Radioactive decay modes

Fission and fusion are different from other radioactive decay modes because they won t happen spontaneously. For this reason, they need some kind of catalyst or special conditions to make them happen. Examples include the... 

FIGURE 1.1 Schematic ofradioactive decay modes. (Promhttp //upload.wildmedia.org/ wikipedia/commons/thumb/7/71/Radioactive decay modes.svg/201px-Radioactive decay modes.svg.png, accessed July 26, 2014.)... 

There are four modes of radioactive decay that are common and that are exhibited by the decay of naturally occurring radionucHdes. These four are a-decay, j3 -decay, electron capture and j3 -decay, and isomeric or y-decay. In the first three of these, the atom is changed from one chemical element to another in the fourth, the atom is unchanged. In addition, there are three modes of decay that occur almost exclusively in synthetic radionucHdes. These are spontaneous fission, delayed-proton emission, and delayed-neutron emission. Lasdy, there are two exotic, and very long-Hved, decay modes. These are cluster emission and double P-decay. In all of these processes, the energy, spin and parity, nucleon number, and lepton number are conserved. Methods of measuring the associated radiations are discussed in Reference 2 specific methods for y-rays are discussed in Reference 1. 

The pattern of nuclear stability can be used to predict the likely mode of radioactive decay neutron-rich nuclei tend to reduce their neutron count proton-rich nuclei tend to reduce their proton count. In general, only heavy nuclides emit a particles. 

Capture, Electron—A mode of radioactive decay involving the capture of an orbital electron by its nucleus. Capture from a particular electron shell, e.g., K or L shells, is designated as "K-electron capture" or "L-electron capture."... 

The first four modes of radioactive decay can be plotted on a single diagram (Fig. 10.3), which allows for a prediction of the nature of the daughter nucleus from a parent subject to any one of the above processes. 

Figure 10.3 Schematic diagram of the four common modes of radioactive decay.

ISOTOPES There are a total of 30 isotopes of protactinium. All are radioactive, and none are stable. Their decay modes are either alpha or beta decay or electron capture. Their half-lives range from 53 nanoseconds to 3.276x10+ ears. 

ISOTOPES There are a total of 15 Isotopes for rutherfordlum, ranging from Rf-253 to Rf-264. Their half-lives range from 23 microseconds to 10 minutes. They are all artificially made, radioactive, and unstable. Their decay modes are a combination of alpha decay and spontaneous fission (SF). 

Symbol Bk atomic number 97 atomic weight of most stable isotope 247.07 a transuranium radioactive element synthesized in the laboratory electronic configuration [Rn]5/97s2 oxidation states -i-3 and +4. Isotopes, half-hfe and decay modes are given below ... 

Symbol Cm atomic number 96 atomic weight 247 a radioactive transuranium actinide series element electron configuration [Rn]5/ 6di7s2 most stable valence state +3 most stable isotope Cm-247. Curium isotopes, half-hves and decay modes are ... 

Symbol Fr atomic number 87 atomic weight 223 heaviest adtah metal element of Group lA (Group 1) a radioactive element electron configuration [Rn]7sk oxidation state -i-l the most electropositive element the most stable isotope, Fr-223 (ti/2 21 minutes), also is the only natural isotope. Isotopes, half-lives and their decay modes are shown below ... 

Most of the challenges associated with the handling of short-lived positron emitters are direct consequences of their physical properties, half-life and decay mode, from which also ensues very high maximum specific radioactivity and the associated practical minute amounts of material engaged in the radiosyntheses. 

Many radioisotopes exist, but not all radioisotopes are created equal. Radioisotopes break down through three separate decay processes (or decay modes) alpha decay, beta decay, and gamma decay. The following sections show you equations detailing each type of decay. Note The symbols showing the isotope notation for each radioactive isotope cire as follows or 2 Y, where... 

Effects of different modes of radioactive decay on the position of an isotope on the Chart of the Nuclides. Beta-decay, which changes a neutron to a proton, moves the nuclide up and to the left. Positron decay or electron capture, which changes a proton into a neutron, moves the nuclide down and to the right. And -decay, which is the emission of a 4He nucleus, moves the nuclide down and to the left. 

Exotic Nuclei and Their Decay. As reported by J.C. Hardy (Chalk River Nuclear Laboratories. Atomic Energy of Canada, Ltd.), recent advances in nuclear accelerators and experimental techniques have led to an increasing ability to synthesize new isotopes. As isotopes are produced with more and more extreme combinations of neutrons and protons in their nuclei, new phenomena are observed, and the versatility of the nucleus is increased as a laboratory for studying fundamental forces. Hardy reports that, among the newly discovered decay modes are (1) proton radioactivity, (2) triton, two-proton, two-neutron, and three-neutron decays that are beta-delayed, and (3) 14C emission m radioactive decay, Precise tests of the properties of the weak force have also been achieved. 

Hofmann, S. Proton Radioactivity, In D. N. Poenaru (Ed.), Nuclear Decay Modes, IOP, Bristol, 1996. 

Internal transition A mode of radioactive decay, where an excited nucleus transfers energy to an electron and expels the electron from the atom. Internal transition is responsible for transforming certain arsenic isomers from higher to lower energy states (Table 2.1). 

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