Structure and Composition of the Earth

Subject area: Science

Grade level: Third

Time needed: 45 minutes to 1 hour

Standard: Earth and Space Science: Understands basic features of the Earth

Materials: overhead projector, Vis-a-Vis markers (several colors), overhead transparency, modeling clay or Play dough (yellow, green, blue, red), toothpicks, index cards (cut into 1 inch squares), tape, construction paper, magic markers, plastic knives

Procedures:

1. Using the overhead projector and a copy of the Earth’s structure (page 4), label the parts of the Earth (crust, mantle, inner core, outer core). Repeat the names several times, and have a few students try to say all the parts as the teacher points to them.
2. Write the vocabulary words on construction paper and tape them to the board for the students to use as a reference.
3. Have a student help pass out medium sized balls of each color modeling clay or Play dough to each student or pair of students.
4. Students will construct a model of the Earth from the inside out. Direct them to make a ball for the inner core, then to put a different color and layer over it for the outer core. The next layer of a different color will be the mantle, and the final color and layer will be the crust.
5. Once the students have all the layers in place, they can cut the Earth in half.
6. Students will write the names of the Earth’s layers on separate index cards, using the words on the board to spell the layers right. Then they will tape the index cards to the toothpicks.
7. Finally, students will place the proper label into the layer that it represents.

Differentiation: Students will have the opportunity to work with a partner if they would like to. The teacher can write the labels for students who have a hard time copying work off of the board.

Technology link: This first part of this activity could also be used with a Smart Board instead of an overhead projector. Students could move the labels around on the graphics on the Smart Board. Students can also look at two websites for pictures and graphics about the layers of the Earth and other geological formations for later studies: www.pbs.org/wnet/savageearth/animations/hellscrust/main.html or www2.nature.nps.gov/geology/tour

Assessment: The teacher will assess students’ work by checking to see if the labels go with the correct layer. The assessment will be done by observation.

Cross Curricular Connection: The teacher could read The Magic School Bus: Inside the Earth to the students as an introduction or follow up to the lesson.