Examples of radioactive isotopes in the following topics:
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- Radiometric dating is used to date materials using the decay rate of a radioactive isotope.
- It is based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.
- In many cases, the daughter nuclide is radioactive, resulting in a decay chain.
- Here, t is age of the sample; D is number of atoms of the daughter isotope in the sample; D0 is number of atoms of the daughter isotope in the original composition; N is number of atoms of the parent isotope in the sample at time t (the present), given by N(t) = Noe-λt; and λ is the decay constant of the parent isotope, equal to the inverse of the radioactive half-life of the parent isotope times the natural logarithm of 2.
- Calculate the age of a radioactive sample based on the half-life of a radioactive constituent
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- Mass spectrometry has been used to study the ratio of carbon isotopes in various plants to understand the mechanisms of photosynthesis.
- Mass spectrometry has been used to study the ratio of isotopes in various plants to understand the mechanisms of photosynthesis.
- Stable carbon isotopes in carbon dioxide are utilized differentially by plants during photosynthesis.
- Grasses in temperate environments, such as barley, rice, and wheat, follow a C3 photosynthetic pathway that yields distinctive isotopic ratios.
- Describe the use of radioactive isotopes in the study of photosynthesis
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- Green - Radioactive elements: the most stable isotope is very long-lived, with s half-life of over four million years.
- Yellow - Radioactive elements: the most stable isotope has a half-life between 800 and 34.000 years.
- Orange - Radioactive elements: the most stable isotope has a half-life between one day and 103 years.
- Red - Highly radioactive elements: the most stable isotope has a half-life between several minutes and one day.
- Purple - Extremely radioactive elements: the most stable isotope has a half-life less than several minutes.
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- Nuclear medicine is a medical specialty that involves the application of radioactive substances to diagnose or treat disease.
- Nuclear medicine is a medical specialty that involves the application of radioactive substances in the diagnosis and treatment of a disease.
- Common isotopes that are used in nuclear imaging include: fluorine-18, gallium-67, krypton-81m, rubidium-82, nitrogen-13, technetium-99m, indium-111, iodine-123, xenon-133, and thallium-201.
- For this type of therapy, yttrium-90 and iodine-131 are the most commonly used isotopes.
- These images are scans used in the evaluation of thyroid cancer using the isotope iodine-123.
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- Isotopes do differ in their stability.
- Neutrons, protons, and positrons can also be emitted and electrons can be captured to attain a more stable atomic configuration (lower level of potential energy) through a process called radioactive decay.
- These atoms are called radioactive isotopes or radioisotopes.
- Other elements have isotopes with different half lives.
- Scientists often use these other radioactive elements to date objects that are older than 50,000 years (the limit of carbon dating).
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- NMR analysis is isotope-dependent, and it often relies on trace isotopes of a molecule for detection.
- Adding an isotope will also change the observed mass of any fragment which contains the isotope.
- Isotopic labeling is used to track the passage of an isotope through a reaction, metabolic pathway, or cell.
- In isotopic labeling, there are multiple ways to detect the presence of labeling isotopes: mass, vibrational mode, or radioactive decay.
- The radioactive decay can be detected through an ionization chamber or autoradiographs of gels.
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- Radioactive decay occurs when an unstable atomic nucleus emits particles or light waves.
- Isotopes are atoms of the same element (thereby having the same number of protons) which differ in the number of neutrons in their nucleus.
- Some isotopes of a given element are more unstable than others, causing a nuclear reaction which releases energy to achieve a more stable nuclear configuration.
- Such isotopes are radioactive, and are referred to as "radioisotopes."
- The higher the energy, the more the particles or light produced by radioactive decay will penetrate a substance.
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- However, if neutron count surpasses an ideal ratio, a nucleus becomes unstable and can undergo radioactive decay.
- Among elements of atomic number 1-82, only two (technetium and promethium) lack at least one isotope considered to be stable.
- Only 90 isotopes in this region are believed to be perfectly stable, while 163 more are understood to be theoretically unstable but have never been observed to decay.
- Technetium and promethium, as well as elements of number 83 and above, have only isotopes that will decay over time.
- Stability of isotopes is shown as a function of proton and neutron numbers.
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- Each isotope has different chemical properties.
- It is radioactive, decaying into helium-3 through beta-decay accompanied by a release of 18.6 keV of energy.
- It is a highly unstable isotope of hydrogen.
- 5H is another highly unstable heavy isotope of hydrogen.
- Unique among all stable isotopes, it has no neutrons.
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- The decay rate of a radioactive substance is characterized by the following constant quantities:
- The mean lifetime (τ, "tau") is the average lifetime of a radioactive particle before decay.
- Total activity (A) is number of decays per unit time of a radioactive sample.
- Radioactivity is one very frequent example of exponential decay.
- Another unit of radioactivity is the curie, Ci, which was originally defined as the amount of radium emanation (radon-222) in equilibrium with one gram of pure radium, isotope Ra-226.