Physical and Chemical Changes of Matter

Which process is an example of a physical change?

• Carrots are cut into small pieces and mixed into a salad.

• A peanut butter sandwich is eaten and broken down by enzymes in the stomach.

• Sodium metal and chlorine gas are combined to form sodium chloride, or table salt.

• Sodium metal and water are combined to form a basic compound and a flammable gas.

Which process is an example of a chemical change?

• an iron nail rusting

• bath water cooling while you take a bath

• a piece of metal being heated until it expands

• a glass window breaking when hit with a baseball

There are several differences between chemical and physical changes. Which process is an example of a chemical change?

• steam rising from a boiling pot of soup

• a metal railing rusting in damp weather

• alcohol evaporating from a cotton swab

• a piece of wood shrinking as it dries out

Marco tears a piece of notebook paper into smaller pieces. Tearing paper into pieces is an example of what kind of change?

• a change in mass

• a physical change

• a chemical change

• a change in energy

How are chemical changes different from physical changes?

• Physical changes happen when substances change to form

  new ones, while chemical changes do not form any new substances.

• Chemical changes happen when substances change to form

  new ones, while physical changes do not form any new substances.

• They are the same thing.

• None of these.

Is toasting a piece of bread an example of a physical or chemical change?

• Physical

• Chemical

When the banana, berries, water and hot dog are blended, does a physical or chemical change occur?

• Physical

• Chemical

Is water evaporating an example of a physical or chemical change?

• Physical

• Chemical

In the video, what happens when Dr. Jeff puts the gummy candy into a tube containing oxidizer?

• Nothing.

• the gummy candy became very stretchy and soft. Therefore, this is a physical change.

• the gummy candy bursts into flames producing smoke and carbon (new substances). Therefore, this is a chemical change.

In the video, what happened when Zoe poured carbon dioxide gas onto the candles?

• Nothing.

• The candles went burned more brightly because carbon dioxide gas is lighter than air. When the carbon dioxide rises the air, the candle burns more brightly. This process happens to each candle as the carbon dioxide rises higher and higher.

• The candles went out one by one because carbon dioxide gas is heavier than air. When the carbon dioxide displaces the air, the candle doesn't have enough oxygen, so it goes out. This process happens to each candle as the carbon dioxide sinks lower and lower.