Chemical and Physical Changes in Matter

Front

What is a chemical change?

Back

A chemical change is a process that causes the identity of a substance to change, resulting in the formation of one or more new substances.

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What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What are signs of a chemical reaction?

Back

Signs of a chemical reaction include color change, gas production (bubbles), temperature change, and the formation of a precipitate.

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means.

Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically bond together in fixed proportions.

Front

What is a homogeneous mixture?

Back

A homogeneous mixture is a mixture in which the composition is uniform throughout, such as saltwater.

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What is a heterogeneous mixture?

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A heterogeneous mixture is a mixture in which the composition is not uniform, such as a salad.

Front

What happens when sugar is burned?

Back

When sugar is burned, it undergoes a chemical change, producing carbon dioxide, water, and other compounds, along with a change in color and odor.

Front

Is melting butter a chemical or physical change?

Back

Melting butter is a physical change because it changes from solid to liquid without altering its chemical composition.

Front

What is the law of conservation of mass?

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The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; it is conserved.