Pre retest Physical and Chemical Changes

Front

What is a chemical change?

Back

A chemical change is a process where substances combine or break apart to form new substances, resulting in a change in chemical composition.

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.

Front

What is a sign that a chemical reaction has occurred?

Back

Formation of a gas, change in color, temperature change, or the formation of a precipitate.

Front

Which of the following is NOT a physical change: crumpling paper, dissolving sugar in water, freezing water, or burning a marshmallow?

Back

Burning a marshmallow is NOT a physical change; it is a chemical change.

Front

What happens to molecules during a chemical change?

Back

Molecules break apart and form new molecules, resulting in the creation of new substances.

Front

What is density?

Back

Density is the mass of a substance divided by its volume, often expressed in grams per cubic centimeter (g/cm³).

Front

How can you identify a physical change?

Back

A physical change can be identified if the substance retains its original properties and no new substances are formed.

Front

What is an example of a chemical change?

Back

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

Front

What is electrolysis?

Back

Electrolysis is a chemical process that uses electricity to break down a compound into its individual elements.

Front

What is the difference between a physical change and a chemical change?

Back

In a physical change, no new substances are formed, while in a chemical change, new substances are created.