Physical and Chemical Changes

Ice melting

• Chemical Change
• Physical Change

Water freezing

• Chemical Change
• Physical Change

Wood burned in a fireplace

• Chemical Change
• Physical Change

Cake batter baked in an oven and becomes a cake

• Chemical Change

• Physical Change

Baking soda (solid) and vinegar (liquid) combine to make carbon dioxide (gas)

• Chemical Change

• Physical Change

Glass bottle that is shattered

• Chemical Change
• Physical Change

Which of the following is NOT an example of a physical change?

• adding sugar to water and watching it dissolve

• copper being bent and flattened into a large sheet of metal

• clothes shrinking after being exposed to high temperatures

• a rusty nail becoming shiny after being exposed to an acid

Stanley left an ice cube on his kitchen counter. An hour later, Stanley observed that the ice cube melted. Which statement best describes this change?

• Ice melting is a physical change because a new substance is created.

• Ice melting is a chemical change because a new substance is created.

• Ice melting is a chemical change because it may be easily reversed.

• Ice melting is a physical change because it may be easily reversed.

When coffee is poured into a cup of ice, the ice begins to melt and mix with the coffee. Which statement best describes this change?

• The ice melting is a chemical change because the water changes form.

• The ice melting is a physical change because the water is changing its state of matter, but not its chemical composition

• The water and coffee mixing is a chemical change because there is a change in the state of matter of the ice

• The water and coffee mixing is a physical change because the mixture forms bubbles.

Which statement best describes why baking a cake is an example of a chemical change?

• The process takes place in an oven, so there is heat involved.

• The process absorbs heat energy, and absorbing heat always results in a chemical change.

• It forms a chemically new substance that is different than the original ingredients, and the process cannot be reversed.

• The process can be easily reversed to get the cake batter back.