Explain a state change without inventing a new substance
See this course’s project requirements
A particle-model notebook explaining states, mixtures, elements, compounds, mass conservation and a physical separation plan from supplied materials.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- Separate measurements from particle explanations.
- Compare solid, liquid and gas models without inflating individual particles.
- Classify all supplied element, compound and mixture drawings.
- Name state transitions while preserving substance identity.
- Balance the supplied closed-system mass stores.
- Choose paper separation methods by recovery goal and complete changed cases.
Review and revise
Use these criteria to check your work and choose what to improve.
- Method: applies the course-specific rules to the supplied cases with visible intermediate work.
- Accuracy: results agree with the stated facts, units, boundaries and independent checks.
- Reasoning: explains why the result follows and identifies a limitation or unresolved question.
- Transfer: completes changed cases and revises the final project when a relevant assumption changes.
Want more background?
The idea in everyday life
Supplied water model in a closed container: ice warms and melts; liquid later produces water vapor; vapor cools and condenses. Particle identity remains H–O–H throughout. This is a desk sequence, not a heating task.
A physical state change changes arrangement and motion while keeping substance identity. Melting moves from solid to liquid; freezing reverses it; vaporization moves liquid to gas; condensation reverses it. Energy transfer can change temperature or support a state transition. Evaporation does not require the entire liquid to boil.
Explain a state change without inventing a new substance — worked practice
A physical state change changes arrangement and motion while keeping substance identity. Melting moves from solid to liquid; freezing reverses it; vaporization moves liquid to gas; condensation reverses it. Energy transfer can change temperature or support a state transition. Evaporation does not require the entire liquid to boil.
Supplied water model in a closed container: ice warms and melts; liquid later produces water vapor; vapor cools and condenses. Particle identity remains H–O–H throughout. This is a desk sequence, not a heating task.
1. 1. Name
Label each supplied transition.
You should see: Melting, vaporization and condensation in the stated order.
2. 2. Preserve
Write what remains the same in every model.
You should see: Water-molecule identity remains H–O–H.
3. 3. Explain
Describe what changes in arrangement or motion.
You should see: Solid positions become liquid rearrangement; vapor particles spread farther apart.
4. 4. Correct
Repair “melting ice makes a new element.”
You should see: The physical state changes; no new element is created by this sequence.
What to finish
A three-transition sequence showing states, energy transfer and unchanged identity.
Watch for this
A physical state change transfers water into its vapor state. Visibility and liquid amount can change without destroying the substance.
How can I tell I understand it?
Identify a changed transition from its starting and ending states.
Quick knowledge check
Answer all 3 questions. Get at least 2 right and the lesson completes automatically.
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Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.
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Source & access notes · checked 2026-10-01
Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.
Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.
Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.
Source & access notes · checked 2026-10-01
Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.
Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.
Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.
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