Beta-particles

The beta particle formed when a neutron converts to a proton equivalent to an electron ( iP). 

The most important types of radioactive particles are alpha particles, beta particles, gamma rays, and X-rays. An alpha particle, which is symbolized as a, is equivalent to a helium nucleus, fHe. Thus, emission of an alpha particle results in a new isotope whose atomic number and atomic mass number are, respectively, 2 and 4 less than that for the unstable parent isotope. 

Beta particles, [3, come in two forms. A negatron, i[3, is equivalent to an electron, and is produced when a neutron is converted to a proton, increasing the atomic number by 1. 

Emission of an alpha or beta particle often produces an isotope in an unstable, high-energy state. This excess energy is released as a gamma ray, y, or an X-ray. Gamma ray and X-ray emission may also occur without the release of alpha or beta particles. 

The radioactive isotope of 13AI has a characteristic decay process that includes the release of a beta particle and a gamma ray. 

Natural radioactive processes in themselves give rise to changes of one element into another. Emission of an alpha particle reduces the atomic number of an element by two units, and emission of a beta particle increases the atomic number by one unit. Thus, for isotopes of elements near... 

For example, after successively emitting eight helium nuclei and six beta particles from the end result is the non-radioactive Pb isotope. 

Similarly, emits seven helium nuclei and 4 beta particles during its transition through several other elements, until Pb is reached and Th starts the successive elimination of six helium nuclei and 4 beta particles, which leads to Pb. 

The 140 KeV photons emitted by Tc are accompanied by few conversion and Auger electrons and no beta-particles which increase the radiation dose without adding to the imaged information, and no gamma- or x-rays of other energies. These other gamma- or x-rays, if substantially lower in energy. 

Rubidium-87 emits beta-particles and decomposes to strontium. The age of some rocks and minerals can be measured by the determination of the ratio of the mbidium isotope to the strontium isotope (see Radioisotopes). The technique has also been studied in dating human artifacts. Rubidium has also been used in photoelectric cells. Rubidium compounds act as catalysts in some organic reactions, although the use is mainly restricted to that of a cocatalyst. 

The isotope Cs, = 2.05 yr, emits a beta particle and is useflil in radio autography (48). Research into the use of the stable Cs isotope and... 

Beta particles and photon emitters none 4 millirems per year Increased risk of cancer Decay of natural and manmade deposits... 

Gamma ray The shortest wavelength and highest energy type of all electromagnetic radiation. It originates in the nucleus of radioactive isotopes along with alpha particle, beta particle, or neutron emissions. 

Briefly describe radioactive transformations, particularly as they apply to beta particle emissions. 

Radioactive transformations are accomplished by several different mechanisms, most importantly alpha ptirticle, beta particle, tuid gamma ray emissions, Each of tliese mechanisms are sponuuieous nuclear transformations. The result of these transformations is tlie formation of different tuid more stable elements. 

Several different mechanisms, most importtuitly alplia particle, beta particle, and gamma ray emissions accomplish radioactive transformations. Each of these mechanisms is a spontaneous nuclear transformation. Tlie result of tliese transformations is the formation of different stable elements. Tlie kind of transformation that will ttike place for any given radioactive element is a function of the type of nuclear inslabilitv as well as the mass/energy relationship. The nuclear instability is dependent on the ratio of neutrons to... 

When a uranium-235 atom undergoes fission, it splits into two unequal fragments and a number of neutrons and beta particles. The fission process is complicated by the fact that different uranium-235 atoms split up in many different ways. For example, while one atom of 292U is splitting to give isotopes of rubidium (Z = 37) and cesium (Z = 55), another may break up to give isotopes of bromine (Z = 35) and lanthanum (Z = 57), while still another atom yields isotopes of zinc (Z = 30) and samarium (Z = 62) ... 

Lead-210 has a half-life of 20.4 years. This isotope decays by beta particle emission. A counter registers 1.3 X 104 disintegrations in five minutes. How many grams of Pb-210 are there ... 

Consider file fission reaction in which U-235 is bombarded by neutrons. The products of the bombardment are rubidium-89, cerium-144, beta particles, and more neutrons. 

A 100.0-g sample of water containing tritium, H, emits 2.89 X 103 beta particles per second. Tritium has a half-life of 123 years. What percentage of all the hydrogen atoms in the water sample is tritium ... 

There are three common ways by which nuclei can approach the region of stability (1) loss of alpha particles (a-decay) (2) loss of beta particles (/3-decay) (3) capture of an orbital electron. We have already encountered the first type of radioactivity, a-decay, in equation (/0). Emission of a helium nucleus, or alpha particle, is a common form of radioactivity among nuclei with charge greater than 82, since it provides a mechanism by which these nuclei can be converted to new nuclei of lower charge and mass which lie in the belt of stability. The actinides, in particular, are very likely to decay in this way. 

Nuclei that have a neutron-proton ratio which is so high that they lie outside the belt of stable nuclei often decay by emission of a negative electron (a beta particle) from the nucleus. This effectively changes a neutron to a proton within the nucleus. Two examples are... 

Neutron activation reactions have also been considered for mine detection. Here a radioactive element is produced in the mine which in the process of decay, emits nuclear radiation, either alpha or beta particles or yrays or two of these or all three in combination. For buried mines the penetrating 7iays are of most in-... 

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