Bonding, Formulas & Molecular Structure — Extension · Physical Science: Chemistry, Grade 11
Build names, formulas, Lewis structures, and structure-property explanations.
Bond Models and Material Properties
Investigate
Can structure explain a set of provided property observations?
Use two dedicated sessions: first define the model, boundary, variables and comparison, then collect suitable records or analyze the complete supplied-data route; second complete calculations/graphs, compare alternatives, revise and prepare the report. Extend collection time where needed. Supplied-data work does not certify supervised laboratory minutes or mandated investigations.
Materials
- Paper property cards
- Molecular sketches and periodic table
Before you begin
Use only the listed household materials or analyze the supplied data. An adult should review setup. No flames, strong acids/alkalis, unknown chemicals, household mains, radiation sources, or high-speed projectiles are needed. Keep food-study materials separate from eating and wash hands afterward.
Plan a fair test
Compare composition and structure; property values are supplied under comparable conditions.
Method
- Write a prediction and the physical/chemical mechanism behind it.
- Draw the setup or system boundary; label variables and units.
- Make Lewis/ion models for water, CO₂, NaCl, and copper.
- Predict polarity and charge mobility before viewing the data.
- Compare predictions with observations and explain an exception to a simple rule.
- Record repeated observations where possible; keep original readings and note resolution or uncertainty.
- Write a claim supported by specific numbers, explain the mechanism, and identify one limitation and a next test.
Example data — for analysis when materials are unavailable
Illustrative teaching data, not measurements from a real district laboratory. Analyze these when materials are unavailable and identify them as provided data. Do not claim to have performed a measurement you did not make.
| Material | Solid conducts? | Dissolved/molten conducts? | Structural clue |
|---|---|---|---|
| NaCl | No | Yes | Ionic lattice |
| Copper | Yes | Yes molten | Delocalized electrons |
| CO₂ | No | No pure substance | Linear molecule |
Analyze and explain
- Why do polar CO₂ bonds not imply molecular polarity?
- Which charge carriers move in salt and copper?
- Why cannot molecular boiling data alone identify bond type?
- Link the pattern to a labeled particle, structure, energy or amount model from the chapter.
- Distinguish supplied illustrative records from measurements actually collected.
- Identify uncertainty and propose a comparison that would test an alternative explanation.
What a strong explanation includes
- A stated prediction, conditions, and controlled variables or explicit model boundary.
- A labeled table/graph with units, calculations, and attention to repeated values or uncertainty.
- A claim citing numerical evidence and a scientifically accurate mechanism.
- A limitation, alternative explanation, and useful follow-up test.
- Preserve initial reasoning and an evidence-supported revision.
- Check units, species identity, system boundary and physical assumptions.
Parent / teacher guide: discuss after the investigation
CO₂ bond dipoles cancel in its linear geometry. Salt conduction requires mobile ions, while copper has mobile electrons in the solid. Property predictions require structure and phase; a single property is not a unique identity test. Preserve the original observations, intermediate working and a labeled mechanism. Report the relevant boundary and model assumptions, discuss an alternative explanation, and identify the next useful measurement; do not replace unexpected data with the illustrative record.
Compare this model with the learner’s actual evidence. Different measurements can support a different conclusion; check the reasoning and limitations, not matching wording.
Extend the chapter investigation by evaluating its evidence and proposing a better test.
Problem 1
Answer and explanation
CO₂ bond dipoles cancel in its linear geometry. Salt conduction requires mobile ions, while copper has mobile electrons in the solid. Property predictions require structure and phase; a single property is not a unique identity test. Preserve the original observations, intermediate working and a labeled mechanism. Report the relevant boundary and model assumptions, discuss an alternative explanation, and identify the next useful measurement; do not replace unexpected data with the illustrative record.
Problem 2
Answer and explanation
CO₂ bond dipoles cancel in its linear geometry. Salt conduction requires mobile ions, while copper has mobile electrons in the solid. Property predictions require structure and phase; a single property is not a unique identity test. Preserve the original observations, intermediate working and a labeled mechanism. Report the relevant boundary and model assumptions, discuss an alternative explanation, and identify the next useful measurement; do not replace unexpected data with the illustrative record.
Problem 3
Answer and explanation
CO₂ bond dipoles cancel in its linear geometry. Salt conduction requires mobile ions, while copper has mobile electrons in the solid. Property predictions require structure and phase; a single property is not a unique identity test. Preserve the original observations, intermediate working and a labeled mechanism. Report the relevant boundary and model assumptions, discuss an alternative explanation, and identify the next useful measurement; do not replace unexpected data with the illustrative record.
Problem 4
Answer and explanation
CO₂ bond dipoles cancel in its linear geometry. Salt conduction requires mobile ions, while copper has mobile electrons in the solid. Property predictions require structure and phase; a single property is not a unique identity test. Preserve the original observations, intermediate working and a labeled mechanism. Report the relevant boundary and model assumptions, discuss an alternative explanation, and identify the next useful measurement; do not replace unexpected data with the illustrative record.
Problem 5
Answer and explanation
CO₂ bond dipoles cancel in its linear geometry. Salt conduction requires mobile ions, while copper has mobile electrons in the solid. Property predictions require structure and phase; a single property is not a unique identity test. Preserve the original observations, intermediate working and a labeled mechanism. Report the relevant boundary and model assumptions, discuss an alternative explanation, and identify the next useful measurement; do not replace unexpected data with the illustrative record.
Problem 6
Answer and explanation
CO₂ bond dipoles cancel in its linear geometry. Salt conduction requires mobile ions, while copper has mobile electrons in the solid. Property predictions require structure and phase; a single property is not a unique identity test. Preserve the original observations, intermediate working and a labeled mechanism. Report the relevant boundary and model assumptions, discuss an alternative explanation, and identify the next useful measurement; do not replace unexpected data with the illustrative record.