Examples of radioactive decay in the following topics:
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- Radioactive decay series describe the decay of different discrete radioactive decay products as a chained series of transformations.
- Radioactive decay series, or decay chains, describe the radioactive decay of different discrete radioactive decay products as a chained series of transformations.
- Most radioactive elements do not decay directly to a stable state; rather, they undergo a series of decays until eventually a stable isotope is reached.
- For example, natural uranium is not significantly radioactive, but pitchblende, a uranium ore, is 13 times more radioactive because of the radium and other daughter isotopes it contains.
- Not only are unstable radium isotopes significant radioactivity emitters, but as the next stage in the decay chain they also generate radon, a heavy, inert, naturally occurring radioactive gas.
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- Beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted from an atomic nucleus.
- Beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted from an atomic nucleus, as shown in .
- There are two types of beta decay.
- Beta decay is mediated by the weak force.
- A beta-stable nucleus may undergo other kinds of radioactive decay (for example, alpha decay).
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- Gamma decay is a process of emission of gamma rays that accompanies other forms of radioactive decay, such as alpha and beta decay.
- Gamma rays from radioactive decay are defined as gamma rays no matter what their energy, so there is no lower limit to gamma energy derived from radioactive decay.
- Gamma decay accompanies other forms of decay, such as alpha and beta decay; gamma rays are produced after the other types of decay occur.
- Path of decay of Co-60 to Ni-60.
- Explain relationship between gamma decay and other forms of nuclear decay.
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- Also, only four naturally occurring, radioactive odd-odd nuclides have a half-life greater than a billion years:
- During this process, the radionuclide is said to undergo radioactive decay.
- Radioactive decay results in the emission of gamma rays and/or subatomic particles such as alpha or beta particles, as shown in .
- Alpha decay is one type of radioactive decay.
- Many other types of decay are possible.
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- Gamma rays are very high frequency electromagnetic waves usually emitted from radioactive decay with frequencies greater than 1019 Hz.
- Gamma rays from radioactive decay are defined as gamma rays no matter what their energy, so that there is no lower limit to gamma energy derived from radioactive decay.
- Gamma radiation from radioactive materials is used in nuclear medicine.
- Exceptions to this convention occur in astronomy, where gamma decay is seen in the afterglow of certain supernovas, but other high energy processes known to involve other than radioactive decay are still classed as sources of gamma radiation.
- A notable example is extremely powerful bursts of high-energy radiation normally referred to as long duration gamma-ray bursts, which produce gamma rays by a mechanism not compatible with radioactive decay.
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- Through radioactive decay, nuclear fusion and nuclear fission, the number of nucleons (sum of protons and neutrons) is always held constant.
- Consider the three modes of decay.
- In gamma decay, an excited nucleus releases gamma rays, but its proton (Z) and neutron (A-Z) count remain the same:
- In beta decay, a nucleus releases energy and either an electron or a positron.
- Alpha decay is the only type of radioactive decay that results in an appreciable change in an atom's atomic mass.
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- By virtue of its consequent radioactive decay, this compound can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products.
- In a tracer, this substituting atom is a radioactive isotope.
- This process is often called radioactive labeling.
- Radioactive decay is much more energetic than chemical reactions.
- There are two main ways in which radioactive tracers are used:
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- An artefact is found to have radioactivity of 4 dpm per gram of its present C.
- The following figure shows a simulation of many identical atoms undergoing radioactive decay.
- The relationship between the half-life and the decay constant shows that highly radioactive substances are quickly spent while those that radiate weakly endure longer.
- These marker-times reflect a fundamental principle only in that they show that the same proportion of a given radioactive substance will decay over any time period you choose.
- A simulation of many identical atoms undergoing radioactive decay, starting with four atoms (left) and 400 atoms (right).
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- Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle that consists of two protons and two neutrons, as shown in .
- Alpha decay is the most common cluster decay because of the combined extremely high binding energy and relatively small mass of the helium-4 product nucleus (the alpha particle).
- Alpha decay typically occurs in the heaviest nuclides.
- Alpha decay is one type of radioactive decay.
- Many other types of decay are possible.
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- Radioactive material is found throughout nature.
- Some of these decay products, like radium and radon, are intensely radioactive but occur in low concentrations.
- Most of these sources have been decreasing, due to radioactive decay since the formation of the earth, because there is no significant source of replacement.
- Many shorter-half-life and therefore more intensely radioactive isotopes have not decayed out of the terrestrial environment because they are still being produced.
- Examples of these are radium-226 (a decay product of uranium-238) and radon-222 (a decay product of radium-226).