Parent plan · Week 5 · Atoms, Electrons & Periodicity — connect, calculate and revise — Physical Science: Chemistry

Units to teach or revisit

Chapter 2 · Atoms, Electrons & Periodicity

Assigned readings

From a spectrum to an atomic model

Develop this chapter question: How does atomic structure explain chemical patterns?

This week’s goals

Explain models, species, arrows and axes before substituting values.
Conserve the relevant atoms, charge, amount and energy account.
Apply independently, state limits and revise from evidence.

Read From a spectrum to an atomic model at chapter launch and revisit it alongside this week’s linked units, figures and investigation.

Five flexible sessions, normally 50–60 minutes. Two core unit sessions are scheduled, with a third for selected demanding topics. Sample week uses a complete 90-minute paper plus about 30 minutes of corrections within two ordinary-hour equivalents.

Session 1 · Periodic Trends — apply and explain

Use the linked chapter reading, unit explanations, figures and notebook.

Your task

Study Parts 3–4 and selected source-model prompts, then attempt the whole-unit application, illustrated practice and changed independent case. Explain a correction, revise the opening model and complete the exit check.

Prepare the assigned explanation and identify the question.
Trace a model or graph, labeling its species and units.
Attempt the assigned reasoning and calculation before opening guidance.
Compare with criteria and retain an explained correction.

Hint and response guidance

Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.

All have ten electrons; proton counts are F=9, Ne=10, Mg=12. The usual order is F⁻ > Ne > Mg²⁺ under a compatible radius comparison. Defined atomic/ionic radii and environments must be matched before treating reference numbers as directly interchangeable.

Use the supplied evidence and correct species/units.
Explain the relevant mechanism or relationship.
Show intermediate working or a labeled model.
State an assumption, limitation or useful next test.

Session 2 · Extended calculation and transfer — Periodic Trends

Use the linked chapter reading, unit explanations, figures and notebook.

Your task

Reconstruct a worked method without looking at its answer. Then solve this changed case, show intermediate steps and units, explain a limit and compare a second method where appropriate: Rank Ne, F⁻ and Mg²⁺ by the usual radius trend for an isoelectronic series. Give electron/proton counts and the model limitation.

Prepare the assigned explanation and identify the question.
Trace a model or graph, labeling its species and units.
Attempt the assigned reasoning and calculation before opening guidance.
Compare with criteria and retain an explained correction.

Hint and response guidance

Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.

Use the supplied evidence and correct species/units.
Explain the relevant mechanism or relationship.
Show intermediate working or a labeled model.
State an assumption, limitation or useful next test.

Session 3 · Electron Transitions & Emission Spectra — build the model

Use the linked chapter reading, unit explanations, figures and notebook.

Your task

Read the chapter background and unit language. Draw a first model, study the core explanation and Parts 1–2, trace each figure and attempt the visual questions/checks. Complete a first worked case with its answer covered.

Prepare the assigned explanation and identify the question.
Trace a model or graph, labeling its species and units.
Attempt the assigned reasoning and calculation before opening guidance.
Compare with criteria and retain an explained correction.

Hint and response guidance

Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.

3 eV, the positive difference between the initial and final state energies. It halves, because λ=hc/E with h and c fixed.

Use the supplied evidence and correct species/units.
Explain the relevant mechanism or relationship.
Show intermediate working or a labeled model.
State an assumption, limitation or useful next test.

Session 4 · Electron Transitions & Emission Spectra — apply and explain

Use the linked chapter reading, unit explanations, figures and notebook.

Your task

Prepare the assigned explanation and identify the question.
Trace a model or graph, labeling its species and units.
Attempt the assigned reasoning and calculation before opening guidance.
Compare with criteria and retain an explained correction.

Hint and response guidance

Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.

The first photon has 3.0 eV, or about 4.81×10⁻¹⁹ J, giving λ≈4.14×10⁻⁷ m =414 nm. A later allowed 1.5-to-0 transition could emit a 1.5 eV photon; the selected model does not supply transition probabilities.

Use the supplied evidence and correct species/units.
Explain the relevant mechanism or relationship.
Show intermediate working or a labeled model.
State an assumption, limitation or useful next test.

Session 5 · Spectrum Evidence and Identification — plan and examine records

Use the linked chapter reading, unit explanations, figures and notebook.

Your task

Read the full investigation. Define question, boundary, variables, units and route. Use a suitable supervised method or the complete supplied-data route, preserving all records and a first model.

Prepare the assigned explanation and identify the question.
Trace a model or graph, labeling its species and units.
Attempt the assigned reasoning and calculation before opening guidance.
Compare with criteria and retain an explained correction.

Hint and response guidance

Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.

Unknown matchesA within 2 nm at every supplied line.450 nm has highest photon energy and 650 nm lowest. Identity is supported within this simplified reference set, not proven among all possible elements or mixtures. 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.

Use the supplied evidence and correct species/units.
Explain the relevant mechanism or relationship.
Show intermediate working or a labeled model.
State an assumption, limitation or useful next test.

Submit this week

Labeled first/revised models and intermediate calculations.
Assigned practice and assessed attempts with explained corrections.
Investigation record/report when assigned, identifying supplied versus collected data.

Parent / teacher weekly conference

Use actual written work to adjust support. Do not count a copied solution as independent mastery. Extend or redistribute time where needed; home-study records do not certify supervised or mandated laboratory requirements.

Can each relevant symbol and unit be explained?
Does the calculation conserve the appropriate quantities?
Can the learner solve a changed case and explain an assumption?

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