Earth Formation Puzzle

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Across
  1. 1. ________________ decay releases heat, and early in the planet’s history
  2. 6. Materials that are _______________ in density became part of the mantle
  3. 8. that asteroid impacts were _____________ in the early solar system.
  4. 9. Earth came together (accreted) from the cloud of dust and _____________
  5. 11. Earth was not always the _____________ and habitable planet it is today.
  6. 12. The first crust was probably _______________, like the oceanic crust is today
Down
  1. 1. The _________________ of basaltic crust was so effective that no remnants of it are found today.
  2. 2. Earth _____________ at the same time as the other planets
  3. 3. When Earth first came together it was really ________
  4. 4. As Earth’s internal _______________ grew, its temperature also rose.
  5. 5. When Earth was entirely ________________, gravity drew denser elements to the center
  6. 7. release of ____________ amounts of heat
  7. 10. _________________ caused small bodies of rock and metal orbiting the proto-Sun to smash together to create larger bodies