Topic 14 — Acids and bases — blueprint for James
What I need from you: 5 decisions
Use litmus paper as the only indicator, with a pH meter for the pH itself?
the register names litmus (MAT-082) and "indicator results" (MAT-077, 078); grade-8 tests give a litmus color or a pH, not a red-cabbage chart.
one indicator means one thing to remember: blue litmus turns red in an acid, red litmus turns blue in a base.
My recommendation: litmus only, plus a pH meter for the scale; no universal indicator or cabbage juice. Agree / add universal indicator.
Place the litmus-or-pH sorting routine (L04) before the two neutralization lessons?
MAT-082 sorts a liquid into acid, base or neutral from either clue; it needs only L01 to L03, and it is the item grade-8 tests ask most.
the two neutralization lessons (what happens to pH; where the salt comes from) are a story of their own and read better together at the end.
My recommendation: L04 the sort, then L05 and L06 the reaction. Agree / reaction first.
Trace the salt's two parts to the acid and the base without naming ions?
MAT-080 asks where the salt in a neutralization comes from; the honest answer is that the base gives its metal part and the acid gives the rest, and the leftovers make water.
"part" is the word; ions, H⁺ and OH⁻ are high school, and Topic 8 gave the student nothing to build them from.
My recommendation: "the sodium part from the base, the chloride part from the acid"; no ions. Agree / name ions once.
Say "more acidic" for a lower pH, and keep "strong" only for the safety lines?
in chemistry "strong acid" means something the student will not meet until high school; on this page a lower pH simply means more acidic.
the safety lines still need an everyday word for battery acid and drain cleaner, and "strong" is the word a student already uses.
My recommendation: "more acidic / more basic" in the teaching; "strong" only in the safety lines. Agree / use "strong" freely.
Which lessons could do without a video?
L05 (the pH climbing along the scale as base is added) and L06 (the acid's and base's parts swapping partners) have something to watch; L01 to L04 are two example sequences, a scale and a sort.
My recommendation: mark L01, L02, L03 and L04 "could do without a video"; all six scripted. Agree / change.
Topic 14 at a glance — 6 lessons
| Lesson | Opens on | Format | |
|---|---|---|---|
| L01 | Acids: the sour family | Lemon juice tastes sour. | article only |
| L02 | Bases: the slippery family | Rub a little soapy water between your fingers. | article only |
| L03 | The pH scale | Lemon juice and soda water are both acids. | article only |
| L04 | Sort with litmus or with pH | Suppose you have six unlabeled liquids. | article only |
| L05 | Add a base to an acid: the pH climbs | Suppose too much stomach acid, at pH 2, gives you heartburn. | video + article |
| L06 | Where the salt comes from | Mix hydrochloric acid with sodium hydroxide, a base, in just the right amounts. | video + article |
What this topic is, in five lines
Six lessons, one per atom, in teaching order: MAT-077, 078, 079, 082, 081, 080.
Terms coined here: acid, indicator, litmus paper (L01), base (L02), pH, neutral, acidic, basic (L03), neutralization (L05), salt in its chemistry sense (L06).
Deliberately not taught: ions, hydrogen and hydroxide ions, strong against weak acids, concentration, the pH scale as powers of ten, titration, universal indicator.
An intro video (under 120 words, teaches nothing) opens the topic; a summary video (everything taught, in order, with its own easy question) sits just before the PP100.
The PP100 draws 20 items, tagged easy / medium / hard by depth of reasoning, from a bank of at least 50 four-option MCQs on fresh instances.
Acids: the sour family L01
Lemon juice tastes sour.
Vinegar tastes sour.
Soda water tastes sharp and sour too.
Dip a strip of blue litmus paper into each one.
Each strip turns red.
Three different liquids turn the paper the same color.
What do they have in common?
How do you know a substance is an acid?
Acids share a set of properties.
They taste sour.
They turn blue litmus paper red.
A substance with these properties is called an acid.
Litmus paper is called an indicator.
An indicator changes color to show which family a liquid belongs to.
Some acids, like the sulfuric acid in a car battery, burn skin.
So in a lab the test is litmus, never taste.
Video: nothing a page cannot show — article only (could do without a video).
Part 1 — MAT-077 — Identify a substance as an acid from its observable properties or indicator results; coin acid, indicator, litmus paper
Part 1q — Fluency quiz: acid, indicator
Notes
Safety: this page names sulfuric acid; the safety line says never taste or touch a liquid to test it, and that battery acid burns skin.
Bases: the slippery family L02
Rub a little soapy water between your fingers.
It feels slippery.
Baking soda dissolved in water feels slippery too.
It tastes bitter.
Dip a strip of red litmus paper into each one.
Each strip turns blue.
Acids turned blue litmus red.
These liquids do the opposite.
What are they?
How do you know a substance is a base?
Bases share a set of properties.
They feel slippery between your fingers.
