Skill: course-build → write-mcqs → write-explanation, design-check-sequence @ 264fe96
Topic 21 — Heating and cooling — the PP100's ten question types, with their exemplars
What this page is. James approves a bank's question TYPES before the bank is generated (vault: A bank is reviewed as its question types first, one exemplar each, 28 Sep 2026). This sheet writes the exemplars in full, exactly as they sit in content/G3T21.py (PP100, flagged TYPE_SHEET_ONLY). Ten types for seven atoms — the ceiling. Seven atoms each need at least one type that tests them alone, and the pairs James asked for (every atom alone AND in twos) need three more; one type (the word for the change, typed) tests five atoms alone by its instances, which is what keeps the count at ten. If you want fewer, type 10 (the wet plate) could fold into type 1 as a liquid-in-the-open instance, and type 4 (the white cloud) could become a second form of type 3. Type 2 carries a second form, so the sheet has eleven exemplars. No other bank item exists yet. Once the types stand, about fifty items are generated from them, varying the things, the scenes and the names, easy-heavy.
Revised 28 Sep 2026 (night) after the non-author review (REVIEW_G3T21_2026-09-28.md, block Q1 and fix Q5): seven exemplars were lesson or quiz items with a noun changed — they are re-instanced on a different scene KIND each (a chocolate coin on a windowsill; a bag of frozen peas; hail on a trampoline; rain on a park slide; an outdoor hot tub; the inside of a tent; beads on a metal railing), the move line kept; PP-1 is singular so the fixed set fits; the design-move inventory below is the check.
James's rulings applied. Hard items are typed, never MCQs (28 Sep night): one text-entry type (the word for the change) and one numeric-entry type (the thermometer reading, with its unit). Easy and medium are four-option MCQs. Every prediction item's drawing is the BEFORE moment only (a scene card), so no drawing hands over its answer; no stem leans on a video; no option bundles a verdict with a reason; every stem is a positive question; every option is a happening, a place or a substance, parallel across the set; every drawn thermometer level is one the scale gives (figures.py asserts it), and the long-tube reading carries Topic 17's magnified strip.
How to read a type line. Each says what the stem asks, what the four options are (the kind of thing), and gives its exemplar scene. Every MCQ has a why (no per-option feedback in the bank; the engine prints Correct / Not quite). Tags follow depth of reasoning: easy = one prediction from one rule on a drawn or named scene; medium = the fact applied to a fresh case, two ideas held apart (the cloud is drops, not vapor; the water came from the air, not through the cloth), or two changes chained (melt, then cool: freeze); hard = the word or the number produced (typed).
The ten types
| Type | Items | Atom | Tag | Form | The stem asks… | The options / the accept | Exemplar scene |
|---|---|---|---|---|---|---|---|
| 1 | PP-1 | MAT3-040 (the flipped instance — a liquid cooling — tests MAT3-041 alone) | easy | MCQ, drawn scene card | a solid warms up (or a liquid cools down): what happens to it | four happenings: It turns into a liquid. / It stays a solid. / It turns into a gas. / It gets bigger. | a chocolate coin on a sunny windowsill |
| 2 | PP-9; PP-11 (second form) | MAT3-045; MAT3-040 (instances test 040, 041, 042, 044, 045 alone) | hard | text | a change described only by what is seen: type the word for it | condensation, condensing…; melting, melt… (TERM_FORMS) | beads of water on a cold metal railing; snow on a warm car roof turning to water |
| 3 | PP-5 | MAT3-043 + MAT3-042 (pair) | medium | MCQ | a wet thing has dried: where is its water now | four places: soaked into the slide / in the air, as water vapor / gone into nothing / turned into air | rain on a park slide, dry an hour later |
| 4 | PP-6 | MAT3-044 + MAT3-043 (pair) | medium | MCQ | a white cloud rises over hot water: what is the cloud | four substances: tiny drops of liquid water / water vapor / smoke / air | an outdoor hot tub on a cold morning |
