Beta particles properties

The nuclear reactor also must be shielded against the emission of radioactive material to the external environment. Suitable radiation controls include both thermal and biological shielding systems. Radiation from alpha particles (a rays) and beta particles ((3 rays) has little penetrating power, but gamma rays have deep penetration properties. Neutron radiation is, however, the primary area of risk. Typically, extremely thick concrete walls are used as a neutron absorber, but lead-lined concrete and special concretes are also used. 

The numerical combination of protons and neutrons in most nuclides is such that the nucleus is quantum mechanically stable and the atom is said to be stable, i.e., not radioactive however, if there are too few or too many neutrons, the nucleus is unstable and the atom is said to be radioactive. Unstable nuclides undergo radioactive transformation, a process in which a neutron or proton converts into the other and a beta particle is emitted, or else an alpha particle is emitted. Each type of decay is typically accompanied by the emission of gamma rays. These unstable atoms are called radionuclides their emissions are called ionizing radiation and the whole property is called radioactivity. Transformation or decay results in the formation of new nuclides some of which may themselves be radionuclides, while others are stable nuclides. This series of transformations is called the decay chain of the radionuclide. The first radionuclide in the chain is called the parent the subsequent products of the transformation are called progeny, daughters, or decay products. 

Uranium-238 emits an alpha particle to become an isotope of thorium. This unstable element emits a beta particle to become the element now known as Protactinium (Pa), which then emits another beta particle to become an isotope of uranium. This chain proceeds through another isotope of thorium, through radium, radon, polonium, bismuth, thallium and lead. The final product is lead-206. The series that starts with thorium-232 ends with lead-208. Soddy was able to isolate the different lead isotopes in high enough purity to demonstrate using chemical techniques that the atomic weights of two samples of lead with identical chemical and spectroscopic properties had different atomic weights. The final picture of these elements reveals that there are several isotopes for each of them. 

McMillan and Abelson predicted that the radioactive element 2 39Np would decay by emission of beta particles to form an element of atomic number 94. This prediction was confirmed in 1940 by Glenn Seaborg, McMillan, Wahl, and Kennedy, who produced element 94 and made detailed studies of its chemical properties ... 

Although there are two types of (3-particles ((3 and (3 ), the former is usually referred to as a positron, so we ll refer to only the (3 particle as a beta particle. In a beta emission, a beta particle is ejected from the atom. A beta particle has all of the properties of an electron (virtually massless, negative charge), yet it is created by the conversion of a neutron in the nucleus to a proton and an electron (beta particle). The proton remains in the nucleus, and the beta particle is ejected from the nucleus. An example of a beta emission is ... 

The ionizing properties of Pu and other radioactive materials is one determinant of the level of hazard associated by different exposure routes. Radioactive elements are those that undergo spontaneous transformation (decay) in which energy is released either in the form of particles, such as alpha or beta particles, or waves, such as gamma or X-ray. Plutonium exists in several isomeric forms, the most important of which are Pu-238 and Pu-239. When these isotopes decay, they emit primarily alpha particles, which are densely ionizing and, therefore, damaging however, the penetration of alpha particles into tissue is slight, so... 

Strontium can also exist as several radioactive isotopes, the most common is °Sr. Strontium-90 is formed in nuclear reactors or during the explosion of nuclear weapons. Radioactive strontium generates beta particles as they decay. One of the radioactive properties of strontium is half-life, or the time it takes for half of the isotope to give off its radiation. 

Radioactivity - The property possessed by some elements (as uranium) or isotopes (as cardon-14) of spontaneously emitting energetic particles such as alpha or beta particles, often accompanied by gamma rays, by the disintegration of their atomic nuclei. 

Alpha Particles Beta Particles Gamma Rays Properties of Alpha, Beta, and Gamma Radiation... 

In 1911, the British physicist and Nobel laureate Ernest Rutherford (1871-1937) published the article The Scattering of Alpha and Beta Particles by Matter and the Structure of the Atom in Philosophical Magazine. In this article, Rutherford reported the results of an experiment that demonstrated that the protons and electrons in atoms are not distributed homogeneously. Instead, the protons are concentrated in a relatively tiny region Rutherford called the nucleus (from the Latin, meaning kernel ). The electrons are extranuclear electrons are located in a relatively much larger volume of space surrounding the nucleus. Rutherford s discovery of the nucleus was immediately accepted within the scientific community. However, the relationship, if any, between atomic structure and properties was still unclear. 

Li et al. (69) reported the preparation of nanosized Sn-beta particles by a postsynthesis modification. Highly dealuminated beta zeoHte underwent a gas-solid reaction with SnCl4 vapor at elevated temperature. The properties of the resultant Sn-beta sample were characterized by various techniques. It was inferred that the tin species were inserted into the framework via reaction of SnCl4 with sdanol groups in hydroxyl nests that had been created during the dealumination. The tin thus predominately occupied sites with tetrahedral coordination. The tin content that could be achieved by this postsynthesis method was as high as 6.2 wt%, corresponding to a Sn/(Si +Sn) ratio of 0.034. 

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