Author Question: What evidence tells us that early Earth contained radioactive isotopes that are no longer present? ... (Read 40 times)

crobinson2013

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What evidence tells us that early Earth contained radioactive isotopes that are no longer present?
 
  What will be an ideal response?

Question 2

Has the innermost part of Earth's core always been solid and constant in size?
 
  What will be an ideal response?



srodz

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Answer to Question 1

The daughter products of these isotopes are present in Earth rocks. They are also present in Moon rocks and in meteorites.

Answer to Question 2

No, the Earth's entire core was once molten. The core started to crystallize from the inside outward and continues to crystallize today. The inner core is slowly enlarging.



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