| 5 | PP-3 | MAT3-045 | easy | MCQ, drawn scene card | a cold thing comes into warm air: what forms on its outside | four things: nothing / drops of water / a white cloud / bubbles | a bag of frozen peas on a warm table |
| 6 | PP-7 | MAT3-045 + MAT3-043 (pair) | medium | MCQ | drops cover a cold surface: where did the drops' water come from | four sources: from the tent cloth / from the ground sheet / from nowhere / from the water vapor in the air | the inside of a tent in the morning |
| 7 | PP-4 | MAT3-046 + MAT3-040 (pair) | easy | MCQ | ice or hail has melted: what is the liquid | four substances: a new kind of liquid / oil / juice / water | hail melting on a trampoline |
| 8 | PP-10 | MAT3-044 + Topic 17's SR3-023 (pair); the 32 °F instance pairs MAT3-041 with SR3-023 | hard | numeric, drawn | a thermometer stands in bubbling water (or in stirred ice and water): read it, type the number of degrees Fahrenheit | acc(212, "F"): 212 and the unit in a child's forms (the second instance acc(32, "F")) | the long-tube thermometer with its magnified strip, in a kettle — the stem and the card do NOT say the water is bubbling (the cold reader's flag: the word handed over 212 without the scale being read) |
| 9 | PP-8 | MAT3-041 + MAT3-040 (pair) | medium | MCQ | a solid melts, and the liquid runs onto something cold: what happens to it there | four happenings: It stays a liquid. / It goes into the air. / It turns into a solid. / It turns into a gas. | candle wax dripping onto a cold plate |
| 10 | PP-2 | MAT3-042 | easy | MCQ | water sits on something open to the air: what happens to the water | four happenings: It stays on the plate. / It turns into ice. / It goes into the air. / It soaks into the plate. | a wet plate on a rack |
Hard because (type 2): the word is produced, not recognised, for a change the stem describes only by what is seen (beads forming on cold metal; snow turning to water) — the student must first decide which change it is, then supply the term. Hard because (type 8): the student performs Topic 17's reading routine on the drawn scale (the number below, count up in 2s) and types the number with its unit; the boiling instance is on the long tube with its magnified 200–220 strip, where the number below the top is 210. Medium because (types 3, 4, 6): two ideas are held apart — the slide's water is water in the air, not air; the cloud can be seen so it is drops, not vapor; the tent cloth and ground sheet are dry, so the drops' water came from the air. Medium because (type 9): two changes are chained — the wax melted (warmed up enough), then cooled on the plate, so it turns solid; a student who stops at "wax melts" picks the liquid.
Coverage (every atom alone, and the pairs)
| Atom | Types testing it alone | Pair types |
|---|---|---|
| MAT3-040 melting | 1, 2 (the melting instance) | 7 (with 046), 9 (with 041) |
| MAT3-041 freezing | 1 (the liquid-cooling instance), 2 | 9 (with 040), 8 (the 32 °F instance, with SR3-023) |
| MAT3-042 evaporation | 10, 2 | 3 (with 043) |
| MAT3-043 where the water went | 3 (the place itself is the atom's fact) | 3 (with 042), 4 (with 044), 6 (with 045) |
| MAT3-044 boiling | 2 | 4 (with 043), 8 (with SR3-023) |
| MAT3-045 condensation | 5, 2 | 6 (with 043) |
| MAT3-046 same water | 7 | 7 (with 040) |
At most two alone-types per atom (James: "unlikely that you're going to need more than two question types per atom"). Order in the file: easy PP-1…PP-4 → medium PP-5…PP-8 → hard PP-9, PP-10, PP-11. Keys of the eight MCQs, in file order: PP-1 A · PP-2 C · PP-3 B · PP-4 D · PP-5 B · PP-6 A · PP-7 D · PP-8 C (two of each letter). Typed items: 3 of 11 on the sheet; in a bank of about fifty, type 2 supplies about ten typed items (two instances per change word, on fresh scenes) and type 8 four to six — alternating the 212 °F long-tube reading with the 32 °F reading on Topic 17's card (stirred ice water in a bucket; a frozen pond's edge), so the bank's type-8 items are not one picture (review F12) — 14–16 typed items in all.
