Describing Chemical Reactions

Front

What is a physical change?

Back

A physical change is a change in which the substance's physical properties change, but its chemical composition remains the same. Examples include melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. It involves a change in the chemical composition of the substance. Examples include burning, rusting, and digestion.

Front

Why does ice freezing only represent a physical change?

Back

The molecules of water do NOT change; they only slow down and vibrate in position.

Front

What happens during a chemical reaction?

Back

During a chemical reaction, reactants are transformed into products, resulting in the formation of new substances with different properties.

Front

What are reactants in a chemical reaction?

Back

Reactants are the starting substances that undergo a chemical change to form products.

Front

What are products in a chemical reaction?

Back

Products are the substances that are formed as a result of a chemical reaction.

Front

What is an example of a chemical change?

Back

Burning wood in a campfire is a chemical change because it creates new substances, such as ash and smoke.

Front

What is an example of a physical change?

Back

Melting ice is an example of a physical change because it changes from solid to liquid without altering its chemical composition.

Front

How can you identify a chemical change?

Back

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

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.