Question

question 1
which process allowed earths surface to cool and form a crust?
heat loss through radiation and volcanic activity
impact from comets
plate tectonics breaking the crust
question 2
which sequence best shows the correct order of events in earths early history?
formation → heavy bombardment → solid crust forms → oldest rocks form
heavy bombardment → earth forms → solid crust forms → oldest rocks form
earth forms → oldest rocks form → heavy bombardment → solid crust forms

Explanation:

Question 1

To determine the process that allowed Earth’s surface to cool and form a crust, we analyze each option:

• "Heat loss through radiation and volcanic activity": Earth’s early surface cooled as heat was lost via radiation (emitting heat into space) and volcanic activity helped release heat and gases, allowing the surface to solidify into a crust.
• "Impact from comets": Comet impacts would add heat and materials, not cool the surface to form a crust.
• "Plate tectonics breaking the crust": Plate tectonics occur after the crust forms, so this can’t be the process that formed the crust.

To find the correct sequence of Earth’s early history:

1. First, Earth forms (accretion of materials).
2. Then, heavy bombardment occurs (asteroids/comets hit the young Earth).
3. After bombardment, the surface cools enough for a solid crust to form.
4. Finally, the oldest rocks form on this solid crust.

Analyzing the options:

• "Formation → Heavy bombardment → Solid crust forms → Oldest rocks form": Matches the logical order (Earth forms, gets bombarded, cools to form crust, then rocks form on the crust).
• "Heavy bombardment → Earth forms...": Earth must form before bombardment, so this is incorrect.
• "Earth forms → Oldest rocks form...": Rocks can’t form before the crust (which forms after bombardment), so this is incorrect.

Answer:

A. Heat loss through radiation and volcanic activity

Question 2