Physical and 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 melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a process where one or more substances are transformed into new substances with different properties. Examples include rusting, burning, and digestion.

Front

What are some signs that a chemical reaction has occurred?

Back

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

Front

Is melting butter for popcorn a chemical or physical change?

Back

Melting butter for popcorn is a physical change.

Front

True or False: Change in color is always a sign of a physical change.

Back

False. Change in color can indicate a chemical change.

Front

What is an example of a physical change?

Back

Examples of physical changes include crumpling paper, sharpening a pencil, and freezing water.

Front

What is an example of a chemical change?

Back

Examples of chemical changes include rusting iron, burning wood, and baking a cake.

Front

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

Back

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

Front

What happens to the molecules during a physical change?

Back

During a physical change, the arrangement of molecules may change, but their chemical structure remains the same.

Front

What happens to the molecules during a chemical change?

Back

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