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Finding the Density of Earth

Time Frame:
1 class period that runs 60 minutes.

Group Size:
Small Groups


Students will use rock samples to determine the density of Earth.

Main Curriculum Tie:
SEEd - Grade 7 (2017)
Strand 7.2: Changes to Earth over time 7.2.4

Develop and use a scale model of the matter in Earth’s interior to demonstrate how differences in density and chemical composition (silicon, oxygen, iron, and magnesium) cause the formation of the crust, mantle, and core.


  • rocks of different densities such as basalt, granite, slate, iron (can be a nail, utensil or tool).
  • triple-beam balance
  • water
  • graduated cylinder
  • Student worksheet


Instructional Procedures:

  1. Ask students if it is possible to measure the density of an object as large as Earth. Give them a chance to talk to one another for a brief time and see if they can answer it. They may think about finding mass and volume but those are difficult measurements and calculations. They may decide that samples from various places in Earth could be used to represent the whole.
  2. Show them the rocks you have gathered and read the introduction.
  3. Indicate the location of materials and read the procedures with students.
  4. Allow time to work.
  5. Ask students to post their results on the board for Earths density and see how close they come to 5.5 g/cc.

Lesson Design by Jordan School District Teachers and Staff.

Utah LessonPlans

Created Date :
Oct 01 2014 13:42 PM