# Ten teacher-ready Chemistry starter scripts · 25 minutes each

Every day uses **2 + 4 + 5 + 7 + 4 + 3 = 25 minutes**. Prepare the [model cards](MODEL-CARDS.md), [clean learner pages](LEARNER.md), [daily switchable routes](DAILY-CHOICES.md), [three original print aids](print/TEXT-ALTERNATIVES.md) and [public teacher key](teacher/ANSWER-AND-NEXT.md). Seven minutes is an initial response window, not a speed criterion; add time locally. “Display,” “sample” and “file” below are fictional, paper-only contexts, never collected laboratory materials.

### Day 1 · A ring model is a model

**Target:** describe the nucleus/electron energy-level model and state one limit of drawn rings. **Prepare:** Cards A/F and [atom model mat](print/atom-model.svg).

1. **Launch · 2 min.** Show the mat's unlabelled circle/dot convention and ask what a line around a nucleus might mean; do not accept “literal track” as observation.
2. **Model · 4 min.** Mark nucleus inside and electrons outside on a word diagram. Explain that distinct energy levels are the *teaching representation*; the rings are not measured paths.
3. **Guided reading · 5 min.** Read Card A in pairs. Distinguish a proton's positive charge, neutron's zero and electron's negative charge; keep actual energy/orbital calculations outside this session.
4. **Practice route · 7 min.** Choose Day 1 route. Annotate/build/explain a fictional museum atom model with the three particle locations/charges and one diagram limit.
5. **Audit · 4 min.** Partner says “electrons drive around the drawn circle.” Learner replaces it with an appropriately bounded model statement.
6. **Exit · 3 min.** “What is inside the nucleus?” Key: protons and neutrons in this model; electrons are represented outside at energy levels.

### Day 2 · Z decides the element

**Target:** use atomic number Z to find proton count and identify carbon Z 6, oxygen Z 8 and magnesium Z 12. **Prepare:** Cards B/D, [count mat](print/count-mat.svg) and the three given Z values; no full periodic table needed.

1. **Launch · 2 min.** Put two anonymous paper tokens marked Z 6 and Z 8 on a recycling-display mock-up. Ask whether colour or proton count decides the element.
2. **Model · 4 min.** Write `Z = protons`; carbon Z 6 has six protons even if the display calls it fibre. Oxygen Z 8 has eight.
3. **Guided reading · 5 min.** Use the given symbol/Z pairs C 6, O 8, Mg 12. If proton count becomes 12 rather than 6, the element is magnesium, not a changed isotope of carbon.
4. **Practice route · 7 min.** Choose Day 2 route; classify the three given labels by Z and explain why a story label is not chemical evidence.
5. **Audit · 4 min.** Peer swaps the words carbon/oxygen while retaining Z; learner repairs by checking the source Z/symbol pair.
6. **Exit · 3 min.** “A neutral atom has Z 6; how many protons?” Key: six; Z alone does not give neutrons.

### Day 3 · A counts two nuclear particles

**Target:** calculate neutrons using A − Z and distinguish mass number from standard atomic weight. **Prepare:** Cards B/D, count mat; examples carbon-12 (A 12 Z 6), oxygen-16 (A 16 Z 8), magnesium-24 (A 24 Z 12).

1. **Launch · 2 min.** Offer `A = protons + neutrons` and ask which count must be known before subtraction.
2. **Model · 4 min.** Carbon-12: p 6, n 12 − 6 = 6. A is an integer count for this isotope, not a decimal average from a periodic-table tile.
3. **Guided reading · 5 min.** Work oxygen-16: n 16 − 8 = 8. Let learners check by adding p + n = 16, then inspect magnesium-24 without supplying its answer.
4. **Practice route · 7 min.** Choose Day 3 route; derive all three p/n counts and explain which number a rounded periodic weight cannot substitute for.
5. **Audit · 4 min.** Partner proposes n = A + Z; learner tests carbon-12 and repairs with reverse-addition evidence.
6. **Exit · 3 min.** “Magnesium-24 with Z 12: neutrons?” Key: 12; explain 12 + 12 = 24.

