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How the radioactive decay of isotopes is used to determine the age of rocks?
Wiki User
∙ 8y ago
The amount of the remaining radioactive isotopes it contains.
Trever Windler
Laurence Aufderhar
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Wiki User
∙ 13y agoWe use carbon -14 isotope for dating. The half life of carbon-14 is 5570 years. BY estimating the ratio of Carbon 14 present at this moment against the carbon-12 we can compute the age of the relics. If 50% of carbon 14 remains then we can say the age will be 5570 years. If 25% remains then the age elapsed has to be 2*5570 ie 11140 years.
answer 2 Because of the relatively short half-life of C14, its use is mainly restricted to archaeological items, or recent organic remains.
Many other radioactive schemes are used for other geological studies.
Some of the potassium in your body is decaying into Argon, K40 - Ar40. [K40 has a half-life of 1.3 x109 years. ]
This transition is frequently used to determine the age of material (such as lava) that has solidified. Before it solidified, any Ar would have evaporated, so any Ar present today has most probably been made since the rock cooled. And the frozen structure of the rock would have held any 'new' Ar.
Similarly with various Uranium to Lead transitions. And even Uranium - Uranium transitions. There are many many of them.
Wiki User
∙ 13y agoThis is Ar/Ar dating, (carbon dating is for living organisms). When Ar is expelled from the earth, it starts off as a specific radioactive isotope of argon. The argon will break down and form other Ar isotopes at a set rate known as a half-life. The concentration of the isotopes is used to determine the age of the rock
Wiki User
∙ 14y agoWhen a rock crystallises from a melt (igneous) certain radioactively unstable isotopes within the crystals develop at the time of formation. Starting when the melt solidifies these unstable parent isotopes begin to decay into their daughter isotopes. Radiometric/Isotopic dating uses the ratio of parent to daughter isotopes to determine when the rock formed. For example say you have a parent isotope A and it decays into its daughter isotope B and A takes 10000 years to reach its half life, if there is a 50:50 ratio of A:B then the rock is 10000 years old if there is a ratio of 75:25 then 5000 years have passed since its formation from melt and 25:75 then 15000 years have passed. The most common isotopes used are Rubidium:Strontium and Potassium:Argon but there are many others. In metamorphic rocks the parent daughter isotope method can only tell you the time of the metamorphosis not the formation of the original rock. Sedimentary rocks cannot be dated this way, the only dating of this kind that can be carried out on them is Carbon 14 dating and only gives dates as far as 50,000 years ago.
Wiki User
∙ 13y agoIn rocks, radioisotopes such as Uranium decay with half-lives of millions or even perhaps billions of years, depending on the isotope. When the rock was first formed, there is a certain amount of Uranium, compared to a substance like Lead, which is a product when Uranium decays. As time passes, this Uranium decays into Lead and the amount of Uranium decreases while that of Lead increases. Using the ratios, the age of the rock can be determined easily. Carbon dating cannot be used on rocks because it is not accurate for objects older than 80 000 years old. Carbon dating is only suitable for finding the age of fossils.
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Radioactive dating of rock samples is a method?
used to determine the age of rocks and minerals by measuring the abundance of certain radioactive isotopes within them. This method relies on the fact that radioactive isotopes decay at a known rate over time. By measuring the ratio of parent isotopes to daughter isotopes, scientists can calculate how long it has been since the rock or mineral formed.
What would you use to do absolute dating of a rock layer?
There are several ways to do absolute dating of a rock layer. One of these is to use the radioactive decay of the isotopes that are naturally found in rocks.
What knowledge is radiometric dating based upon?
radiometric dating is base on the half life of the radioactive atoms
How do scienistuse the rate at which radioactive elements decay on rocks?
give a irect answer ^
Do radioactive elements decay naturally and release energy as they lose particales from their nuclei?
Yes. Naturally occurring radioactive isotopes decay naturally. They can be induced to decay more rapidly through neutron capture, but they will decay one way or the other. Among the commonly encountered, or commonly mentioned isotopes that do this are radon-222, which comes as a gas from many kinds of rocks and is found in the basements of some buildings, carbon-14, which is used for carbon dating, and potassiom-40, which is found in all living tissue.
Geologists determine the absolute age of rocks using?
Geologists determine the absolute age of rocks using radiometric dating techniques, such as carbon dating or uranium-lead dating. These methods rely on measuring the proportions of radioactive isotopes and their decay products in the rocks to calculate how long ago they formed.
Radioactive dating of rock samples is a method?
used to determine the age of rocks and minerals by measuring the abundance of certain radioactive isotopes within them. This method relies on the fact that radioactive isotopes decay at a known rate over time. By measuring the ratio of parent isotopes to daughter isotopes, scientists can calculate how long it has been since the rock or mineral formed.
What property of radioactive isotopes allow them to be used to determine the age of rocks and fossils?
Their half life.
To determine the most accurate and precise age of the earths oldest rocks What would geologists use?
They would use absolute dating techniques which rely on the decay of radioactive isotopes found in association with the rock.
What is potassium-argon dating?
The radioactive decay of potassium 40 produces in argon 40. The proportion of these two isotopes in rocks permit their age to be calculated.
What is potassium argon dating?
The radioactive decay of potassium 40 produces in argon 40. The proportion of these two isotopes in rocks permit their age to be calculated.
Why are radioactive materials used to date rocks rocks?
Radioactive materials decay at predictable rates
How do scientists use the halflife of radioactive isotopes to date rocks and fossils?
The basic idea is to compare the abundance of a naturally occurring radioactive isotope within a material to the abundance of its decay products; it is known how fast the radioactive isotope decays.
What is Radioactive dating of rock samples?
Radioactive dating of rock samples determines the age of rocks from the time it was formed. Geologist determine the age of rocks using radioactive dating. The radioactive dating relies on spontaneous decomposition into other element. The spontaneous decomposition is called radioactive decay.
Why radioactive decay use to determine the absolute age of rocks?
**this happens because it does. is a common answer i receive but is not true. BUT the answer IS that radioactive decay is used to determine the ABSOLUTE age of rocks because it is more accurate, and because when you put radioactive decay and you put a rock there, you see a process going on. correct me if I'm wrong but i believe that using this is receive don't listen to what i say below: When you take radioactive material, and you put a solid in there, what happens? COMBUSTION! this is caused by a CHEMICAL REACTION. so common sense tells me that when you put radioactive decay to determine a rocks absolute age, its common knowledge that they use it for accuracy, and they take the age and see how old it (the rocks) are. that's how they know the age of rocks. (look in your every day science book it should say) hope this helped :3 :D **
Why is radioactive decay used to determine the absolute ages of rocks?
**this happens because it does. is a common answer i receive but is not true. BUT the answer IS that radioactive decay is used to determine the ABSOLUTE age of rocks because it is more accurate, and because when you put radioactive decay and you put a rock there, you see a process going on. correct me if I'm wrong but i believe that using this is receive don't listen to what i say below: When you take radioactive material, and you put a solid in there, what happens? COMBUSTION! this is caused by a CHEMICAL REACTION. so common sense tells me that when you put radioactive decay to determine a rocks absolute age, its common knowledge that they use it for accuracy, and they take the age and see how old it (the rocks) are. that's how they know the age of rocks. (look in your every day science book it should say) hope this helped :3 :D **
What would you use to do absolute dating of a rock layer?
There are several ways to do absolute dating of a rock layer. One of these is to use the radioactive decay of the isotopes that are naturally found in rocks.
