Key Idea: The earth's plates sit on a hot, slightly softened layer of the earth.
Students are expected to know that:
- Rocks can be solid, liquid, or in a slightly softened form.
- The layer beneath earth’s plates is made of rock that is hotter and less rigid than the plates.
- The layer beneath earth’s plates is just slightly softened (just as wax and metal become softened when heated but not yet melted).
- The layer beneath earth’s plates moves very slowly and in different directions in different locations around the earth.
Boundaries:
- Students are not expected to know that the layer beneath the plates is called the asthenosphere, or that this layer has the properties it does because of pressure being applied to it in addition to the high temperature inside the earth.
- Students are not expected to know that the asthenosphere is not uniform and that liquid magma flows through parts of the asthenosphere.
- Students are not expected to know how the earth behaves beneath this layer.
| Item ID Number |
Knowledge Being Assessed | Grades 6–8 |
Grades 9–12 |
Select This Item for My Item Bank |
|---|---|---|---|---|
47% |
53% |
|
||
27% |
31% |
|
||
The layer beneath earth's plates mostly consists of slightly softened rock. | 17% |
13% |
|
Misconception |
Student Misconception |
Grades |
Grades |
|---|---|---|---|
36% |
32% | ||
The layer beneath earth's plates mostly consists of liquid rock material (AAAS Project 2061, n.d.). | 30% |
38% | |
The layer beneath earth's plates mostly consists of solid rock material (AAAS Project 2061, n.d.). | 32% |
30% | |
The entire layer beneath the earth's plates moves in one direction (AAAS Project 2061, n.d.). | 23% |
19% | |
21% |
18% | ||
The layer below the earth's plates does not move (AAAS Project 2061, n.d.). | 16% |
12% | |
The layer beneath the earth's plates moves very rapidly (AAAS Project 2061, n.d.). | 14% |
15% |
Frequency of selecting a misconception was calculated by dividing the total number of times a misconception was chosen by the number of times it could have been chosen, averaged over the number of students answering the questions within this particular idea.
No NGSS statements are associated with this idea in the selected project.