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 change that results in the formation of new chemical substances. It involves a chemical reaction and includes processes like burning, rusting, and digestion.

Front

What happens to a chocolate bar when it melts?

Back

Melting a chocolate bar is an example of a physical change because it changes from solid to liquid without changing its chemical structure.

Front

What causes iron to rust?

Back

Iron rusts due to a chemical reaction with oxygen and moisture in the environment, resulting in the formation of iron oxide.

Front

What are some indicators of a chemical change?

Back

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

Front

What is an example of a physical change?

Back

Cutting a tree limb into logs is a physical change because it alters the size and shape but not the chemical composition of the wood.

Front

What is an example of a chemical change?

Back

Burning wood in a fireplace is a chemical change because it transforms the wood into ash, smoke, and gases.

Front

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

Back

A physical change does not alter the chemical composition of a substance, while a chemical change results in the formation of new substances.

Front

What is evidence of a physical change?

Back

Evidence of a physical change includes changes in shape, size, or state of matter, such as ice melting into water.

Front

What is evidence of a chemical change?

Back

Evidence of a chemical change includes the production of gas, a change in color, or the formation of a precipitate.