Chemical Changes vs. Physical Changes

You take a piece of paper and fold it into a paper airplane. What kind of change is this?

• Physical Change because it is still paper

• Chemical Change because it is now a functional airplane

Answer explanation

Folding paper into a paper airplane is a physical change because the material remains paper. The structure changes, but no new substance is created, which is characteristic of physical changes.

You leave an ice cube on the table and it melts into a puddle. This is a:

• Physical Change

• Chemical Change

Answer explanation

Melting ice is a physical change because it alters the state of water from solid to liquid without changing its chemical composition.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS3-4

The flour, milk, water, sugar, and egg all turn into a pastry that CANNOT be undone.

The gooey batter turns into a fluffy cake. This is a:

• Physical Change

• Chemical Change

Answer explanation

The transformation of flour, milk, water, sugar, and egg into a pastry is a chemical change because it results in new substances that cannot be reversed, unlike physical changes which can be undone.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

You break your pencil in half by accident. Is this a physical or chemical change?

• Physical Change

• Chemical Change

Answer explanation

Breaking a pencil in half is a physical change because it alters the pencil's shape and size without changing its chemical composition.

When iron (a metal) comes in contact with water for a long period of time, it forms RUST. Since rust is a new substance formed after water comes in contact with iron... this is a...

• Physical Change

• Chemical Reaction

Answer explanation

Rust formation is a result of a chemical reaction between iron and water, leading to a new substance. This process involves the rearrangement of atoms, which is characteristic of a chemical reaction, not a physical change.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

You use your hands to squish a ball of playdough

• Physical Change

• Chemical Change

Answer explanation

Squishing playdough changes its shape but not its chemical composition, making it a physical change. The material remains the same, just altered in form.

A campfire burns a log until it turns into black ash and smoke. This is a:

• Physical Change

• Chemical Change

Answer explanation

The burning of a log results in the formation of ash and smoke, indicating a change in chemical composition. This process is irreversible and involves the release of energy, classifying it as a chemical change.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

You cut an apple into slices... this is a:

• Physical Change

• Chemical Change

Answer explanation

Cutting an apple into slices is a physical change because it alters the shape and size of the apple without changing its chemical composition.

Setting off fireworks by using a match and the powder inside to create an explosion is an example of...

• Physical Change

• Chemical Change

Answer explanation

Setting off fireworks involves a chemical reaction where the powder combusts, producing gas and heat, resulting in an explosion. This process changes the substances involved, making it a chemical change.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which type of change can usually be 'undone' or reversed (like freezing water back into ice or melting ice back into water)?

• Physical Change

• Chemical Change

Answer explanation

A physical change involves alterations in the state or appearance of a substance without changing its chemical composition. Examples include freezing and melting, which can be reversed, making 'Physical Change' the correct answer.