp | The big idea it serves |
|---|---|---|---|---|---|
| 1 | Particles and the three states of matter | MAT-001, 002, 003, 004, 016, 016b, 017, 017b, 018, 018b, 019, 019b | 12 | 6.6A | Everything is made of moving particles; that explains solids, liquids and gases |
| 2 | Changing state | MAT-020, 021, 022, 023, 024, 025, 026, 026b | 8 | 6.6A (NGSS MS-PS1-4) | Heating and cooling change how particles move, not what they are; mass holds |
| 3 | Physical properties | MAT-005, 006, 007, 012, 013 | 5 | 6.6D | Properties you can measure without changing the substance |
| 4 | Density | MAT-008, 009, 010, 011, 015 | 5 | 6.6D | A property that identifies a substance whatever the sample size |
| 5 | Pure substances and mixtures | MAT-027, 028, 029, 030, 032 | 5 | 6.6B | Sorting matter by how many kinds it contains |
| 6 | Solutions and separating mixtures | MAT-033, 034, 035, 036, 037, 038, 039, 040, 041 | 9 | 7.6D, 7.6E, pre-6.6B | A mixture keeps its parts' properties, so you can pull it apart |
| 7 | Atoms, elements, molecules and compounds | MAT-042, 042b, 043, 044, 045, 046, 047, 048 | 8 | 7.6A | One kind of atom or more than one: the particle-level sort |
| 8 | Inside the atom | MAT-049, 050, 051, 051b, 052 | 5 | (NGSS MS-PS1-1; FL SC.8.P.8.7) | Protons decide which element an atom is |
| 9 | The periodic table | MAT-053, 054, 054b, 055, 056, 057, 058 | 7 | 6.6C | The table arranges elements so position predicts properties |
| 10 | Chemical formulas | MAT-059, 059b, 060, 061 | 4 | 7.6B | A formula counts atoms; change the count and you change the substance |
| 11 | Physical and chemical change | MAT-062, 063, 064, 064b, 065, 065b | 6 | 7.6C | Did a new substance form? The one test, and its evidence |
| 12 | Chemical reactions and conservation of mass | MAT-066, 067, 068, 069, 069b, 070, 071, 072 | 8 | 8.6E, 8.6B | Reactions rearrange atoms; none appear or vanish, so mass holds |
| 13 | Water's special properties | MAT-073, 074, 075, 076 | 4 | 8.6C | Water particles pull on each other and on other surfaces |
| 14 | Acids and bases | MAT-077, 078, 079, 080, 081, 082 | 6 | 8.6D | Two 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
- Every prerequisite edge in the register points backwards in this order. Checked atom by atom; no forward reference.
- Sub-domains 2 and 3 were each split in two (Topics 3/4 and 1/2). SD-3 has 16 atoms; a 20-item PP100 over 16 atoms certifies nothing. SD-2 bundles a calculation routine with observational properties.
- Topics 5 to 7 form one sort of matter in three passes: by how many substances (5), by whether it is a solution (6), by what the particles are (7). The full classification tree (MAT-047) closes Topic 7.
- Topics 13 and 14 sit last. Nothing depends on them, they are the register's only pure grade-8 applications, and the checkpoint before them then covers a clean block.
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 vertical-slice rule asks for a routine, a categorical concept and an explanation in the pilot. Topic 1 has all three: three example-sequence classifications (solid, liquid, gas), three why-lessons on the particle picture, a ranking routine that coins the course's first technical term, and a transformation (heating speeds particles).
- It is the course's foundation. Every later topic reuses its one particle picture and its four sentences about arrangement and movement.
- SD-1 alone (4 atoms) would pilot fast but would not test a PP100 worth the name, and has no routine.
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
- Density carries two routines (displacement volume, MAT-008; calculate density, MAT-010) plus the sink-or-float prediction and the "same whatever the sample size" fact.
- Vault ruling (AP Biology, 10 Sep 2026): a topic test that mixes a calculation routine with a content topic hides which one failed.
- Solubility (MAT-012) and conductors (MAT-013) stay in Topic 3 as properties; Topic 6 retrieves solubility with a recall question.
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
- The seams are natural: Topics 1–6 are matter you can see and handle; 7–10 are the atom and its table; 11–14 are change and two applications.
- No state tests middle-school science before grade 8, so there is no per-grade instrument to anchor to (HANDOFF recommendation 1). The TEKS stamps (6.x/7.x/8.x on every atom) still allow a grade-level slice later without re-atomising.
- Five interchangeable forms per test is the standing ruling for topic tests; whether checkpoints also get five forms is your call.
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
- Your format ladder of 25 September, with your clarification the same day: each atom is a video with the option to read the article instead. The platform's learner's-choice mode carries exactly that.
- When video and text are alternatives, each must teach the whole part (vault rule), so the video script (write-video-script) and the article (write-lesson) are written from the same blueprint row and reviewed against each other.
- Pitched one notch up from the Grade 3 Forces pack: no title slide, open on the first example, rule stated last, everything appears on the word that names it. Middle school may carry a short "why" where Grade 3 stayed qualitative.
- The ladder names no intro or summary video. AP Biology and HS Chemistry ran different intro policies; I have not inherited either.
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 atom | What it says | Leaned on by |
|---|---|---|
| ENE-020 | Temperature measures average particle motion | MAT-004 (Topic 1) |
| ENE-021 | Heat flows from hot to cold | MAT-020–023 (Topic 2) |
| ENE-025 | Thermal conductors and insulators | MAT-013 (Topic 3) |
| FOR-017 | Spot a magnetic force | MAT-041 (Topic 6) |
| LIF-073 | The photosynthesis word equation | MAT-072 (Topic 12) |
Why
- Stand-alone entry rule: no student has taken the 3–5 courses or the sibling MS courses, so every lesson stands alone.
- One loop to know about: ENE-020 (Energy) lists MAT-002 and MAT-003 as its prerequisites, and MAT-004 lists ENE-020. Inside this course MAT-004 carries the "hotter means faster particles" idea itself; the Energy course will meet it as retrieval.
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.
- MAT-013 sorts materials as thermal and electrical conductors — two property families in one behaviour (the "and" audit). Candidate split.
- 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.
- 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.
- MAT-061 counts atoms with "a coefficient, parentheses, or both" — two routines, likely two lessons.
- MAT-019b may not fail independently of MAT-019 in practice. Kept as its own lesson; the data decides (guide: never pre-emptively merge).
- 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.
- 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)
- Register:
Science Knowledge Graph/data/atoms/06-08/matter.json, pulled 25 September 2026, 92 atoms in 13 sub-domains. Per-course choices are the register's: K-8 IDs with letter suffixes; Fact / Categorical / Transformation / Routine; bare behaviours; verdict/reason split by default. - Endpoint: grade-8 STAAR, Florida SSA and AZSCI physical-science items; NGSS MS-PS1-1/2/4/5.
- Sources read: knowledge-graph HANDOFF and CLAUDE; vault CLAUDE, 00 Protocol, the PP100 and build-process-v2 rulings, the blueprint rule; the Grade 3 Forces feedback log; the chemistry misconception research (particle model area). HS Chemistry Unit 1 was opened before this document was written; under your same-day correction it is reference only, and Topic 1's scenes were chosen fresh.
- Coverage check (standards mapped onto this architecture, never the other way): every Matter atom sits in exactly one topic; every TEKS 6.6/7.6/8.6 knowledge code in the register appears in at least one topic. Blank cells in the register (e.g. NGSS on solutions, TEKS on atomic structure) are register findings, not gaps in this course.
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.