Topic 6 — Solutions and separating mixtures — blueprint for James
What I need from you: 4 decisions
Run the three "what speeds up dissolving" atoms as one lesson each, or one lesson with three parts?
MAT-038 (temperature), MAT-039 (surface area) and MAT-040 (stirring) each predict which of two otherwise identical set-ups dissolves faster. Same shape three times.
one atom, one lesson is the standing ruling; three short lessons keep each variable separately failable. A single lesson would carry three headaches.
My recommendation: three lessons (L06, L07, L08), each about 60 seconds of video, with the same two-cup scene varied one way each time. Three / one.
Coin concentration in plain words only, with no formula or number?
MAT-035 orders solutions by concentration from the amounts given; MAT-036 predicts dilution. Neither needs a formula, and grams per liter is not in the register.
My recommendation: plain words, no formula, compare by "more solute in the same water" or "same solute in more water". Agree / add g per 100 mL.
Separating a mixture (L09) leans on the magnet from the Forces strand. State it as one sentence?
MAT-041 lists FOR-017 (spot a magnetic force). No MS Chemistry lesson teaches magnets. Topic 5 L03 already used the magnet scene as a fact.
My recommendation: one sentence ("a magnet pulls iron; it does not pull sand"), no more. Agree / other.
Which lessons could do without a video?
dissolving, stirring, and the four separations all move. Labelling solute and solvent (L02) and ordering by concentration (L03) are page jobs.
My recommendation: mark L02 and L03 "could do without a video"; all nine scripted. Agree / change.
Topic 6 at a glance — 9 lessons
| Lesson | Opens on | Format | |
|---|---|---|---|
| L01 | What a solution is | A student stirs a spoon of sugar into a glass of water until it vanishes. | video + article |
| L02 | Solute and solvent | A label on a bottle reads: "salt water — 10 g of salt in 500 mL of water". | article only |
| L03 | How concentrated? | Three glasses each hold 200 mL of water. | article only |
| L04 | Adding water: dilution | A glass holds a strong, dark cordial: 40 g of syrup in 200 mL of water. | video + article |
| L05 | Mass adds up when a solution forms | A student weighs 200 g of water in a beaker. | video + article |
| L06 | Dissolving faster: warmer water | Two cups each hold 200 mL of water and one sugar cube. | video + article |
| L07 | Dissolving faster: smaller pieces | Two cups each hold 200 mL of water at 20 °C. | video + article |
| L08 | Dissolving faster: stirring | Two cups each hold 200 mL of water at 20 °C and one sugar cube. | video + article |
| L09 | Choose a way to separate a mixture | A student has three mixtures on the bench: sand in water, salt in water, and iron filings in sand. | video + article |
What this topic is, in five lines
Nine lessons, one per atom: MAT-033, 034, 035, 036, 037, 038, 039, 040, 041.
Terms coined here: solution (L01), solute and solvent (L02), concentration (L03), dilute (L04), and the four separation names filtering, evaporating, using a magnet, sieving (L09).
Deliberately not taught: solubility limits and saturation, concentration as a number, distillation and chromatography.
What a solution is L01
A student stirs a spoon of sugar into a glass of water until it vanishes.
She stirs a spoon of flour into a second glass.
The flour turns the water cloudy and slowly settles to the bottom.
Both are mixtures.
Why does only the sugar seem to disappear?
What kind of mixture does dissolving make?
The sugar breaks into particles too small to see and spreads evenly through the water.
A mixture in which one substance has dissolved evenly into another is called a solution.
The flour does not dissolve; its grains stay grains and settle.
Flour and water is a mixture, but not a solution.
Video: the sugar vanishing while the flour clouds and settles — video and article.
Part 1 — MAT-033 — Identify which mixtures are solutions based on whether one substance has dissolved evenly into another; coin solution
Part 1q — Fluency quiz: solution
Solute and solvent L02
A label on a bottle reads: "salt water — 10 g of salt in 500 mL of water".
Two substances made this solution.
One did the dissolving; one was dissolved.
Which is which, and does it matter which you call what?
What are the two parts of a solution called?
The substance that dissolves is called the solute: here, the salt.
The substance it dissolves into is called the solvent: here, the water.
The solvent is the one there is more of, and it is usually a liquid.
Solute into solvent makes a solution.
Video: nothing a page cannot show — article only.
Part 1 — MAT-034 — Label the solute and solvent in a given solution; coin solute, solvent
Part 1q — Fluency quiz: solute / solvent
How concentrated? L03
Three glasses each hold 200 mL of water.
A student stirs 1 spoon of drink powder into the first, 2 into the second, 4 into the third.
All three spoonfuls dissolve completely.
She tastes them: the third is by far the strongest.
What is different about the third glass?
What makes one solution stronger than another?
The third glass has more solute in the same amount of solvent.
How much solute is dissolved in each amount of solvent is called the concentration.
