Question

1. place the following layers in order from most dense to least dense: asthenosphere, mantle, inner core, lithosphere, outer core, crust
2. which of the following are sources of heat in earth’s interior, either currently or early earth? (hint: there are 3 correct answers)

a) solar heating
b) gravity (pulling objects in for collisions forming early earth, contraction of molecu
c) radioactive decay of radioactive elements
d) friction (dense material falling towards center of earth, compaction of molecules
e) open flames
9-12. label the image with the correct description of how heat and density changes t
the relationship between depth and heat as well as depth and density.
use the following terms: heat increases, heat decreases, density increases, density

Explanation:

Question 7:

Step1: Recall Earth's layer density

The inner core is the densest (solid, heavy metals), then outer core (liquid, metals), then mantle (semi - solid, silicate - rich), then lithosphere (includes crust and upper mantle, less dense), then asthenosphere (part of mantle, slightly less dense than lithosphere? No, wait, crust is less dense than mantle. Wait, correct order from most dense to least dense: inner core (most dense), outer core, mantle, lithosphere (which includes crust and upper mantle? No, lithosphere is crust + upper mantle rigid part. Wait, crust is the least dense, then lithosphere? No, let's list the layers: inner core (dense), outer core, mantle, asthenosphere (part of mantle, but the crust is less dense than mantle. Wait, the layers given: asthenosphere, mantle, inner core, lithosphere, outer core, crust. Wait, no, the layers to order: asthenosphere, mantle, inner core, lithosphere, outer core, crust. Wait, correct density order: inner core (highest density), outer core, mantle, asthenosphere (part of mantle, but lithosphere includes crust and upper mantle. Wait, crust is less dense than mantle. So the correct order from most dense to least dense: inner core, outer core, mantle, asthenosphere, lithosphere, crust? Wait, no, lithosphere is crust + upper mantle (rigid). The crust is the least dense. So let's re - order:

Inner core (most dense) > outer core > mantle > asthenosphere (part of mantle, but the lithosphere's crust is less dense. Wait, the layers given: inner core, outer core, mantle, asthenosphere, lithosphere, crust. Wait, no, the original layers: asthenosphere, mantle, inner core, lithosphere, outer core, crust. Let's sort by density:

Inner core (dense, solid iron - nickel) > outer core (liquid iron - nickel, less dense than inner core) > mantle (silicate - rich, semi - solid, denser than crust) > asthenosphere (part of mantle, same density range as mantle? No, asthenosphere is more ductile, but density similar to mantle. Then lithosphere (crust + upper mantle, crust is less dense than mantle) > crust (least dense). Wait, but the layers are: asthenosphere, mantle, inner core, lithosphere, outer core, crust. Wait, I think I messed up. Let's list the layers with their density:

1. Inner core: highest density (solid, heavy metals)
2. Outer core: liquid, metals, less dense than inner core but more than mantle
3. Mantle: semi - solid, silicate - rich, denser than crust
4. Asthenosphere: part of mantle, but the lithosphere includes crust and upper mantle. Wait, lithosphere is crust + upper mantle (rigid). The crust is less dense than mantle. So after mantle, the next is asthenosphere? No, lithosphere: crust (less dense) + upper mantle (dense). Wait, the correct order from most dense to least dense: inner core, outer core, mantle, asthenosphere, lithosphere, crust? No, lithosphere has crust which is less dense. Wait, the layers to order: inner core, outer core, mantle, asthenosphere, lithosphere, crust. Wait, no, the given layers: asthenosphere, mantle, inner core, lithosphere, outer core, crust. Let's re - arrange:

Inner core (most dense) > outer core > mantle > asthenosphere (part of mantle, but lithosphere's crust is less dense) > lithosphere (includes crust, so less dense than mantle) > crust (least dense). Wait, no, asthenosphere is below lithosphere. So the correct order: inner core, outer core, mantle, asthenosphere, lithosphere, crust. Wait, but the layers given are: asthenosphere, mantle, inner core, lithosphere, outer core, crust. So we need to sort them:

Inner core (dense) > outer core > mantle > ast…

Step1: Analyze each option

• Option a: Solar heating: In early Earth, solar heating was not a major internal heat source. The internal heat sources are from within Earth.
• Option b: Gravity (pulling objects in for collisions forming early Earth, contraction of molecules): When Earth formed, gravitational accretion (collisions) and contraction (as Earth cooled, but wait, contraction would generate heat? Wait, gravitational attraction caused materials to collide and accrete, and the compression (friction from dense material falling towards center, compaction) and also radioactive decay. Wait, option b: gravity pulling objects for collisions (accretion) and contraction of molecules (compression) would generate heat.
• Option c: Radioactive decay of radioactive elements: Radioactive elements like uranium, thorium, etc., decay and release heat, which is a major internal heat source.
• Option d: Friction (dense material falling towards center of Earth, compaction of molecules): As dense materials sank to the center (differentiation), the friction and compaction generated heat.
• Option e: Open flames: Not a heat source for Earth's interior.

So the correct sources are b, c, d.

Step2: Confirm the correct options

Solar heating (a) is external, open flames (e) are not relevant. So the correct options are b, c, d.

Answer:

inner core, outer core, mantle, asthenosphere, lithosphere, crust

Question 8: