Radioactive decay, natural

The half-lives of the elements vary widely, as shown in Table 3.2. Some isotopes, nitrogen-14 for example, are stable and experience no natural radioactive decay. However, bombarding even a stable element with energetic alpha rays can cause transmutation. Rutherford discovered the proton when he created hydrogen from a stable isotope of nitrogen. 

Transmutation The conversion of one element into another by natural radioactive decay or by bombarding it with radiation. 

He is found in natural gas deposits principally because alpha particles are produced during natural radioactive decay processes. These alpha particles are 4 He nuclei they obtain two electrons from the surrounding material to become helium atoms. This gaseous helium then accumulates with the natural gas trapped beneath the earth. Although other noble gases are produced by radioactive decay—notably 40 Ar—they are not produced in the large quantities that helium is. 

The following particles are involved in natural radioactive decay. 

Many of the heavy elements in the three natural radioactive decay chains also decay by -emission. 

Fig. 1.2 The three natural radioactive decay series as understood by F. Soddy and K. Fajans in the period 1913-1920...

The stage was now set for the 1913 papers published independently by Fajans (1913b) and by Soddy (1913a). The paper by Fajans was published a couple of weeks prior to that by Soddy. Soddy has stated that he had not seen the Fajans paper at the time when he wrote his paper. Both papers try to generalize experimental observations on the chemical identities of decay products in the three natural radioactive decay series. 

Most of the known chemistry of polonium is based on the naturally occurring radioactive isotope polonium-210, which is a natural radioactive decay by-product of the uranium decay series. Its melting point is 254°C, its boiling point is 962°C, and its density is 9.32g/cm. ... 

As thorium undergoes natural radioactive decay, a number of products, including gases, are emitted. These decay products are extremely dangerous radioactive poisons if inhaled or ingested. 

For very many years, the alchemist s dream of changing base metals into gold was ridiculed even by the most reputable of scientists. Although it was known that the nuclei of certain atoms undergo alteration in the course of natural radioactive decay, researchers inability to exercise any control over the nature or rate of these spontaneous decompositions probably did much to foster the belief that the nucleus of the atom was inviolate. However, in the year 1919 the English physicist Ernest Rutherford accomplished the first transmutation of an element, and this notable discovery was quickly followed by other equally significant developments. 

Yatsevich, I., Honda, M. (1997) Production of nucleogenic neon in the Earth from natural radioactive decay. J. Geophys. Res., B102(5), 10291-8. 

The element francium is formed in the natural radioactive decay series and in nuclear reactions. All its isotopes are radioactive with short half-lives. The ion behaves as would be expected from its position in the group. 

Ultratraces of Po are distributed worldwide as nuclear contamination in the environment, bnt °Po also occurs as a natural radioactive decay product in the decay chain of and can be analyzed by a-spectrometry. In spite of the short Po half life (tj j = 138days), traces can also be detected after careful separation (due to isobaric interference with Pb in nuclear samples and environmental materials) using advanced mass spectrometric techniques such as CE-ICP-MS or AMS as demonstrated in references" " ... 

Which of the following reactions represent natural radioactive decay, and which are artificially induced ... 

Daniell cell (17.1) A cell with zinc and copper electrodes, daughter isotope (21.1) The large product of a natural radioactive decay event. 

Uranium undergoes natural radioactive decay, emitting an alpha particle, or helium nucleus, to become thorium-234. The thorium emits an electron and becomes protactinium. This nucleus continues to decay through a series of lighter and lighter isotopes of various elements until it finally reaches a stable state in the form of lead. The entire process involves fourteen distinct steps. 

Uranium-238 is the parent of a natural radioactive decay series that can be used to determine the ages of rocks. 

Table 2.1 The natural radioactive decay series from to 82Pb (see Figure 2.3) (yr = year d = day min = minute s = second).

Because all long natural radioactive decay series end up in lead, Pb made from different ores contain slightly different isotopic abundances of lead isotopes. An imusual use of this fact was made by Andrasko et. al. to identify smears and fragments from lead bullets used in a homicide case, so that the suspect could be bound to the case, as the isotopic composition of lead bullets can be identified not only by manufacturer but also by manufacturing date. 

We use X to indicate any element defined by its nuclear charge, Z and Z-2 in this equation. Examples are given in Ch. 1, and can be found e.g. in the natural radioactive decay series, see next chapter. 

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