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How do scientists use the halflife of radioactive isotopes to date rocks and fossils?
Wiki User
∙ 8y ago
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.
Wiki User
∙ 8y ago
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How can carbon dating be used in materials?
Carbon dating is mainly used by archaeologists to date recent finds as the technique is only accurate for 50,000 to 60,000 years in the past. To date fossils, or rather the rocks in or near where the fossils are found, we use radioactive isotopes which have a much greater half life.
How does radioactive dating relate to fossils and radioactive waste?
There are a number of types of radiometric dating. Carbon-14 dating, which is perhaps best known, can only be used for things some thousands of years old at most, and so is not particularly useful for fossils. Other types of radiometric dating, however, are good for hundreds of thousands or millions of years, and these are very useful for fossils. In fact they can be used to estimate the ages of various kinds of rocks. Radioactive waste is a pollutant that affects some radiometric dating techniques, skewing them. For example, above ground nuclear testing in the 1950s and 1960s produced waste carbon-14, almost doubling the amount in the atmosphere for some time. This would make samples from that period appear too new. Most radioactive materials in nuclear waste or pollution would not have this sort of effect, however. In order to influence radiometric dating, the material measured has to be part of the pollution or has to be generated from it. Carbon-14 results from a collision of a neutron with nitrogen-13 (a hydrogen atom is also generated). But this happens in the upper atmosphere as a result of cosmic rays. There are very few sources of neutrons on Earth, with uranium-235 probably being the most common. So ordinary nuclear waste from such sources as power plants will not usually skew carbon-14 dating. On the other hand, the isotopes other than carbon-14 that are used in radiodating may be among those in nuclear waste. Among the isotopes that might be affected are those used in iodine-xenon dating, rubidium-strontium, and potassium-argon dating. Nuclear pollutants might include these isotopes in them, and so exposure would possibly skew results. There are other forms of pollution that affect carbon dating. Burning of fossil fuels increases the amount of carbon dioxide in the atmosphere without increasing the amount of carbon-14. This would make some samples from the period after about 1700 appear too old.
Why is radioactive decay is good method of measuring the absolute age of ancient fossils?
There are different types of atoms with the same chemical properties but with different numbers of neutrons in the atomic nucleus. These are called "isotopes". The most common element in most living organisms is carbon, which comes in two isotopes; carbon 12, which is normal ordinary carbon and carbon 14, which is very slightly radioactive. The radioactivity means that it will decay, changing into some other element, very slowly. The proportion of carbon 12 to carbon 14 is pretty steady, so as living things grow, they take in carbon 12 and carbon 14 in their food and air. When the plant or animal dies, they stop taking in new carbon. The carbon 12 remains the same, while the carbon 14 decays into something else very slowly. When we find the remains or the fossil of the dead animal or plant, we can measure how much carbon 12 and how much carbon 14 there is, and calculate how long it has been since the animal died.
How is the rate of radioactive decay measured?
Nothing, it is purely a random quantum mechanical process.But there are many ways to measure it. Once you can measure it though the results can be used in many ways including making very accurate estimates of the ages of bodies that died thousands of years ago, fossils, rocks, etc.
How does carbon dating or radioactive dating work and why is it used?
Everything has carbon in it. When the organism dies, it begins to disintegrate. We know the rate at which things disintegrate at, so we can determine how much carbon is left and then apply a scientific formula and figure out how old the organism is. Radioactive dating works much the same.
Scientists use the amount of radioactive isotopes found in rocks and fossils to calculate their ages this process is called?
the rock and the fossils are made out of lava stuff
What can scientists learn from the rate at which radioactive elements decay?
fossils
What property of radioactive isotopes allow them to be used to determine the age of rocks and fossils?
Their half life.
How isotopes can be used to benefit humans?
Doctors can use radioactive isotopes to treat certain types of cancer, such as prostate cancer. Geologists use isotopes to date some rocks and fossils.
True or False Fossils may be dated by either the relative dating method which determines the relative order of fossils or by the absolute dating method which uses radioactive isotopes?
True
What is the process called when scientists use radioactive isotopes to calculate a fossils age?
Radioactive elements tend to degrade or give off radiation at a constant rate. That is an essential part of radioactive carbon dating. Uranium, for instance has a has half life of 5,400 years. Each 5,400 years, half of the uranium becomes inert lead. It is considered an accurate form of dating.
What are three uses of isotopes?
Carbon-14 is used to determine the age of fossils. Radiation therapy for cancer comes from isotopes that emit gamma rays. Thyroid tissue that may be cancerous and has left the throat region can be located in the body with radioactive iodine.
Why is gamma used for a radioactive tracer?
Isotopes are used as tracers in many medical settings. Radioactive isotopes are used to identify abnormal bodily processes. The isotopes can also be used in plants to measure the amount of radioactivity in the leaves.
Measurements of half-life make radioactive isotopes useful for?
They're useful for x-rays or looking at metals,or determining the age of rocks/fossils. (Hope it helped!😁)
How are radioactive isotopes helpful for studying rocks and fossils?
Radioactive isotopes can be used to determine how old a rock or fossil is. One method is based on 14C (or Carbon 14) which has a half life of 5,730 years. Scientists know the ratio of 12C to 14C in plant materials based on absorption of CO2 is relatively constant1, but that the creation of 14C stops at death. With this knowledge, if you measure the ratio of 12C to 14C you can estimate how long ago the sample was alive. ---------------------------------------------------------------- 1Technically, the 14C levels have changed over the years due to various geologic, astronomic, and technologic issues, so scientists also compensate for that knowledge when they calibrate a particular sample.
Why is burning of fossils is a concern for scientists?
Because the burning of fossils is a pollution to the air & our environment & that's why its a concern for the scientists
How do radioactive elements be used to date fossils?
brick
