You are my density!
3200-02 Students will compare and contrast the structure of Earths
crust and interior.
OBJECTIVE 3200-0201 Construct and defend a model of Earth's crust
Explain how density affects the organization
of materials that make up Earth's crust and interior.
Intended Learning Outcomes:
1a. Make observations and measurements.
1d. Make predictions based on observations.
2g. Construct models to describe natural phenomena.
5c. Understand science concepts and principles
The students should be familiar with the layers of
the earth and how the density of the earth' s layers is thought to increase
- 4 large containers - Large soda bottles, milk
jugs, glassware, etc
- Food coloring (yellow, blue, red, and green)
- Salt or Sugar
- 1 spoon for each group
- 4 small containers for each group - test tubes,
beakers, or clear plastic cups
- 1 small container for each group to be used for
waste after each trial
- Clear straw
Fill 4 large containers with water. Color each container
of water a different color. The greater the color intensity the better.
- Each group of students will receive a straw, a
spoon, a ruler, and a total of five small containers. Four of the containers
to be filled with colored solution and one to be used as waste.
- Using the ruler, the students will mark the straw
from the bottom up every centimeter for about 4 cm.
- The students will fill four small containers 2/3
full with a different color in each container.
Instruct students to :
- add one level spoonful of salt or sugar to the
- add two level spoonfuls of salt or sugar to the
- add three level spoonfuls of salt or sugar to
the red solution
- add nothing to the green solution
Stir each container well to make a solution
- Place the straw into the one of the colored solutions
to a depth of 1 cm. Seal the top with your finger and then remove the
- Keep your finger on the straw and put it into
a different solution to a depth of 2 cm. Take your finger off the straw
while the straw is in the solution and then seal the straw by replacing
your finger on the end of the straw. Lift the straw out of the solution.
Record your observations either as a drawing or on a chart. Empty the
straw into the waste container.
- Repeat step 5 using different solutions. Record
your observations. How does the solution form layers? Can you create
three layers? Can you make four layers?
- Compare your results. Draw a picture of the solutions
with the greatest density on the bottom and the least density on top.
Now draw a picture of the interior of the earth. Using the same colors
from the solutions to match the layers of the earth.
- Now write an essay comparing the activity to the
layers of the earth
Print this page in Adobe Acrobat format.
Visit the Utah
State 7th Grade Integrated Science Core Curriculum Page.
by: Glen Westbroek
Science Home Page
| Curriculum Home Page | Core
Home Page | USOE Home Page
Copyright © by the Utah State Office of Education