Physical change and chemical change
A change of phase need not change chemical identity.
Key knowledge
A physical change alters a material's state or physical arrangement while retaining its chemical identity. A chemical change transforms chemical substances into different substances. Melting is a physical change; a chemical reaction changes composition. A visible color change, bubbling or temperature change alone does not establish which substances changed.
Conditions and scope
- Classify the actual process and species, not merely its appearance.
- Dissolution may disperse existing species, produce ions by reaction, or accompany other reactions; it is not universally one kind of change.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Paul Flowers, Klaus Theopold, Richard Langley and William R. Robinson · OpenStax/Rice University2 sources
- Chemistry 2e (2019), §1.3 Physical and chemical propertiesPaul Flowers, Klaus Theopold, Richard Langley and William R. Robinson · OpenStax/Rice UniversityTextbook chapter
- Chemistry 2e (2019), §11.2 ElectrolytesPaul Flowers, Klaus Theopold, Richard Langley and William R. Robinson · OpenStax/Rice UniversityTextbook chapter
Evidence and review
Inspected §1.3 physical/chemical change definitions and examples, and §11.2 ionic dissociation versus covalent-solute ion formation. No universal classification of every dissolution process is inferred.
2026-10-10 · Independent Mathematics and Information editor (/root/core_math_information). Independent AI editorial review of this entry's statements, equations, applicability conditions and source coverage. Source checks apply to these claims within their stated limits.
Entry details
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- foundation-chem-physical-chemical-change
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- foundations-refresh.1
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