Design-move inventory (the freshness check, one line per item that shares a move)
| Move (what the student does with what) | Lesson-side instances (taught cases, quiz, attached, practice) | Bank exemplar and its scene KIND |
|---|---|---|
| predict what a warming solid does (liquid / solid / gas) | taught: ice pop in the sun, ice cube in a hand, butter in a pan, chocolate bar in a pocket, spoon in the sun · quiz: snowman, rock, crayon on a dashboard, ice cube in lemonade, ice pop in the freezer, candle wax, fork in soup, butter on toast · attached: ice cream in the sun · summary: an ice sculpture at a fair · practice: an ice block on a sidewalk | PP-1 a chocolate coin on a windowsill (indoors, a sweet, a sill — no lesson-side case is indoors on a sill) |
| predict what open water does | taught: puddle, T-shirt, saucer, hair, lidded saucer · quiz: glass on a desk, capped bottle, footprints, fish tank, two towels, paint cup, socks · attached: towel on a hook | PP-2 a wet plate on a rack (washing-up — no lesson-side case) |
| predict what forms on a cold thing in warm air | taught: soda can, window, mirror, glasses, room-warmth can · quiz: iced juice glass, warm mug · attached: cold milk bottle · summary: a cold lunchbox lid · practice: window pane vs radiator, a cold spoon | PP-3 a bag of frozen peas (a soft freezer bag — no lesson-side case is a bag or from the freezer) |
| name the liquid that melted ice or snow leaves | taught: Zosia's ice cube · quiz: Xanthe's ice cube · attached: snow on a step · practice: frost on a car window, a snowball in a pocket | PP-4 hail on a trampoline (hail — no lesson-side case; the surface is a trampoline, not a step, window or pocket) |
| say where a dried thing's water is now | taught: puddle, shirt, saucer, hair · quiz: saucer on a shelf, swimsuit on a chair, chalkboard · attached: towel on a hook · summary: an umbrella in the hall · practice: a bike seat, a mopped hallway (FRQ) | PP-5 rain on a park slide (outdoor play equipment — no lesson-side case; the fourth option "turned into air" is not in the three-option quiz form) |
| name the white cloud over hot water | taught: the pasta pan · quiz: Xander's pan · attached: a kettle · practice: Rhodri's hot bath | PP-6 an outdoor hot tub on a cold morning (outdoors, no stove, no kettle; "hot spring" was the cold reader's unfamiliar-word flag) |
| say where a cold surface's drops came from | taught: the can · quiz: a cold pipe in a basement | PP-7 the inside of a tent (cloth, outdoors — no lesson-side case; the distractors are the tent's own parts) |
| chain melt-then-cool | — (new to the bank) | PP-8 candle wax dripping onto a cold plate |
| produce the word for a change described by what is seen | quiz term items describe each change by its definition, not by a scene | PP-9 beads of water on a cold metal railing (condensation); PP-11 snow on a warm car roof (melting) — neither scene is a lesson-side case |
| read a drawn thermometer and type it | quiz: L02's card at 32 (recall), L05's pot at 212 · practice: stirred ice water at 32 | PP-10 a kettle's water at 212 on the long tube (shares the reading MOVE with L05's pot; the reading is the instance, and the bank alternates it with 32 °F on Topic 17's card) |
Read against each other, the eleven exemplars share no scene, and none is a lesson-side case with a noun changed: the windowsill, the plate rack, the peas bag, the trampoline, the park slide, the hot tub, the tent, the wax and plate, the railing, the kettle's thermometer and the car roof appear nowhere else in the topic (grep of G3T21_lessons.py and G3T21.py on 28 Sep, night, for each scene noun).
The exemplars, in full
Type 1 — PP-1 · MAT3-040 · easy · drawing pp_choc_coin_sill
Stem: A chocolate coin lies on a sunny windowsill. What happens to the chocolate?
- It turns into a liquid. ← key
- It stays a solid.
- It turns into a gas.
- It gets bigger.
Why: The Sun's light carries energy to the chocolate coin. / The chocolate warms up. / When a solid warms up enough, it turns into a liquid. / So the chocolate melts.
Type 10 — PP-2 · MAT3-042 · easy
Stem: A wet plate stands on a rack after washing. What happens to the water on the plate?
- It stays on the plate.
- It turns into ice.
- It goes into the air. ← key
- It soaks into the plate.
Why: The water on the plate is open to the air. / Bit by bit, the water goes into the air: it evaporates. / So the plate dries.
Type 5 — PP-3 · MAT3-045 · easy · drawing pp_peas_bag
Stem: A bag of frozen peas comes out of the freezer onto a warm table. What forms on the outside of the bag?