They taste bitter.
They turn red litmus paper blue.
A substance with these properties is called a base.
Some bases, like the sodium hydroxide in drain cleaner, burn skin as badly as a strong acid.
So the lab test is litmus, never touch or taste.
Video: nothing a page cannot show — article only (could do without a video).
Part 1 — MAT-078 — Identify a substance as a base from its observable properties or indicator results; coin base
Part 1q — Fluency quiz: base
Notes
Safety: this page names sodium hydroxide; the safety line says drain cleaner burns skin and eyes, and that no liquid is touched or tasted to test it.
The pH scale L03
Lemon juice and soda water are both acids.
Yet lemon juice tastes far more sour.
Litmus paper turns red in both and cannot tell them apart.
A pH meter dipped in lemon juice shows pH 2.
Dipped in soda water it shows pH 4.
Dipped in pure water it shows pH 7.
What does the pH tell you?
How do you say how acidic or how basic a liquid is?
Chemists use a scale from 0 to 14 called the pH scale.
Pure water sits in the middle at pH 7 and is called neutral.
Below 7 the liquid is acidic.
The lower the pH, the more acidic the liquid is.
Above 7 the liquid is basic.
The higher the pH, the more basic the liquid is.
Video: nothing a page cannot show — article only (could do without a video).
Part 1 — MAT-079 — Classify a substance as acidic, neutral, or basic given its pH value, using water as the neutral reference point; coin pH, neutral, acidic, basic
Part 1q — Fluency quiz: pH, neutral
Sort with litmus or with pH L04
Suppose you have six unlabeled liquids.
For three of them, you have only a litmus test.
For the other three, you have only a pH.
Sort all six into acid, base or neutral.
How do you sort a liquid when you have one clue?
If the clue is litmus, read the color change.
Blue litmus turning red means acid.
Red litmus turning blue means base.
Neither paper changing means neutral.
If the clue is a pH, read the scale.
Below 7 means acid.
Exactly 7 means neutral.
Above 7 means base.
Either clue lands the liquid in the same three boxes.
Video: nothing a page cannot show — article only (could do without a video).
Part 1 — MAT-082 — Classify a substance as acid, base, or neutral using either a litmus result or a pH value
Add a base to an acid: the pH climbs L05
Suppose too much stomach acid, at pH 2, gives you heartburn.
You chew two antacid tablets.
The tablets are a base.
The burning eases.
What did the base do to the acid's pH?
What happens to the pH of an acid when you add a base?
The base reacts with the acid.
The reaction uses up some of the acid.
Less acid means the pH climbs toward 7.
Add exactly enough base.
The pH reaches 7.
The liquid is now neutral.
Add more base than that.
The pH climbs past 7 into the basic side.
This reaction is called neutralization.
Video: a marker climbing the drawn pH scale from 2 toward 7 as base is poured in, then past 7 when too much goes in — video and article (definitely a video).
Part 1 — MAT-081 — Predict how the pH of an acidic solution changes when a base is added to it; coin neutralization
Part 1q — Fluency quiz: neutralization
Notes
Safety: this page names hydrochloric acid (stomach acid is dilute hydrochloric acid); the safety line says hydrochloric acid from a bottle burns skin, so goggles and gloves are worn.
Where the salt comes from L06
Mix hydrochloric acid with sodium hydroxide, a base, in just the right amounts.
The mixture reaches pH 7.
Boil the water away until only crystals are left.
The crystals are white.
The crystals are sodium chloride, table salt.
Neither the acid nor the base was salty.
Where did the salt come from?
Where does the salt in a neutralization come from?
Its atoms come from both reactants.
The base gives its metal part, sodium.
The acid gives its other part, chloride.
Sodium and chloride join to make sodium chloride, the salt.
The leftover parts, hydrogen from the acid and hydroxide from the base, join to make water.
In chemistry "salt" names a whole family of substances made this way.
Table salt is just one member of the family.
No atom appeared or vanished.
Every atom in the salt and the water was there in the acid or the base.
Video: the acid's and base's parts drawn as blocks swapping partners into salt and water — video and article (definitely a video).
Part 1 — MAT-080 — Explain where the salt formed in an acid–base reaction comes from; coin salt (chemistry sense)
Part 1q — Fluency quiz: salt
Notes
Safety: this page names hydrochloric acid and sodium hydroxide; the safety line says both burn skin and eyes, so goggles and gloves are worn and the mixing is done by the teacher.
Topic close
Mixed mastery practice: 12 items; the coined terms by typed recall; four litmus-or-pH sorts; two pH-direction predictions; one short written answer (where the salt's two parts come from).
Then the PP100: 20 items drawn from a bank of at least 50 four-option MCQs on fresh liquids and fresh pH readings, tagged easy / medium / hard by depth of reasoning, at least three per atom, the pH scale drawn in every stem that needs it.
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.