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 changes the composition of the original substance. Examples include burning, rusting, and cooking.

Front

Is mowing the lawn a physical or chemical change?

Back

Mowing the lawn is a physical change because it alters the appearance of the grass without changing its chemical structure.

Front

What happens during a chemical change?

Back

During a chemical change, the atoms in the reactants rearrange to form new substances with different properties.

Front

Is fireworks exploding a physical or chemical change?

Back

Fireworks exploding is a chemical change because it involves a chemical reaction that produces new substances and energy.

Front

Is frying an egg a physical or chemical change?

Back

Frying an egg is a chemical change because it changes the structure of the proteins in the egg, resulting in a new substance.

Front

Is melting ice cream a physical or chemical change?

Back

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

Front

What is rusting?

Back

Rusting is a chemical change that occurs when iron reacts with oxygen and moisture in the air, forming iron oxide (rust).

Front

Can physical changes be reversed?

Back

Many physical changes can be reversed, such as freezing and melting, but some may not be easily reversible.

Front

Can chemical changes be reversed?

Back

Chemical changes are often not easily reversible, as they result in the formation of new substances.