Question

Which processes produced heat that contributed to the formation of Earth’s different layers? Check all that apply.

collision of materials
compaction of materials
cooling of low-density metals
radioactive decay
sinking of high-density metals

Answer 1

The processes that produced heat contributing to the formation of Earth’s different layers include the following:

1. **Collision of materials** - As the early Earth formed, the collision of planetesimals generated significant heat.
2. **Compaction of materials** - The gravitational compression of materials helped to generate heat as the Earth accumulated mass.
3. **Radioactive decay** - The decay of radioactive isotopes within the Earth continues to produce heat, contributing to thermal energy.
4. **Sinking of high-density metals** - As denser materials sank toward the center, this process also generated heat due to friction and compression.

The process **cooling of low-density metals** would not contribute heat to the formation of the layers, as cooling typically results in heat loss rather than heat generation.

Thus, the applicable processes are:
- Collision of materials
- Compaction of materials
- Radioactive decay
- Sinking of high-density metals