Examples of radioactivity in the following topics:
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- The emission of these rays is called nuclear radioactivity, or simply radioactivity.
- A substance or object that emits nuclear radiation is said to be radioactive.
- Uranium is radioactive whether it is in the form of an element or compound.
- Radium became highly desirable because it was about two million times as radioactive as uranium.
- Marie's radioactive fingerprints on some pages of her notebooks can still expose film.
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- Transuranium elements are those beyond uranium, none of which is stable because of radioactive decomposition.
- None of these elements is stable and each of them decays radioactively into other elements.
- Each of these elements is radioactive, with a half-life much shorter than the age of the Earth.
- Yellow - Radioactive elements: the most stable isotope has a half-life between 800 and 34.000 years.
- Very little is known about these elements due to their extreme instability and radioactivity.
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- Radiometric dating is used to date materials using the decay rate of a radioactive isotope.
- In many cases, the daughter nuclide is radioactive, resulting in a decay chain.
- The mathematical expression that relates radioactive decay to geologic time is:
- Example of a radioactive decay chain from lead-212 (212Pb) to lead-208 (208Pb) .
- Calculate the age of a radioactive sample based on the half-life of a radioactive constituent
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- Radioactive decay is a random process at the single-atom level; is impossible to predict exactly when a particular atom will decay.
- The following equation is used to predict the number of atoms (N) of a a given radioactive sample that remain after a given time (t):
- This relationship between the half-life and the decay constant shows that highly radioactive substances are quickly spent, while those that radiate weakly endure longer.
- A simulation of many identical atoms undergoing radioactive decay, starting with four atoms (left) and 400 atoms (right).
- Nuclear half-life is the time that it takes for one half of a radioactive sample to decay.
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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.
- The SI unit of radioactive activity is the becquerel (Bq), in honor of the scientist Henri Becquerel.
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- Radioactive decay occurs when an unstable atomic nucleus emits particles or light waves.
- Radioactive decay occurs when an unstable atomic nucleus loses energy by emitting energy in the form of emitted particles or electromagnetic waves, called radiation.
- 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.
- In radioactive nuclei with too many neutrons, a neutron can be converted into an electron, called beta particle.
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- Radon gas, the result of radium's radioactive decay, can severely compromise indoor air quality.
- Radon is a dense, colorless, odorless noble gas that occurs naturally in the soil as the product of the radioactive decay of radium; it is a decay product of uranium and thorium, which occur naturally in the Earth's crust.
- Radon decays to form daughters, or decay products, which include radioactive polonium, lead, and bismuth.
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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.
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- It should not be confused with the unit of radioactive activity, the becquerel (Bq).
- Exposure to a radioactive source will give a dose that is dependent on the activity, time of exposure, energy of the radiation emitted, distance from the source, and shielding.
- People use these dosimeters to keep track of exposure, typically if they expect to come in contact with radioactive substances as part of their jobs.
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- Most of the chemistry has been observed only for the first five members of the group; the chemistry of radium is not well established due to its radioactivity.
- All isotopes of radium are radioactive.
- The other non-radioactive members of the group are only present in smaller quantities.
- Radium, with a maximum half-life of 1,601 years, is only present in nature when it is resupplied by a decay chain from the radioactive decay of heavier elements.
- Radium has a low availability and is highly radioactive, making it toxic to life.