- nothing
- drops of water ← key
- a white cloud
- bubbles
Why: The room's air has water vapor in it. / The water vapor touches the cold bag and cools down. / When water vapor cools down enough, it turns back into liquid water. / So drops of water form on the bag.
Type 7 — PP-4 · MAT3-046 + MAT3-040 · easy
Stem: Hail melts on a trampoline. What is the liquid on the trampoline?
- a new kind of liquid
- oil
- juice
- water ← key
Why: Hail is water, frozen. / Melting changes water's state, not the stuff. / So the liquid on the trampoline is water.
Type 3 — PP-5 · MAT3-043 + MAT3-042 · medium
Stem: Rain wet a slide in the park, and an hour later the slide is dry. Where is the rain's water now?
- soaked into the slide
- in the air, as water vapor ← key
- gone into nothing
- turned into air
Why: The slide's water evaporated: it went into the air, bit by bit. / Water that evaporates is still there, as tiny pieces far too small to see. / It is not air; it is water in the air. / So the water is in the air, as water vapor.
Medium because: the fact (L04) is applied to a fresh scene, and "turned into air" — the closest wrong belief, met once in L04 — must be told apart from "water in the air".
Type 4 — PP-6 · MAT3-044 + MAT3-043 · medium
Stem: A white cloud rises above an outdoor hot tub on a cold morning. What is the white cloud?
- tiny drops of liquid water ← key
- water vapor
- smoke
- air
Why: Water vapor cannot be seen. / The white cloud can be seen. / So the cloud is not water vapor: it is tiny drops of liquid water, small enough to float.
Medium because: two facts are held apart — what hot water gives off (water vapor) and what can be seen (drops) — and "water vapor" is the register's own trap; the scene has no stove or kettle to cue the lesson.
Type 6 — PP-7 · MAT3-045 + MAT3-043 · medium
Stem: Drops of water cover the inside of a tent in the morning. Where did the drops' water come from?
- from the tent cloth
- from the ground sheet
- from nowhere
- from the water vapor in the air ← key
Why: The tent cloth and the ground sheet are dry. / The air inside the tent has water vapor in it. / The water vapor touched the cold tent cloth, cooled down and condensed into drops. / So the drops' water came from the water vapor in the air.
Medium because: the student must rule out the "came through the cloth" belief and reach back to L04's fact that the air holds water vapor.
Type 9 — PP-8 · MAT3-041 + MAT3-040 · medium
Stem: Wax melts into a liquid near a candle flame, and the liquid wax drips onto a cold plate. What happens to the wax on the plate?
- It stays a liquid.
- It goes into the air.
- It turns into a solid. ← key
- It turns into a gas.
Why: The cold plate cools the liquid wax down. / When a liquid cools down enough, it turns into a solid. / So the wax on the plate freezes: it turns into a solid.
Medium because: two changes are chained (melting, then freezing on the cold plate), and the freezing is of wax at room warmth, not of water in a freezer — the "freezing means very cold" belief is met.
Type 2 — PP-9 · MAT3-045 · hard · text entry
Stem: Beads of water form on a cold metal railing on a spring morning. What is that change called? Type the word.
Accept: TERM_FORMS["condensation"] — condensation · condensing · condense · condenses · condensed · it condenses · it condensed · it is condensing
Why: The morning air has water vapor in it. / The water vapor touches the cold railing, cools down and turns back into drops of liquid water. / That change is called condensation.
Type 8 — PP-10 · MAT3-044 + SR3-023 · hard · numeric entry · drawing therm_tall_pp_kettle
Stem: A thermometer stands in the water in a kettle on the stove. Read it. Type the number of degrees Fahrenheit.
Accept: acc(212, "F") — 212, 212 °F, 212°F, 212° F, 212 F, 212 degrees, 212 degrees F, 212 degrees Fahrenheit, 212 Fahrenheit, 212 degree Fahrenheit
Why: The number below the top is 210. / On the Fahrenheit side each mark is worth 2. / The top is one mark above 210: 212. / So it reads 212 °F, and that is where water boils.
Type 2, second form — PP-11 · MAT3-040 · hard · text entry
Stem: Snow on a warm car roof turns into water. What is that change called? Type the word.
Accept: TERM_FORMS["melting"] — melting · melt · melts · melted · it melts · it melted · it is melting
Why: The snow is a solid. / The warm roof warms it up enough, and it turns into a liquid. / That change is called melting.