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. Examples include burning, rusting, and cooking.

Front

What happens to the wax of a candle when it burns?

Back

The wax melts (physical change) and the wick burns (chemical change).

Front

How can you tell if a change is physical or chemical?

Back

If the substance changes its form but not its chemical identity, it's a physical change. If it forms a new substance, it's a chemical change.

Front

What are some examples of physical changes?

Back

Examples include melting ice, breaking glass, and dissolving sugar in water.

Front

What are some examples of chemical changes?

Back

Examples include burning wood, rusting iron, and baking a cake.

Front

What is an observation that indicates a physical change?

Back

An observation that indicates a physical change is when the wax of a candle melts.

Front

What is an observation that indicates a chemical change?

Back

An observation that indicates a chemical change is when the candle wick burns with a flickering flame.

Front

How can you determine the physical properties of a substance?

Back

You can determine the physical properties of a substance by using your senses to smell, taste, hear, feel, or see it.

Front

What is the role of heat in physical and chemical changes?

Back

Heat can cause physical changes (like melting) and can also drive chemical changes (like burning).