Unit 4- Changing Matter

Front

What is a chemical change?

Back

A process where a substance transforms into a different substance with new properties, often accompanied by color change, gas production, or heat release.

Front

What is a physical change?

Back

A change that affects one or more physical properties of a substance without altering its chemical composition, such as melting or boiling.

Front

What happens to the mass of reactants and products in a chemical reaction?

Back

The mass of reactants is equal to the mass of products, according to the Law of Conservation of Mass.

Front

How does temperature affect the rate of a chemical reaction?

Back

Increasing temperature generally increases the rate of a chemical reaction.

Front

What is the Law of Conservation of Mass?

Back

Mass is conserved and remains constant during physical and chemical changes; it is neither created nor destroyed.

Front

What is an example of a physical change?

Back

Melting ice into water is a physical change because the substance remains H2O.

Front

What is an example of a chemical change?

Back

Burning wood is a chemical change because it produces ash, smoke, and gases, changing the original substance.

Front

What indicates a chemical change has occurred?

Back

Indicators include color change, gas production, temperature change, and formation of a precipitate.

Front

What is a reversible change?

Back

A change that can be undone, such as freezing and melting water.

Front

What is an irreversible change?

Back

A change that cannot be undone, such as cooking an egg.