PHYSICAL AND CHEMICAL CHANGES and atom counting

Front

What is a physical change?

Back

A physical change is a change in which the substance retains its original properties and composition, such as melting, freezing, or dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new substances with different properties, such as rusting, burning, or cooking.

Front

Give an example of a physical change.

Back

Melting of ice-cream.

Front

Give an example of a chemical change.

Back

A penny tarnishing.

Front

True or False: In a physical change, the substance formed has different properties than the original substance.

Back

False.

Front

What is the correct formula for three hydrogen (H), one sulfur (S), and four oxygen (O)?

Back

H₃SO₄.

Front

What evidence indicates a chemical reaction has occurred?

Back

The formation of a new substance.

Front

What happens to the properties of a substance during a physical change?

Back

The properties remain the same.

Front

What happens to the properties of a substance during a chemical change?

Back

The properties change, resulting in new substances.

Front

List one sign that a chemical change has occurred.

Back

Color change, gas production, temperature change, or formation of a precipitate.