# Science · Year 8 · optional Days 11–20

Ten **12-minute additions**, not a complete science sequence. The cell, plate, rock, energy and matter diagrams are **original simplified models**. Use no live tissue, unknown chemicals, heat, microscopes without school approval or real hazard prediction. Where a task asks for a test plan, a paper plan is not a conducted investigation. See the [inquiry mat](print/inquiry-mat.pdf), [clean learner copy](LEARNER-COPY.md) and [staff key](TEACHER-KEY.md). Facts and limits are in the [source ledger](SOURCE-AND-RIGHTS.md).

### Day 11 · Cell structures are not whole organisms · AC9S8U01, AC9S8I04
**Kit:** original paper plant/animal outline cards with nucleus, membrane and plant-cell wall labels. 0–2: Name these drawings as models, not microscope views. 2–4: Predict which label belongs to both cell types and which to the plant-card model. 4–10: Place labels, then name one feature omitted by a flat drawing and how a real specimen could be checked under school rules. 10–12: Check: both modeled cells have membranes and nuclei; the wall label belongs to the plant model. **Routes:** move large label cards; trace raised outlines; explain the matches by speech/sign/AAC. **Response move:** if all cells are treated alike, compare the two model boundaries without claiming every living cell has a nucleus. **Home:** sketch a model's missing detail; no sample collection.

### Day 12 · Cells, tissues and a system · AC9S8U02
**Kit:** original cards `muscle cell → muscle tissue → stomach wall → digestive system`, marked simplified. 0–2: Say the chain shows levels, not that one cell alone is an organ. 2–4: Predict where many similar cells work together. 4–10: Order the four cards and give a cautious function link: muscle contraction helps move food; ask what else the full system would need. 10–12: Check: a tissue is made of cells and an organ has multiple tissues. **Routes:** sort large cards; use a text hierarchy; dictate/point to the level chain. **Response move:** if “stomach = one tissue”, insert at least another tissue as an unanswered detail. **Home:** name a model hierarchy in a non-body setting, such as parts of a machine.

### Day 13 · Three ways plates meet · AC9S8U03, AC9S8I04
**Kit:** three original arrow strips: apart, together, past. 0–2: Identify the strips as motion models, not live hazard maps. 2–4: Predict which shows divergent, convergent and transform boundaries. 4–10: Match terms, sketch one possible feature or process for each using the [USGS summary](SOURCE-AND-RIGHTS.md), and name missing evidence (rock ages, earthquakes or mapping) for a real location. 10–12: Check: a transform model slides past; it does not show a gap opening. **Routes:** slide safe paper strips; raised-arrow board; verbal/AAC comparison. **Response move:** if a diagram predicts a real earthquake, separate boundary type from local risk evidence. **Home:** find a labelled geoscience diagram, no field visit.

### Day 14 · Rock pathways have processes and time · AC9S8U04
**Kit:** `sediment / sedimentary / metamorphic / melt / igneous` word cards and process arrows. 0–2: Say the rock cycle has multiple pathways and long timescales. 2–4: Predict what burial/compaction changes and what melting/cooling produces. 4–10: Build two *possible* pathways; label weathering/deposition, heat/pressure and cooling where relevant, then flag that a classroom card sort cannot date or identify an actual rock. 10–12: Check: rock type is not determined by colour alone. **Routes:** arrow cards; tactile sequence; written flow. **Response move:** if every rock must follow one circular order, add an alternative branch. **Home:** draw two possible arrows between named categories, not collect rocks.

### Day 15 · Fresh Science check A · AC9S8U01, AC9S8U03, AC9S8I06
**Kit:** new cell and plate cases in [ASSESSMENT](ASSESSMENT.md). 0–2: Recall model versus real evidence. 2–4: Explain access/output rules without previewing cases. 4–10: Independent first response. 10–12: Collect before discussion; staff checks source and model limits with [key](TEACHER-KEY.md). **Routes:** annotate; tactile cards; exact-word dictated response. **Response move:** reteach one mistaken boundary or cell feature with a new diagram after collection. **Home:** explain why one drawing cannot prove an event.

### Day 16 · Where energy is, where it goes · AC9S8U05
**Kit:** original toy spring-and-paper-flag storyboard; no actual loaded spring. 0–2: Name a compressed spring as a potential-energy model and a moving flag as kinetic. 2–4: Predict a transfer chain when the spring is released in the story. 4–10: Arrange `stored → moving → sound/thermal surroundings` arrows; distinguish transfer from energy disappearing, and identify what the storyboard cannot measure. 10–12: Check: a stationary compressed spring is not “no energy” in this model. **Routes:** arrow tiles; tactile start/finish marks; short spoken/written explanation. **Response move:** if all energy is called kinetic, ask what the compressed state can do next. **Home:** find an everyday energy story without operating a device.

### Day 17 · Element, compound or mixture? · AC9S8U06
**Kit:** original circle-pair diagrams: identical single atoms, identical joined unlike pairs, and two unjoined types; models only. 0–2: Clarify that circle colours are symbols, not proof from appearance. 2–4: Predict which diagram could stand for an element, compound or mixture. 4–10: Sort, explain what bonding/combination the model asserts and what an actual sample would require to classify. Compare a formula label with a model only when supplied; do not infer formula from colour. 10–12: Check: a mixture may contain more than one particle type without all being chemically joined. **Routes:** large magnetic/paper circles; raised paired pieces; text-only descriptors. **Response move:** if “two colours means mixture” despite bonded pairs, ask whether units repeat identically. **Home:** read a packaged ingredient list as a question, no tasting or mixing.

### Day 18 · Change type needs evidence · AC9S8U07, AC9S8I06
**Kit:** paper-only case cards: torn paper, melted ice in a labelled drawing, and an invented laboratory record showing a new substance formed (no procedure). 0–2: Say visible change alone is not a complete chemical test. 2–4: Predict physical versus chemical *candidate* and what would distinguish them. 4–10: Sort with “supported / needs evidence”; tear is a physical change, melting remains water, while the lab record’s claim needs method and product evidence. No reaction is performed. 10–12: Check: colour change alone is not conclusive. **Routes:** case strips; tactile sort; oral/AAC justification. **Response move:** if a new appearance is equated with a new substance, request composition evidence. **Home:** no home chemical experiment.

### Day 19 · An anomaly belongs in the record · AC9S8I05, AC9S8I06
**Kit:** invented device readings for four repeated checks: 8, 9, 41, 8 arbitrary units, with a note “sensor moved before reading 3”. 0–2: Label all data fictional and unit arbitrary. 2–4: Predict which reading merits a method check. 4–10: Plot four dots; describe typical values and anomalous 41 without silently removing it; propose a repeat with sensor position held fixed. 10–12: Check: the note suggests a possible error, not proof of cause. **Routes:** number strips; raised dot plot; dictated analysis. **Response move:** if learner averages away 41, inspect the third method note before summarising. **Home:** explain why a surprising number should be investigated rather than erased.

### Day 20 · Fresh Science check B · AC9S8U05, AC9S8U06, AC9S8I07
**Kit:** new energy/matter case in [ASSESSMENT](ASSESSMENT.md). 0–2: Recall evidence language. 2–4: Give access options but no case hints. 4–10: Independent first response. 10–12: Collect, then use the teacher key to plan a next step. **Routes:** sort model cards; annotate diagram; speech/sign/AAC explanation. **Response move:** if a paper model is called a real measured result, ask what measurement would be needed in a new case. **Home:** name one useful and one missing feature of any model.