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K12 LibreTexts

15.14: Understanding Earth's History- Challenge 3

  • Page ID
    5916
  • 1. The distinctive patterns of tree rings, ice cores, and ___ can be used to determine the time they were formed.
    varves
    2. The counting of ___ layers is one of the methods of ice core dating.
    dust-snow
    3. ___ analysis yields clues about how changes in the concentration of atmospheric gases have influenced Earth's climate over time.
    Ice core
    4. If two half-lives have passed, ___ percent of the parent isotope remains.
    25
    5. Radioactive decay of an isotope leads to the formation of a ___ product.
    stable daughter
    6. ___ discovered the spontaneous emission of particles that they called "radioactivity."
    Pierre and Marie Curie
    7. When an organism dies, carbon-14 decays to stable nitrogen-14 by releasing a ___.
    beta particle
    8. Carbon dating measures when an organism died because only then does ___.
    carbon-14 decay into nitrogen-14
    9. Carbon-14 dating is used for dating human remains and artifacts because ___.
    carbon-14 has a relatively short half-life and early human fossils and materials often contain carbon
    10. ___ is the most useful technique for dating Earth's matter and coming up with a quantitative age for the planet.
    Radiometric dating
    11. ___ determines the age of an object based on the concentration of a particular radioactive isotope contained within the object.
    Radiometric dating
    12. Earth is ___ years old.
    4.6 billion