Physical and Chemical Changes

What happens during a physical change?

• New substances form.

• The identity of a substance is changed.

• A chemical reaction occurs.

• A property of a substance changes, but its identity stays the same.

Which of the following is a chemical change?

• water boiling

• paper being cut

• ice melting

• iron rusting

Which is a clue that a chemical change has occurred?

• A beaker becomes warm when you mix two room-temperature liquids in it.

• A liquid forms bubbles when it reaches a high temperature.

• Water changes color when you add food coloring to it.

• A car door feels hot if you touch it on a summer afternoon.

Which of the following would cause a chemical change in a piece of wood?

• hammering a nail into the wood

• burning the wood

• painting the wood

• sawing the piece of wood in half

A physical change is taking place when

• a piece of paper burns

• a piece of fruit rots

• onions are chopped

• a nail rusts