Physical vs. Chemical Changes

Front

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. Examples include changes in state (like melting or freezing), shape, or size.

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 chemical reaction and the rearrangement of atoms. Examples include rusting, burning, and souring of milk.

Front

Which of the following is NOT an example of a physical change: crumpled paper, pencil sharpening, shrunken clothing, sour milk?

Back

Sour milk is NOT an example of a physical change; it is a chemical change.

Front

What happens during a chemical change?

Back

During a chemical change, the bonds between atoms are broken and new bonds are formed, resulting in the creation of new substances.

Front

Is melting butter for popcorn a chemical or physical change?

Back

Melting butter for popcorn is a physical change.

Front

What is an indicator of a chemical change?

Back

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

Front

Can physical changes be reversed?

Back

Many physical changes can be reversed, such as freezing and melting, but some may not be easily reversible.

Front

What is an example of a chemical change?

Back

An example of a chemical change is an explosion, which involves a rapid chemical reaction.

Front

What does it mean if a substance cannot return to its original state?

Back

If a substance cannot return to its original state, it indicates a chemical change has occurred, as new substances have formed.

Front

What happens to a copper penny over time?

Back

A copper penny can turn greenish over time due to a chemical change called oxidation.