Topic 14 — Acids and bases — blueprint for James

What I need from you: 5 decisions

1

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.

2

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.

3

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.

4

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.

5

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

LessonOpens onFormat
L01Acids: the sour familyLemon juice tastes sour.article only
L02Bases: the slippery familyRub a little soapy water between your fingers.article only
L03The pH scaleLemon juice and soda water are both acids.article only
L04Sort with litmus or with pHSuppose you have six unlabeled liquids.article only
L05Add a base to an acid: the pH climbsSuppose too much stomach acid, at pH 2, gives you heartburn.video + article
L06Where the salt comes fromMix 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?

The point, stated first

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

Check: example sequence in one frame ("blue litmus turns red → acid"): vinegar (acid) → lemon juice (acid) → pure water (not: the paper stays blue) → soda water (acid) → soapy water (not) → rule; fluency quiz: acid or not from a litmus result or a taste, 8 quick items, two options; misconception item: a student says every acid is dangerous — the key corrects: vinegar and lemon juice are acids you eat; battery acid is the one that burns

Figure: licensed photo: a lemon, a vinegar bottle, a glass of soda water; SVG: three cups with a blue litmus strip turning red in each and one staying blue in water; table: the cases and their verdicts

Leans on: T3 L01 (a physical property) — one recall question

Part 1q — Fluency quiz: acid, indicator

Check: fluency

Figure: —

Leans on: —

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?

The point, stated first

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

Check: example sequence in the identical frame to L01 ("red litmus turns blue → base"): soapy water (base) → baking soda solution (base) → vinegar (not: the paper stays red) → ammonia cleaner (base) → pure water (not) → rule; fluency quiz: base or not from a litmus result or a feel, 8 quick items, two options; misconception item: a student says a base is a weak kind of acid — the key corrects: bases are the opposite family and turn red litmus blue

Figure: SVG: three cups with a red litmus strip turning blue in each and one staying red in vinegar; table: acid and base lined up, one row each for taste, feel and litmus

Leans on: L01 — one recall question; T3 L01 (a physical property) — one recall question

Part 1q — Fluency quiz: base

Check: fluency

Figure: —

Leans on: —

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?

The point, stated first

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

Check: example sequence on the drawn scale: pH 2 (acidic) → pH 7 (neutral) → pH 12 (basic) → pH 6 (acidic, the boundary) → pH 8 (basic, the boundary) → rule; fluency quiz: acidic / neutral / basic from a pH, 8 quick items, the scale drawn in every stem; then 4 comparison items on a bar chart: which liquid is more acidic?; misconception item: a student says pH 0 means no acid at all — the key corrects: pH 0 is the most acidic end of the scale

Figure: SVG: the pH scale 0 to 14 drawn as a line with lemon juice, soda water and pure water placed on it; table: the household liquids with their pH (lemon juice 2, vinegar 3, soda water 4, pure water 7, baking soda solution 8, soapy water 10, ammonia cleaner 11)

Leans on: L01 and L02 — one recall question each

Part 1q — Fluency quiz: pH, neutral

Check: fluency

Figure: —

Leans on: —

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.

The point, stated first

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

Check: fluency quiz (type a): acid / base / neutral, 10 quick items alternating a litmus clue and a pH clue, the two-clue table supplied in every stem; two items give both clues, which agree

Figure: table: the two clues (litmus, pH) against the three verdicts; SVG: six cups, each with its one clue written beneath

Leans on: L01, L02, L03 — one recall question each

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?

The point, stated first

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

Check: what (the acid's pH after base is added: rises / falls / stays the same) → why (free response) → fluency quiz on direction: 6 quick items, the pH scale drawn in every stem (base into acid: rises; acid into base: falls; a little base into pH 2: still below 7; exactly enough: 7; too much: above 7) → misconception item: a student says any amount of base makes the acid neutral at once — the key corrects: the pH climbs step by step, only the right amount reaches 7 → transfer (a lake made acidic by rain; a farmer spreads lime, a base: what happens to the pH?)

Figure: SVG: the pH scale with an arrow climbing from 2 to 7 and a second arrow going past it; licensed photo: an antacid tablet

Leans on: L03 (the pH scale) — one recall question; T12 L02 (a chemical reaction makes new substances) — one recall question

Part 1q — Fluency quiz: neutralization

Check: fluency

Figure: —

Leans on: —

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?

The point, stated first

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)

Check: what (the two products of a neutralization: a salt and water) → why (free response: where each part of the salt comes from) → misconception item: a student says the salt was already dissolved in the acid — the key corrects: the sodium part came from the base and the chloride part from the acid → transfer (sulfuric acid + potassium hydroxide → potassium sulfate + water: which reactant gave the potassium?)

Figure: SVG: the acid and the base drawn as two-part blocks, the parts swapping partners into salt and water; table: acid, base, salt, water for three neutralizations

Leans on: L05 — one recall question; T12 L05 (the law of conservation of mass) — one recall question; T7 L05 (compound) — one recall question

Part 1q — Fluency quiz: salt

Check: fluency

Figure: —

Leans on: —

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

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.