Physical Vs Chemical Change Quick Check Select 1 correct answer per question.

Question

1. Which observation most likely indicates that only a chemical change has taken place?
A. The shape changes.
B. A reaction occurs.
C. States of matter changes.
D. The change cannot be reversed.

2. Use the table of observed changes to answer the question.

Change # Reacts with another substance? Temperature change? Gas, sound, or light produced? New substance formed?
1 yes yes yes yes
2 no yes yes no
3 yes yes yes yes
4 no no no no
Which changes shown in the table are physical changes?
A. 1 and 4
B. 1 and 2
C. 2 and 3
D. 2 and 4

3. Why is it a physical change to freeze water?
A. A temperature change occurs.
B. Only a phase change occurs.
C. Heat is released during the process.
D. The new and original substances are different.

4. Which option is an example of a chemical change?
A. folding paper
B. burning wood
C. chopping vegetables
D. stretching a rubber band

Answer 1

Here are the correct answers for each question:

1. B. A reaction occurs.
   This indicates a chemical change, as a reaction typically involves the formation of new substances.

2. D. 2 and 4
   Change #2 and Change #4 have no new substances formed, indicating they are physical changes.

3. B. Only a phase change occurs.
   Freezing water is a physical change because it only involves a change in state, not a change in the substance itself.

4. B. burning wood
   This is an example of a chemical change because it results in the formation of new substances (like ash and gases) and is not easily reversible.