### Day 4 · Isotopes share identity, not neutrons

**Target:** compare neutral carbon-12/carbon-13 and chlorine-35/chlorine-37 by Z, A and neutron count. **Prepare:** Cards D/E and [isotope/ion fork](print/isotope-ion-fork.svg); give chlorine Z 17.

1. **Launch · 2 min.** Ask whether carbon-13 must have more protons than carbon-12 because “13 is larger.”
2. **Model · 4 min.** Same carbon Z 6 means six protons. Carbon-12 has 6 neutrons; carbon-13 has 7. Isotope difference is nuclear neutron count.
3. **Guided reading · 5 min.** Contrast chlorine-35/37: both Z 17, neutrons 18/20. These are isotope names, not evidence of their natural abundance or chemical safety.
4. **Practice route · 7 min.** Choose Day 4 route; compare both pairs using a shared-Z statement, two neutron calculations and a bounded conclusion.
5. **Audit · 4 min.** Peer calls carbon-12 and magnesium-24 isotopes because both are “atoms”; learner repairs by testing Z.
6. **Exit · 3 min.** “Which count differs within an isotope pair?” Key: neutron count (and A), while proton count/Z stays the same.

### Day 5 · Public fresh check A: a new isotope archive

**Target:** independently transfer Z/A and isotope comparison to [new Files R/S](STUDENT-CHECKS.md#day-5-check-a--boron-archive-files). The check and worked key are public, so it is formative only. **Prepare:** new case, neutral count mat, support log.

1. **Launch · 2 min.** State the task: derive counts, compare two records, and refuse one unsupported claim.
2. **Source access · 4 min.** Release Files R/S without the key; note read-aloud, scribing or other access support.
3. **Independent plan · 5 min.** Learner marks each given Z/A/status, identifies the subtraction, and notes one claim the files cannot prove.
4. **Independent response · 7 min.** Choose Day 5 route and capture a first response; do not supply worked counts during this window.
5. **Self-audit · 4 min.** Learner checks `p+n=A`, neutral `e=p` and same-Z isotope reasoning.
6. **Submit · 3 min.** Collect first response/support log; consult the public key for the next teaching move.

### Day 6 · Read a nuclear symbol without guessing mass

**Target:** read/write the left A-over-Z symbol as full words and derive a neutral magnesium-26 and sodium-23 count. **Prepare:** Card C and count mat; give Mg Z 12 and Na Z 11.

1. **Launch · 2 min.** Show `^{26}_{12}Mg` beside “magnesium-26, Z 12, neutral.” Ask which is isotope mass number versus element identifier.
2. **Model · 4 min.** Translate top-left A 26 and bottom-left Z 12; p 12, n 14, neutral e 12. The written convention is a model/notation, not a physical picture.
3. **Guided reading · 5 min.** Read `^{23}_{11}Na` as sodium-23, Z 11, neutral *for this task*. Derive p 11, n 12, e 11. Model an accessible spoken sequence: “name, A, Z, charge.”
4. **Practice route · 7 min.** Choose Day 6 route; translate both symbols in both directions and check derived counts.
5. **Audit · 4 min.** Partner reads 26 as number of protons. Learner identifies position and verifies n = 26 − 12.
6. **Exit · 3 min.** “Where does A sit in nuclear notation?” Key: upper left of X; Z lower left.

### Day 7 · A positive ion has fewer electrons

**Target:** keep the nucleus fixed while finding electron counts for sodium-23 1+ and magnesium-24 2+. **Prepare:** Cards B/C/D, count mat and isotope/ion fork.

