Physical or Chemical Change/Phases

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What is a physical change?

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A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include changes in state (like melting or boiling), shape, or size.

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What is a chemical change?

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A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and the breaking and forming of bonds. Examples include rusting of iron and burning of wood.

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What happens to the temperature of water during a phase change?

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The temperature of water remains constant during a phase change, even when heat is added. This is because the energy is used to change the state of the water rather than increase its temperature.

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What is an example of a physical change involving water?

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Boiling water is an example of a physical change, as it changes from liquid to gas without altering its chemical composition.

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What is an example of a chemical change involving water?

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The decomposition of water (H2O) into hydrogen (H2) and oxygen (O2) is a chemical change, as it results in the formation of new substances.

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What occurs when salt is dissolved in water?

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When salt is dissolved in water, it undergoes a physical change. The salt dissociates into its ions, but no new substances are formed.

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What is the effect of adding heat to a solid?

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Adding heat to a solid can cause it to melt and change into a liquid, which is a physical change.

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What is the effect of removing heat from a liquid?

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Removing heat from a liquid can cause it to freeze and change into a solid, which is a physical change.

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What is the term for a change from solid to liquid?

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Melting.

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What is the term for a change from liquid to gas?

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Vaporization.