Activities

1. Define “physical change” and “chemical change.” Give an example for each.
   
   
2. Some chemical changes occur quickly and others take a longer amount of time. Which chemical change will occur first, second, and third?
   
   
   1. Rust occurring on a car.
   2. An avocado oxidizing, or turning brown.
   3. Drink mix dissolving in to water.
      
      
3. Physical change can also vary in length of time. Which physical change will most likely occur first, second and third?

1. Tearing a piece of paper.
2. Chocolate melting in your hand.
3. Boiling water.

4. Create an experiment book with 2 experiments showing Physical Changes, and 2 experiments showing Chemical Changes.

5. Have a debate with your classmates on the topic: Which type of change occurs more- Chemical or Physical?
   
   
6. Pretend you are a household product. For example you could be an iron, a fork, a refrigerator, a toothbrush, stove, etc. How does this item help with chemical or physical change? Write a short paragraph explaining your thoughts. Then compare and share with the people at your table.

Answer Key/Rubric

1. Acceptable responses might include, but are not limited to:

• Physical change can be from one phase to another, for example ice melting to liquid water. No new chemicals or substances are formed in a physical change
• Chemical change is when a new chemical or substance is formed; bonds of atoms are either made or broken. For example, when salt is dissolved into water, and rust.

2. Answers as follows:
   
   
   1. Rust occurring on a car. THIRD- occurs slowest of the examples
   2. An avocado oxidizing, or turning brown. SECOND
   3. Drink mix dissolving in to water. FIRST- occurs fastest of the examples
      
      
3. Answers as follows:
   
   
   1. Tearing a piece of paper. FIRST- occurs fastest of the examples
   2. Chocolate melting in your hand. - SECOND
   3. Boiling water. THIRD – occurs slowest of the examples

4. Acceptable responses might include, but are not limited to:

• Chemical changes: observing rust on a penny using vinegar and salt, dissolving a powder into a liquid (i.e. baking soda and vinegar; salt and water), burning an object to show combustion, mentos and soda
• Physical changes: changing the phase of matter (s à l, l à g, l à s), boiling water, breaking an object into smaller pieces

Suggested Rubric: This rubric may be used to assess a student’s overall mastery of the standard or eligible content:

5. Acceptable responses might include, but are not limited to:

• Physical changes may occur more because it can be something as quick as breaking, or ripping a piece of paper. Physical changes only change the object without making an entirely new substance.
• Chemical changes occur more often because they happen without any human interaction, for example rust occurring on a car. We may not notice chemical changes because they can take a long time to occur. Also, much of the way we prepare food involves chemical changes.
• Both chemical and physical changes are a major part of our daily lives.

6. Acceptable responses might include, but are not limited to:

• A fork can break down food into smaller objects, physical change.
• An iron can physically change a cloth to be less wrinkled, but it can also melt object too (chemical change).
• A refrigerator can be part of a physical change for example making something like gelatin into a solid, but it can also have areas of rust.
• A toothbrush would mainly occur with physical changes by breaking down plaque on teeth. Chemically, toothpaste would create a reaction mixing baking soda with substances.
• A stove would be involved in changing the phase of matter of water, or melting butter or chocolate. It can also be part of chemical changes when ingredients are mixed together to make a new substance.