Unit 7: Matter and Solutions
Name:
Aim 40: How are changes in Energy and Matter related?
I.
Date: _________________________
Conservation of Mass
Read pg. 25 in your workbook and answer the following questions:
1. True or False: When water evaporates, it disappears.
Explain why:
2. Define the Law of Conservation of Mass:
3. Circle the correct answer in parenthesis: During a chemical change, atoms are ( lost / gained / rearranged )
II.

Answer the “conservation of mass” question on the right side of the page”

Complete the boxes in the diagram in the middle of the page

Answer the assess your understanding questions at the bottom of the page
Chemical Reactions
During a chemical reaction, two or more substances called reactants, interact to create different substances,
called products. Chemical reactions involve changes in properties and changes in energy that you can often
observe. During a chemical reaction, bonds that hold atoms together break so they can form new bonds. When
bonds are broken, energy is needed. When bonds are formed, energy is released.
1. This is the equation for
which is when
2. What are the reactants (substances you START with)?
3. What are the products (substances you END with)?
4. Indicate how many atoms of each element you start and end with by completing the chart below
Element
# Atoms during reaction
# Atoms after reaction
5. Did you begin and end with the same amount of atoms for each element?
6. Did you begin and end with the same substances?
7. Are atoms created or destroyed during a chemical reaction?
8. What was the cause of this chemical reaction that caused the atoms to be rearranged?
III.
How are changes in Energy and Matter Related?
Read pg. 26-27 and answer the following questions:
1. Define Energy:
2. Every chemical and physical change in matter includes a change in
3. True or False: Bending a paperclip requires energy, but ice changing to liquid does not
Explain your answer:
4. Similar to how matter can never be destroyed, what else cannot be created or destroyed – only transformed?
5. Define thermal energy:
6. Compare and contrast exothermic & endothermic change in the venn diagram below. Include the following:
a. Definition of the term
b. Example of the term
c. Two similarities between the two terms
EXOTHERMIC CHANGE
ENDOTHERMIC CHANGE
a. An exothermic change is ….
a. An endothermic change is ….
c.
b. An example of an exothermic
change is ….
b. An example of an endothermic
change is ….
7. The energy stored in the chemical bonds between atoms is a form of energy called ____________________.
This type of energy naturally flows from warmer to cooler matter.
a. Name three places this type of energy is stored:
b. How do animals (like you! And bears!) gain chemical energy?
c. Describe the energy transformation that occurs when you ride your bike:
COMPLETE THE REVIEW QUESTIONS!  Pg. 30-31 (all), pg. 32 #15-18, pg. 33