Question

1) Summarize the basic principles used in relative dating.

2) How is radiometric dating like an hourglass and how is it different? Why are so many different isotopes used?

3)What must be taken into account regarding daughter isotopes when using any radiometric tool, and how does the Potassium-Argon system overcome that challenge?

4) How does carbon-14 dating work, for what time span is it useful, and how has it been verified?

5) What kinds of information can be learned from ice cores and how far into the past do they allow us to look?

6) Differentiate between sedimentary, igneous, and metamorphic rock, and explain which types of rocks fossils form in, what types of rocks can we radiometrically date, and how fossils are dated.

Its all one question so sorry there are 6 parts!

Answer 1

1.

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The basic principles used in relative dating was to determine the formation of rocks and sequential order of series of events when it occurred and reading of the order method is known as stratigraphy. This indicated that upper part of the rock is younger than the lower part. Therefore, scientists are able to make a complete geologic history by filling in the ‘eroded rock layers’.

2.

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Radiometric dating like an hourglass by how the individual sand grain is radioactive atoms. It’s difficult to tell when an individual grain will fall but it can be able to tell when they hit the base. Moreover, all the grain of sand is at the base without keeping no longer time.   

The radiometric dating is different from hourglass by time which is constant when the sand grains go to the base. Radiometric dating requires half of the number of radioactive atoms then half of the remaining and this would be an exponential curve on a graph and can’t change the rate

Some isotopes are long half-lives and some are short half-lives. Long half-lives isotopes are used to correlate with ancient events while short half-lives isotopes are used to correlate with shorter intervals and they have more accuracy. That’s why different isotopes are used for different purpose.

3)

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It is difficult to assume that there weren’t any daughter isotopes, to begin with when determining the ratio between the daughter isotopes and the parent isotopes in aging. So, it makes difficult to determine the age of the rocks.

The benefits of Potassium-Argon system is to get a better measurement of the igneous rock by observing the amounts of potassium-40 and argon-40 in which potassium-40 is the parent isotopes while argon-40 is the daughter isotope. Since argon is a gas, so it gets free when the rock melts into magma or larva and when the rocks become cools, new argon is trapped.

4)

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Carbon-14 dating is worked by comparing the three different isotopes of carbon atom and it begins to decay every 5,730 years which is a half-life of C-14.

It is useful for about 50,000 years.

It has been verified by observing the different organisms and the amount of Carbon-14 which is found in them at different times.