Magnesium radioactivity

The existence of bismuthine was first demonstrated by using a radioactive tracer, Bi (8). Acid treatment of a magnesium plate coated with Bi resulted in the hberation of a volatile radioactive compound. In subsequent experiments, magnesium bismuthide [12048-46-3], Mg Bi, was treated with acid the yield, however, was only one part of bismuthine for every 20,000 parts of bismuth dissolved. Attempts to prepare bismuthine by reduction of bismuth trichloride with a borohydride have not been particularly successful. Experimental quantities ate best prepared by disproportionation of either methylbismuthine [66172-95-0], CH Bi, or dimethylbismuthine [14381-45-4], C2H. Bi (7) ... 

Experiments done with radioactive magnesium have established that, for most... 

Elution volume calibrations were performed using radioactive tracers of the rare earth elements and 133Ba, with atomic-absorption or flame-emission analysis of iron, sodium, potassium, calcium, and magnesium. As shown in Fig. 5.14, any barium added to the second columns is eluted at the start of the light rare earth element fraction . To ensure barium removal the sample can be put through the first column again. 

Another isotopic anomaly, discovered in Allende inclusions, concerns magnesium, for which an intrinsically low abundance in these samples makes its isotope ratios sensitive to small effects. Certain of the inclusions show a correlation between 26Mg and 27 Al, indicating an origin of excess 26Mg from radioactive decay of 26 A1 (mean life 1 Myr), the existence of which had previously been postulated as a heat source for meteorite parent bodies (Fig. 3.32). Other short-lived activites that seem to have been alive in the early Solar System are 10Be (mean life 2.2 Myr) from a correlation of 10B with 9Be, and 41Ca (mean life 0.15 Myr) from a correlation of... 

The y particle is emitted virtually instantaneously on the capture of the neutron, and is known as a prompt y - it can be used analytically, in a technique known as prompt gamma neutron activation analysis (PGNAA), but only if such y s can be measured in the reactor during irradiation. Under the conditions normally used it would be lost within the nuclear reactor. In this reaction, no other prompt particle is emitted. The isotope of sodium formed (24Na) is radioactively unstable, decaying by beta emission to the element magnesium (the product nucleus in Figure 2.13), as follows ... 

Swedish chemist Jons Jakob Berzelius Radioactive metal named for Thor, the ancient Scandinavian god of war promising as a future source of nuclear energy makes magnesium alloys heat resistant. 

Since the alpha-ray impacts shattered only a minute proportion of the total number of atoms of boron, aluminum, or magnesium, the chemical identification of the products was extremely difficult. These indefatigable workers, however, accomplished even this. Although it would have been impossible to identify the products simply by ordinary chemical means, the Joliots were able to take advantage of the radioactive nature of the products formed. Since they had good reason to believe that the boron atom had captured a helion and ejected a neutron and that the new element was therefore probably an isotope of nitrogen, they heated some bombarded boron nitride with caustic soda and found that the liberated... 

There are a number of possible sensor options for a y-ray spectrometer. These include a germanium sensor or scintillators made of various synthetic materials. Elements that are routinely analyzed with y-rays include silicon, iron, titanium, magnesium, calcium, and aluminum, plus the radioactive elements potassium and thorium (uranium concentrations are usually too low). 

The production of artificially produced radioactive elements dales back to the early work of Rutherford in 1919 when it was found that alpha particles reacted with nitrogen atoms to yield protons and oxygen atoms. Curie and Joliot found (1933) that when boron, magnesium, or aluminum were bombarded with alpha particles from polonium, the elements would emit neutrons, protons, and positrons. They also found that upon cessation... 

Fredenc and Irene Joliot-Cune found in 1933 that boron, magnesium, or aluminum, when bombarded with a-particles from polonium, emit neutrons, proton, and positrons, and that when the source of bombarding particles was removed, the emission of protons and neutrons ceased, but that of positrons continued. The targets remained radioactive, and the emission of radiation fell off exponentially just as it would for a naturally occurring radioclcmcnl. The results of this work may be stated in two equations as follows ... 

TRANSMUTATION. The natural or artificial transformation of atoms of one element into atoms of a different element as the result of a nuclear reaction. The reaction may be one in which two nuclei interact, as in the formation of oxygen from nitrogen and helium nuclei (/3-particles), or one in which a nucleus reacts widi an elementary particle such as a neutron or proton. Thus, a sodium atom and a proton form a magnesium atom. Radioactive decay, e.g., of uranium, can be regarded as a type of transmutation. The first transmutation was performed bv the English physicist Rutherford in 1919. 

Group II consists of the five metals beryllium, magnesium, calcium, strontium and barium, and the radioactive element radium. Magnesium and calcium are generally available for use in school. These metals have the following properties. 

This group contains the elements beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra). After the alkali metals, they are the second most active metals. Their electron configurations end with ns2. They become positive two charged ions by giving of their two valence electrons in chemical reactions. At room temperature, they occur in a monoatomic structure and they are solid at room temperature. Radium, a solid element, is the only radioactive member of this group. 

The construction and application work on the linear model of sorption has important results. First, the distribution coefficients of the different minerals for radioactive ions in very low concentrations can be determined. The minerals with similar structure obviously have similar distribution coefficients because of the similar sorption mechanism. The differences are the results of a specific property of the minerals for example, the presence of iron of magnesium in carbonates has a significant effect on the sorption of the cesium ion. 

Samples (156) were taken from 54 reference lithic pieces that represented five rock types. These samples were analyzed at the SLOWPOKE Reactor Facility of the University of Toronto. They were irradiated for 1 min at 2 kW, or for 1 or 2 min at 5 kW (depending on their radioactivity level in preliminary tests). Upon removal from the reactor, the samples, which weighed between 0.1 and 0.3 g, were left to decay for 18 min and were counted for 5 min with a Ge(Li) y-ray detector coupled to a multichannel analyzer. Trace element concentrations were calculated with the comparator method (7). The 15 elements examined were barium, titanium, sodium, aluminum, potassium, manganese, calcium, uranium, dysprosium, strontium, bromine, vanadium, chlorine, magnesium, and silicon. The first seven of these elements were the most useful in the differentiation of major rock types. 

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