The Earth is made up of layers rather than a solid mass. According to Larry Braile of Purdue University, the three main layers are the inner core in the center, the outer core outside the inner core, and the mantle, which is beyond the outer core. Beyond that is the crust, the surface where the Earth's inhabitants live. Make a 3D model of the Earth's layers without using Styrofoam by using homemade play dough. You can control the colors, and it is less expensive than store-bought dough.
Measure 4 cups water, 4 tablespoons vegetable oil, 2 cups salt, 4 tablespoons cream of tartar and 4 cups flour into a large mixing bowl. Mix together well with a spoon.
Measure out 1/2 cup of the flour mixture and place it in a saucepan. Add 1 drop of yellow food coloring to create the play dough for the inner core. Mix with a spoon to check the color. Add another drop of yellow if necessary to achieve an intense shade of yellow.
Heat the saucepan on the stove on medium. Stir the mixture as it heats. Once it starts to become thick and turn shiny, remove the pan from the stove. Turn out the yellow inner core play dough into a bowl.
Add 3/4 cup of the flour mixture to the saucepan. Drop 1 drop of red and 2 drops of yellow food coloring into the mixture to make orange play dough for the outer core. Stir well and heat on the stove at medium. Remove the saucepan from the stove once the mixture becomes thick and shiny. Place the orange play dough into another bowl.
Add 1 cup of the flour mixture into the saucepan. Add 2 drops of red food coloring and stir to mix well. Add another drop of food coloring if necessary to make the dough bright red for the mantle. Heat the red mantle play dough on the stove. Once it is thick and shiny, place it in a bowl.
Measure 3/4 cup of flour mixture into the saucepan and add 3 drops of blue food coloring. This is for the oceans on the Earth's crust. Stir well and heat it until thick and shiny. Remove the blue play dough to another bowl.
Add the rest of the flour mixture into the saucepan. Drop 1 drop of blue and 2 drops of yellow food coloring into the mixture to create green for Earth's landforms. Stir well and heat. Once it is thick and shiny, place it in a bowl.
Roll a ball with the yellow inner core play dough. Wrap the inner core with the orange outer core play dough. Be sure the model is spherical.
Add the red mantle dough over the exterior of the orange dough. Smooth it with your fingers. Be sure to maintain the model's spherical shape.
Cover the entire ball with blue play dough for the crust. Press on pieces of green play dough to represent Earth's landforms. Use a globe as a reference for the shapes of the landforms.
Slice the entire Earth model in half with a sharp knife to expose the layers. The center is the inner core, the orange area is the outer core, the red is the mantle and the exterior is the crust.
You can vary the colors used for the model.
This craft creates a model that is approximately 8 inches wide. Use more or less play dough to change the size of the project. Be sure to maintain the proportions between layers.
Add the food coloring to the flour mixture before heating it or the color will bleed onto your hands.
Adults need to supervise the heating and slicing of the play dough.