Reasoning Starters
FORMULA Scientific Reasoning = General Science Rule + Direct Link to My Evidence
Keep this page next to your lab notebook!
Guided Practice
Follow along as your teacher performs the demonstration
Demo Phase What Did You Observe? (Sights, Sounds, Temperature) Suspected Change
1. Snapping & Crushing
Physical / Chemical?
2. Food Coloring Drop
Physical / Chemical?
3. Tablet in Water
Physical / Chemical?
Step A: State Your Claim (Check one box)
Only Physical Change
Only Chemical Change
Both Physical & Chemical
Step B: List Concrete Evidence (2 specific clues with details)
Evidence for Physical Change:
Evidence for Chemical Change:
Step C: Reasoning (Explain WHY using the "Rule + Link" formula)
Write neatly in complete sentences
Station Rotations
Write your CER paragraph for each mini lab station
1 Station 1 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
2 Station 2 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
3 Station 3 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
4 Station 4 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
Remember: Every paragraph must have Claim, Evidence (clues), and Reasoning (why). Page 3 of 4
Station Rotations
Complete your remaining station investigations
5 Station 5 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
6 Station 6 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
7 Station 7 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
8 Station 8 Name:
Claim: Physical Chemical Both
Clues Observed: [ ] Size[ ] Shape[ ] State[ ] Odor[ ] Color[ ] Temp[ ] Gas[ ] Precipitate
Clear Claim: Did I state physical, chemical, or both in the first sentence?
Specific Evidence: Did I name at least 2 specific clues I saw or measured?
Rule + Link Reasoning: Did I explain whether new substances formed at the atomic level?
"C-Precise:" Check: Did you declare physical, chemical, or both?
"R-Link:" Don't just repeat evidence—explain how it proves a new substance!
Quick-Reference Cheat Sheet
Suggested stations, correct claims, and observable evidence clues
| Station | Setup / Action | Claim | Evidence Clues & Key Reasoning |
|---|---|---|---|
| Stn 1 | Tearing paper & crushing chalk | Physical | Change in size/shape only; no new substance or gas produced. |
| Stn 2 | Baking soda + vinegar in cup | Chemical | Rapid bubbling (gas production) & liquid cools down ($CO_2$ gas formed). |
| Stn 3 | Ice melting under lamp | Physical | State change (solid to liquid); water molecules ($H_2O$) remain unchanged. |
| Stn 4 | Snapping a glow stick | Chemical | Production of light (chemiluminescence) via chemical bond energy release. |
| Stn 5 | Dissolving table salt in water | Physical | Dissolving/mixture; crystal dissolves but can be recovered by evaporation. |
| Stn 6 | Steel wool soaked in vinegar | Chemical | Rusting/oxidation: color changes to reddish-brown; temp rises (exothermic). |
| Stn 7 | Warm milk + vinegar (curdling) | Chemical | Formation of precipitate (solid protein curds form from two liquids); sour odor. |
| Stn 8 | Lit birthday candle / wax | Both | Physical: wax melting (phase change); Chemical: wick burning (flame, smoke, odor). |
Component 4 - Exemplary 3 - Proficient 2 - Developing 1 - Beginning
Claim (C) Precise, accurate declaration of physical, chemical, or both. Accurate claim with minor wording imprecision. Vague claim or misidentifies change. Missing claim or incorrect.
Evidence (E) Cites 2+ specific, observable sensory/data clues (e.g. gas, temp, size). Cites at least 1 accurate clue with general description. Cites inaccurate or subjective clue ("it looked weird"). No evidence provided.
Reasoning (R) Uses "Rule + Link": explains whether new substances formed at molecular level. Links evidence to claim, but omits full scientific rule. Just restates evidence without scientific reasoning. Reasoning is missing or illogical.
Assessment Tip: Grade 2–3 stations in detail per student rather than all 8 to maintain quick turnaround. Change Detective Teacher Key
