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 mixing, freezing, and boiling.

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 cannot be reversed by physical means.

Front

How can you separate a mixture of sand and iron filings?

Back

You can separate sand from iron filings by using a magnet to pull the iron filings away from the sand.

Front

What indicates a chemical change has occurred?

Back

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

Front

What happens to a bike left out in the rain?

Back

A chemical change will cause the surface of the bike to turn red or rust due to oxidation.

Front

What is an example of a physical change in cooking?

Back

Blending fruits and ice cream to make a smoothie is a physical change because the ingredients are mixed but not chemically altered.

Front

Why can't you change a baked cake back into raw cake batter?

Back

This is because a chemical change has occurred during baking, resulting in new substances that cannot be reverted to their original form.

Front

What is rust?

Back

Rust is a reddish-brown oxide formed when iron reacts with oxygen and moisture in the air, indicating a chemical change.

Front

What is an example of a chemical change?

Back

Baking a cake is an example of a chemical change because the batter transforms into a new substance that cannot be changed back.

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 new substances being formed.