Nuclear decay processes

Example H,0+(aq) + HS"(s) - H2S(g) + H20(1). proton emission A nuclear decay process in which a proton is emitted. In proton emission, the mass and charge numbers of the nucleus both decrease by 1. proton-rich nucleus A nucleus that has a low proportion of neutrons and lies below the band of stability. proton transfer equilibrium The equilibrium involving the transfer of a hydrogen ion between an acid and a base. 

There are five fundamental t T)es of nuclear decay process, as listed in Table 22-3. Figure 22-5 on the next page diagrams how nuclear decays affect N and Z. As the figure suggests, the decay process of any particular unstable nuclide depends on the reason for its instability. 

The y rays that accompany many nuclear decay processes can be more dangerous than a or P particles, because y... 

In the last column of Table 7.1, the most popular radioactive precursor nuclide is given together with the nuclear decay process (EC = electron capture, = beta decay) feeding the Mossbauer excited nuclear level. 

HS states by irradiation with light) has contributed to our understanding of the mechanism of the Nuclear Decay Induced Excited Spin State Trapping (NIESST), where the nuclear decay process Co(EC) Fe may be regarded as an internal source for molecular excitation. 

Isospin is a useful concept in that it is conserved in processes involving the strong interaction between hadrons. The use of isospin can help us to understand the structure of nuclei and forms the basis for selection rules for nuclear reactions and nuclear decay processes. While a detailed discussion of the effects of isospin upon nuclear structure, decay, and reactions is reserved for later chapters, a few simple examples will suffice to demonstrate the utility of this concept. 

Nuclear decay processes that are often used to populate Mossbauer isotope excited states are (30) electron capture (electron + proton neutron), / decay (neutron - proton + electron), and isomeric transition (a long half-life nuclear excited state decays to the Mossbauer excited state). In addition, several of the parent nuclides of the heavy isotopes can be populated by a-particle emission. 

KEY CONCEPT PROBLEM 22.10 The following series has two kinds of processes one represented by the shorter arrows pointing right and the other represented by the longer arrows pointing left. Tell what kind of nuclear decay process each arrow corresponds to, and identify each nuclide A-E in the series ... 

Electron capture A nuclear decay process in which an electron outside the nucleus is captured and a proton is converted to a neutron inside the nucleus. 

Many chemical reactions, once begun, can be stopped. For example, a combustion reaction, such as a fire, can be extinguished before it burns itself out. Nuclear decay processes, on the other hand, cannot be stopped. 

High energy particles or rays emitted during the nuclear decay processes. 

Isotope Dating. Carbon-14 and the other isotope dating methods rely on our understanding of the pertinent nuclear decay processes. If the isotope in the particular artifact has a quantitatively well established decay mechanism, the sample can, in principle, be dated. This statement... 

Why are some nuclei radioactive, decaying spontaneously, when others are stable Thermodynamics gives the criterion AG < 0 for a process to be spontaneous at constant T and P. The energy change AE in a nuclear decay process is so great that... 

A nuclear decay process can be represented by an equation in which the sum of the mass numbers and the sum of the atomic numbers must each be equal on both sides of the arrow. 

Name two nuclear decay processes in which characteristic X-rays are possibly emitted. 

Further information about this event has been obtained by studying tracks which nuclear decay processes leave in certain minerals ( 8.1.2). Fission tracks can only persist in minerals that have not been heated because heating above 600°C erases the tracks. The fact that Pu fission tracks have been found in iron meteorites and in lunar samples shows that 244pu existed when the planetary system formed. Because of the short half-life of Pu (8 X10 y) it can be concluded that such mineral samples must have formed within a few hundred million years after the nuclide Pu itself was formed. This is probably also the time for planetary formation. The existence of primordial plutonium indicates that an r-process preceeded the formation of the planets. 

Very recently, multiple tritium-labeled compounds have been synthesized by Cacace and co>vorkers via nuclear decay processes (51-54). The details of their studies will be described in the next section. 

Nuclear decay processes can involve the release of electrons, protons, neutrons, or combinations of these basic particles. 

Beta particles are another type of particle that can be emitted during a nuclear decay process. A beta particle can be either an electron or a positron, which is the antiparticle of an electron. If it is an electron being emitted, one of the neutrons in the nucleus must become a proton to conserve charge in the process. Beta decay increases the number of protons in the nucleus by one and leaves the atomic mass essentially unchanged. 

Indicate whether each of the following nuclides lies within the belt of stability in Figure 21.2 (a) neon-24, (b) chlorine-32, (c) tin-108, (d) polonium-216. For any that do not, describe a nuclear decay process that would alter the neutron-to-proton ratio in the direction of increased stability. [Section 21.2]... 

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