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LMS Ch 8.2 DR
Determining Absolute Age Directed Reading
Question | Answer |
---|---|
A method scientists use to determine absoulute age is?? | Using geologic processes that can be observed and measured over time. |
Another method of determining absolute age is?? | Measuring the chemical composition of certain materials in rock. |
Which geologic feature can be given an absolute age using rates of erosion?? | Niagara Falls. |
Rate of erosion is not a dependable way of determining the absolute age of the Grand Canyon because?? | The Grand Canyon formed over millions of years, and rates of erosion may have varied greatly. |
Small amounts of what type of materials in rocks can act as natural clocks?? | Radioactive Materials. |
Atoms of the same element that have different numbers of neutrons are called?? | Isotopes. |
Radioactive Isotopes emit particles and energy?? | At a constant rate regardless of surrounding conditions. |
When radioactive isotopes decay?? | Particles are emitted, but no energy is released. |
In what way is the natural breakdown of radioactive elements most useful to scientists?? | It can accurately measure the absolute age of rocks. |
The method of using radioactive decay to measure the absolute age of rocks is called?? | Radiometric Dating. |
What happens when an atom emits particles and energy?? | The atom changes into a different isotope of the same element or into an isotope of a different element. |
The original radioactive isotope in a rock is called?? | The parent isotope. |
The method used to determine the age of organic remains included in rock layers is called?? | Carbon-14 dating, or radiocarbon dating. |
What does most CO2 in the atmosphere contain?? | Small amounts of nonradioactive carbon-12 and large amounts of the radioactive isotope carbon-14. |