1. **Launch · 2 min.** Place two paper cards “neutral sodium-23” and “sodium-23 1+.” Ask what changed if the isotope name stayed fixed.
2. **Model · 4 min.** Sodium Z 11: neutral e 11; 1+ has e 10. Protons remain 11, neutrons 23 − 11 = 12. One electron lost produces net positive charge.
3. **Guided reading · 5 min.** Magnesium-24 Z 12: neutral e 12; 2+ has e 10, while p/n remain 12/12. Do not teach a mechanism for a real reaction from this count alone.
4. **Practice route · 7 min.** Choose Day 7 route; compare both neutral-to-ion pairs and state what stayed fixed.
5. **Audit · 4 min.** Peer subtracts one proton to make 1+. Learner corrects: electron loss changes charge, proton loss changes element.
6. **Exit · 3 min.** “Magnesium-24 2+: electrons?” Key: 10, with 12 protons and 12 neutrons.

### Day 8 · A negative ion has more electrons

**Target:** calculate electron gain for chlorine-35 1− and oxygen-16 2−, preserving A/Z. **Prepare:** Cards B/D and count mat; O Z 8, Cl Z 17.

1. **Launch · 2 min.** Compare neutral chlorine-35 with a 1− card. Ask whether adding one electron changes its isotope name.
2. **Model · 4 min.** Chlorine-35: p 17, n 18, neutral e 17; 1− e 18. Addition of an electron leaves A 35 and Z 17 fixed.
3. **Guided reading · 5 min.** Oxygen-16 2−: p 8, n 8, e 10. Use charge as a check: eight positive protons against ten negative electrons gives net 2−.
4. **Practice route · 7 min.** Choose Day 8 route; derive both full count triples, then describe electron gain with a qualifier that this is a paper species card.
5. **Audit · 4 min.** Peer uses 2− as “lose two neutrons”; learner repairs with p/n/e and charge bookkeeping.
6. **Exit · 3 min.** “What stayed the same from neutral oxygen-16 to its 2− ion?” Key: p 8, n 8, Z 8, A 16 and element/isotope name.

### Day 9 · Catch four attractive wrong claims

**Target:** detect and correct isotope, ion, notation and evidence errors across new story labels. **Prepare:** Cards B/C/E/F and isotope/ion fork.

1. **Launch · 2 min.** Show “A plus sign means add a proton.” Ask learners to reserve judgement until they check the model rule.
2. **Model · 4 min.** Correct to “for a monoatomic 1+ ion of the same isotope, one electron has been lost.” Explicitly state that an actual process cannot be inferred from a printed symbol alone.
3. **Guided reading · 5 min.** Audit three more statements: “C-12 and C-13 are different elements,” “23 on sodium is its atomic number,” and “a material label proves purity.” Mark rule or evidence source for each repair.
4. **Practice route · 7 min.** Choose Day 9 route; produce four corrected claim/evidence/limit triples. Use a fictional bicycle-parts catalogue label as a *story*, not a product specification.
5. **Audit · 4 min.** Partner checks each correction against `Z→identity`, `A−Z→n`, and `charge→e` while watching for unsupported product inference.
6. **Exit · 3 min.** “What extra information is required to know neutron count from Z alone?” Key: A of a particular isotope.

### Day 10 · Public fresh check B: two new charged species cards

**Target:** independently transfer nuclear-symbol, isotope and charge bookkeeping to [new Files T/U](STUDENT-CHECKS.md#day-10-check-b--two-charged-species-files). Both prompt and key are public. **Prepare:** new case, blank count mat and support log.

1. **Launch · 2 min.** State task: derive p/n/e twice, read status from the symbol, and explain one distinction and one limit.
2. **Source access · 4 min.** Release T/U without the key; record any reading/communication support.
3. **Independent plan · 5 min.** Learner marks left A/Z and right charge separately; calculates n = A − Z and electron change.
4. **Independent response · 7 min.** Choose Day 10 route; capture first work before feedback. More time can follow for instruction.
5. **Self-audit · 4 min.** Learner checks p+n=A and p−e=charge for each record; avoid any real safety inference.
6. **Submit · 3 min.** Retain first response/support record, then use public key for targeted next move. No QCAA unit grade follows.

SubjectNest original teacher scripts © NeuroForgeIO Pty Ltd 2026, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).