Els q4

1. Nebula collapses because of gravitational force, and contracts as it spins more rapidly.
4. Hypothesis is about angular momentum of the sun.
10. The planets should have elements most vital to life.
12. Presence of heavier elements (metals) that the star contains.
13. The planets were formed from the substance that was torn out
14. Separates the upper mantle from Earth’s crust.
17. Solar System was formed into bodies with nearly circular orbits

2. Separating the outer and inner core is a seismic boundary sometimes referred to as.
3. Detected between the lower mantle and the outer core as observed by changes in the seismic waves.
5. The planets were formed by the collision of the sun with a giant
6. of the whirlpool-like motion in the pre-solar materials.
7. Outermost layer of the earth.
8. A habitable zone is a shell-shape region of space surrounding a star where the temperature is just right (not too hot nor too cold) that it could maintain liquid water on its surface.
9. Must be atleast 3 Ga old to give life an ample time to evolve.
11. Mass must be large enough to retain the atmosphere and have a molten core that serves as a heat engine driving the geological processes.
15. the sun.
16. Takes up the largest portion of Earth.