Topic 6 — Solutions and separating mixtures — blueprint for James

What I need from you: 4 decisions

1

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.

2

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.

3

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.

4

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

LessonOpens onFormat
L01What a solution isA student stirs a spoon of sugar into a glass of water until it vanishes.video + article
L02Solute and solventA label on a bottle reads: "salt water — 10 g of salt in 500 mL of water".article only
L03How concentrated?Three glasses each hold 200 mL of water.article only
L04Adding water: dilutionA glass holds a strong, dark cordial: 40 g of syrup in 200 mL of water.video + article
L05Mass adds up when a solution formsA student weighs 200 g of water in a beaker.video + article
L06Dissolving faster: warmer waterTwo cups each hold 200 mL of water and one sugar cube.video + article
L07Dissolving faster: smaller piecesTwo cups each hold 200 mL of water at 20 °C.video + article
L08Dissolving faster: stirringTwo cups each hold 200 mL of water at 20 °C and one sugar cube.video + article
L09Choose a way to separate a mixtureA 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?

The point, stated first

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

Check: example sequence: solution (sugar water) → solution (salt water) → not a solution (flour and water) → solution (drink powder in water) → not a solution (sand in water) → rule; fluency quiz: solution or not, 8 fresh cases; misconception item: a student says the sugar is gone — the key corrects: it is spread through the water as particles

Figure: SVG: two particle boxes — sugar particles spread evenly among water particles; flour grains as clumps settling

Leans on: T5 L04 (homogeneous mixture) and T3 L04 (soluble) — one recall question each; MAT4-022 retrieved

Part 1q — Fluency quiz: solution

Check: fluency

Figure: —

Leans on: —

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?

The point, stated first

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

Check: fluency quiz: name the solute / name the solvent in 8 fresh solutions (sugar in tea, drink powder in water, salt in sea water, carbon dioxide in soda water…); one two-option item per solution

Figure: table: five solutions with solute and solvent columns

Leans on: L01 (solution) — one recall question

Part 1q — Fluency quiz: solute / solvent

Check: fluency

Figure: —

Leans on: —

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?

The point, stated first

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

Check: fluency quiz: which of two is more concentrated, 6 pairs in small tables (same solvent, different solute; same solute, different solvent); then "most" and "least" on a three-row table (two plain items)

Figure: table: solute mass (g) and solvent volume (mL) for each glass, ordered

Leans on: L02 (solute, solvent) — one recall question

Part 1q — Fluency quiz: concentration (the plain meaning)

Check: fluency

Figure: —

Leans on: —

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?

The point, stated first

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

Check: what (juice topped up with water: concentration up / down / same) → why (free response) → misconception item: a student says adding water washes some syrup away — the key corrects: the syrup is all still there, spread through more water → transfer (soup with extra water)

Figure: SVG: two particle boxes, the same 8 solute particles among 16 then 32 solvent particles

Leans on: L03 (concentration) — one recall question

Part 1q — Fluency quiz: dilute

Check: fluency

Figure: —

Leans on: —

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?

The point, stated first

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

Check: scaffolded (type b): worked example on the page → step items on a fresh case (the two masses; add; unit) → three typed numeric items, one with surplus information

Figure: SVG: the balance before (water 200 g) and after (solution 215 g) with the salt paper beside

Leans on: L01 (a solution: the solute is still there) and T2 L07 (mass holds) — one recall question each; MAT5-061 retrieved

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?

The point, stated first

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

Check: what (salt in cold vs warm water: which dissolves faster) → why (free response) → misconception item: a student says hot water dissolves more because it is "thinner" — the key corrects: its particles move faster → transfer (drink powder in iced vs hot water)

Figure: table: the two cups — water volume, temperature, time to dissolve; SVG: two liquid boxes with short and long arrows around a cube

Leans on: T1 L04 (heating speeds particles) — one recall question; MAT5-025 retrieved

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?

The point, stated first

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

Check: what (a bath bomb whole vs crumbled) → why (free response) → misconception item: a student says the grains dissolve faster because there is less sugar — the key corrects: the same mass, more surface → transfer (coarse vs fine salt)

Figure: SVG: one cube and the same volume as eight small cubes, surfaces highlighted

Leans on: L06 (water particles knock solute particles off the surface) — one recall question

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?

The point, stated first

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

Check: what (salt in a shaken vs still bottle) → why (free response) → misconception item: a student says stirring dissolves more sugar in total — the key corrects: stirring changes the speed, not the amount → transfer (drink powder, stirred or not)

Figure: SVG: two cups, one with a spoon and swept water; table: the three speed-ups (warmer, smaller pieces, stirring) side by side

Leans on: L06 — one recall question

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?

The point, stated first

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

Check: scaffolded: worked walk (name the two parts; name the property only one has; pick the method) → step items on a fresh mixture → fluency quiz: pick the method, 8 fresh mixtures

Figure: table: four methods — the property difference each uses and one example; SVG: the four set-ups drawn simply

Leans on: T5 L03 (each part keeps its properties) and L01 (dissolved) — one recall question each; FOR-017 (a magnet pulls iron) stated in one sentence; MAT5-024 retrieved

Part 1q — Fluency quiz: the four method names

Check: fluency

Figure: —

Leans on: —

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

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.