Matter can be described by the properties that distinguish one substance from another. Some properties can be observed without changing a substance’s chemical identity, while others describe how it can react and become a different substance.
A physical property is a characteristic of matter that can be observed or measured without changing its chemical composition. Examples include density, color, hardness, melting point, boiling point, and electrical conductivity. Some, such as color and density, can be observed without changing the substance’s state. Others, such as the melting point of iron, are observed as the substance undergoes a physical change.
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What is a physical property?
A characteristic that can be observed or measured without changing a substance’s chemical composition, such as density, color, or melting point.
How can you recognize a physical change?
A physical change alters matter’s state, form, or physical properties, but the chemical identities of the substances remain unchanged.
What does a chemical property describe?
It describes a substance’s ability or inability to change into different kinds of matter, as with flammability, acidity, or reactivity.
What defines a chemical change?
A chemical change produces one or more kinds of matter with different chemical identities from the matter present before the change.
How do extensive and intensive properties differ?
An extensive property depends on the amount of matter, as mass and volume do. An intensive property, such as temperature, does not depend on the sample amount.
Quiz questions
What is a physical property?Answer: A characteristic measurable without altering chemical composition.
Which example is a physical change?Answer: Steam condensing into liquid water.
What makes rusting a chemical change?Answer: Rust has a different chemical identity from the materials present before rusting.
Which is a chemical property of a substance?Answer: Flammability
A solid is ground into powder. How should the grinding itself be classified?Answer: A physical change, because it changes form without changing chemical composition.
Based on Chemistry 2e by Paul Flowers, Klaus Theopold, Richard Langley, William R. Robinson, PhD (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.