More solute in the same solvent: more concentrated.
Less solute in the same solvent: less concentrated.
Video: nothing a page cannot show — article only; the comparison is a table.
Part 1 — MAT-035 — Order solutions from most to least concentrated given the amounts of solute and solvent in each; coin concentration
Part 1q — Fluency quiz: concentration (the plain meaning)
Adding water: dilution L04
A glass holds a strong, dark cordial: 40 g of syrup in 200 mL of water.
A student tops it up to 400 mL with more water.
The color goes paler and the taste weaker.
No syrup was taken out.
Why is the drink weaker?
What happens to a solution when you add more solvent?
The same 40 g of syrup is now spread through 400 mL of water instead of 200 mL.
Each sip holds less syrup.
The concentration has gone down.
Adding solvent to a solution is called diluting it.
Video: the color paling as water is poured in, particles spreading out — video and article.
Part 1 — MAT-036 — Predict what happens to the concentration of a solution when more solvent is added; coin dilute
Part 1q — Fluency quiz: dilute
Mass adds up when a solution forms L05
A student weighs 200 g of water in a beaker.
She weighs 15 g of salt on a paper.
She tips the salt in and stirs until it vanishes.
She puts the beaker back on the balance.
What does it read?
What happens to the mass when a solute dissolves?
Every salt particle is still in the beaker, spread through the water.
No particle left and none arrived.
So the mass of the solution is the mass of the water plus the mass of the salt: 200 g + 15 g = 215 g.
Video: the balance reading climbing to 215 g as the salt goes in and vanishes — video and article.
Part 1 — MAT-037 — Calculate the total mass of a solution from the masses of solute and solvent before mixing
Dissolving faster: warmer water L06
Two cups each hold 200 mL of water and one sugar cube.
One cup is at 20 °C; the other at 60 °C.
Nobody stirs.
The cube in the hot cup is gone in 3 minutes; the cube in the cold cup takes 12.
Why does the hot water dissolve it faster?
Why does sugar dissolve faster in hot water?
Heating makes the water particles move faster.
Faster water particles hit the sugar cube harder and more often.
They knock sugar particles off the cube sooner.
So the warmer the solvent, the faster the solute dissolves.
Video: the two cubes shrinking at different rates — video and article.
Part 1 — MAT-038 — Predict which of two otherwise identical solutions dissolves faster when the temperature is higher
Dissolving faster: smaller pieces L07
Two cups each hold 200 mL of water at 20 °C.
One gets a sugar cube; the other gets the same mass of sugar as loose grains.
Nobody stirs.
The grains vanish long before the cube.
The sugar, the water and the temperature are the same in both cups.
Why do the grains win?
Why do small grains dissolve faster than one cube?
Water particles can only knock sugar particles off the surface.
The loose grains have far more surface for the water to reach.
So more sugar particles are knocked off at once.
The more surface a solute has, the faster it dissolves.
Video: the grains shrinking away while the cube barely changes — video and article.
Part 1 — MAT-039 — Predict which of two equal-mass solute samples dissolves faster based on their particle size
Dissolving faster: stirring L08
Two cups each hold 200 mL of water at 20 °C and one sugar cube.
A student stirs one cup and leaves the other still.
The stirred cube is gone in 2 minutes; the still one takes 12.
Why does stirring help?
Why does stirring speed up dissolving?
Around a still cube, the water nearby soon holds many sugar particles.
Stirring sweeps that water away and brings fresh water to the cube.
Fresh water knocks more sugar particles off.
So stirring makes a solute dissolve faster.
Video: the stirred cube shrinking, the sugar-rich water swept away — video and article.
Part 1 — MAT-040 — Predict which of two otherwise identical solutions dissolves faster when one is stirred
Choose a way to separate a mixture L09
A student has three mixtures on the bench: sand in water, salt in water, and iron filings in sand.
She must get one part out of each.
The same method will not work for all three.
How does she pick?
How do you pick a way to separate a mixture?
Find a property that one part has and the other does not.
Sand does not dissolve, so pour the mixture through filter paper and the sand stays behind; that method is called filtering.
Salt is dissolved, so heat the water away and the salt is left behind; that method is called evaporating.
A magnet pulls iron and does not pull sand: use a magnet.
Big pieces and small pieces: a sieve lets only the small ones through.
Video: each separation happening — video and article.
Part 1 — MAT-041 — Select an appropriate separation method for a mixture by matching it to the property difference between its components; coin filtering, evaporating, using a magnet, sieving
Part 1q — Fluency quiz: the four method names
Topic close
Mixed mastery practice: 12 items; the coined terms by typed recall (solution, solute, solvent, concentration, dilute, the four methods); two typed mass calculations; two short written answers (why the hot cup dissolves faster; why the mass adds up).
Then the PP100: 20 four-option MCQs on fresh instances, tagged easy / medium / hard by depth of reasoning, at least one item 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.