Nuclear chemistry electron capture

This is the last chapter in Part I of the general chemistry review. In this chapter, we will discuss the different aspects of radioactivity. Radioactivity is a nuclear phenomenon. It results from natural nuclear instability or externally induced nuclear instability. We will limit our discussion of nuclear chemistry to the basic aspects of radioactivity involving radioactive emissions such as alpha emission, beta emission, gamma rays, positron emission, and electron capture. We will also review other ideas such as the half-lives of radioactive substances and the mass-energy equation. 

All isotopes of astatine are radioactive. The longest lived isotope is astatine-210, which has a half-life of 8.1 hr and decays mainly by electron capture. Because astatine is so unstable to nuclear decay, very little is known about its chemistry. 

A short description of possible nuclear applications of boron-based materials had been done by Potapov (1961) in an old overview that included the nuclear power industry (e.g., control rods of nuclear reactors) solid-state electronics (e.g., counters of neutrons and neutron energy sensors) radiation chemistry (e.g., acceleration of technological processes) etc. For these purposes, "B nuclei are useless, but °B nuclei are useful due to a large cross section of interaction with thermal neutrons, °B converts them into heavy ionizing particles. Besides, °B isotope is applicable for neutron radiation protection (Stantso 1983) and also in medicine, e.g., in boron neutron capture therapy (BNCT) for treating cancer tumors (Desson 2007). 

We can see that an a-particle is a nucleus of He as the dication He " ". When electrons are given off from a nuclear reaction they are called (3-particles and electrons can be absorbed or emitted. In some heavy elements. Is electrons can sometimes be captured into a nucleus and combine with a proton to form an additional neutron in the nucleus which reduces the number of protons and changes the elements atomic number (Z) to (Z — 1) as Je + H —> Jn. Thus, for the purpose of chemistry we can regard a neutron as the combination of an electron and a proton. While this has been controversial in the past it is known that neutrons are unstable outside a nucleus and they decay into an electron and a proton as Jn -1 + H with (1/2= 10.3 min. 

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