Question 1
Radioactivity is the process by which unstable isotopes of elements disintegrate in the nucleus to release energy in form of gamma rays, beta radiation and alpha radiation. The disintegration occurs as a result of the stability within the cell nucleus. Some isotopes of elements have non-balancing number of the protons as compared to the neutrons, as a result of the lack of balance between the negative and the positive charges in the nucleus; the nucleus becomes unstable and disintegrates. Radioactive radiation was first discovered by Henri Becquerel in 1896 as he was working on X-ray. By then the X-ray had just been discovered by Roentgen. Becquerel realized that even without the exposure to sunlight, uranium salt produced some rays which formed a dark patch on the fluorescent materials. Further study on radioactivity was done by Marie and Pierre Curie. The couples were the first to give it the name “Radioactivity”. They also discovered other radioactive elements such as Radon and Polonium (L'Annunziata, 2012).
During this time, there was very little known about radioactivity. The mystery on the kind of radiation released was still unsolved. When Ernes Rutherford obtained a scholarship at McGill University, in 1898, he started to conduct further research on radiation. His first breakthrough experiment was done by using uranium salt, electroscope and aluminum foils of different thickness. He directed the rays radiated from uranium to a series of aluminum layers from the thinnest to the thickest. He realized that the radiations produced were of penetration ability. By so doing, he was able to isolate two distinct radiations which he named alpha and beta radiations just for convenience (Rutherford, Chadwick & Ellis, 2010). He later used the electroscope to test the charges of the radiations. He realized that the alpha radiation was positively charged why the beta radiation was negatively charged. Rutherford was also able to isolate the radiation which was first observed by Becquerel, and he named it gamma radiation.
In most of his experiments Rutherford required a collaborator who had the required mastery in chemical laboratory experiments. He was therefore joined by Fredrick Soddy by whom they accomplished several discoveries in radiation. Alongside Soddy, Rutherford did several experiments on thorium to establish the process of its decay. They were able to conclude that, upon radiation of thorium, a completely new element with different characteristics was formed. This therefore made them conclude that radiation does not occur in the molecular level of an atom but rather the atomic level thereby altering its atomic characteristics (L'Annunziata, 2012). In addition to his collaborator, Rutherford also had a number of young researchers whom he called the research assistants. They include J.J Thompson, Harriet Brooks and Otto Hahn among others. Their duty was to help in running day-to-day experimental duties while they acquired the knowledge and experience.
Question 2
A mineral ore is a rock with a high concentration of the subject mineral which is extracted and purified to obtain the mineral. The formation of mineral ore involves the process of concentration of mineral. Minerals can be formed in small quantities in different location; but through denudation, weathering and erosion, the get concentrated in one location forming the ore. The Uranium ore is formed in three main ways. The first way is known as magnetic segregation. This is the most common method by which uranium is formed. In this method, uranium is originates from the mantle. During volcanic eruption, it is exposed to the crust where it solidifies. Due to differential rates of cooling, the uranium is concentrated at a given point forming the ore. Due to denudation, the ore can be exposed to the near surface of the crust (Falaise, Volkringer & Loiseau, 2013).
Another method of uranium formation is called diagenesis. Here, the uranium mixes with other elements such as oxygen. During the cooling process, oxygen escapes from the mixture leaving a higher concentration of uranium. Another method is called sedimentation which involves the formation of uranium in beds of water bodies. Uranium is dissolved in the in water and carried away by streams and rivers. When the running water reaches stagnant point such as lakes or oceans, they start to crystalize and deposit the fragment in the sea bed. There are various methods by which uranium are deposited. These forms of deposition will latter determine the method of exploration. The two common methods of Uranium deposits include; Uranium Unconformity Deposits and Uranium Roll Front Deposits (Falaise, Volkringer & Loiseau, 2013).
Uranium Unconformity Deposits are deposits that arise from geologic changes that occur close to Proterozoic Unconformities. They’re shaped as a result of alluviation of uranium and Proterozoic rocs. Attributable to temperature and pressure exerted by the crust, the covering rocks endure metamorphosis. The rocks are then mineralized, abbreviated and faulted. The underlying Proterozoic rocks that are unremarkably younger are metamorphosed. Thermally driven free convection may develop at intervals the sedimentary rock sequence to a lower place a typical thermal gradient, even for a sequence with heterogeneous permeableness succeeding from intercalated fine-grained matter rocks (Mercadier et al. 2011). Figure 1 below shows the formation of Uranium Unconformity Deposits.
Uranium Roll Front Deposits are formed when the ore containing the uranium cuts across the bedrock made of sandstone. These kinds of uranium deposits are formed when uranium is dissolved in water carried by the running current and crystalized at the beds of the water bodies. These uranium ore are easily exposed to the surface because they occur in loose sandstones (Mercadier et al. 2011). They are easier to mine because of their close proximity to the surface. Figure 2 below shows the formation of Uranium Roll Front Deposits.
Figure 1: Uranium Unconformity Deposits (Mercadier et al. 2011)
Figure 2: Uranium Roll Front Deposits (Mercadier et al. 2011)
Question 3
The South Mountain Batholith contains contains various occurrences of uranium deposit. The granatoid rocks of the batholith have been identified as the main sources of the uranium deposits. These deposits are believed to have occurred as a result of mineralization of the dissolved uranium. Uranium in soluble states was believed to have been carried to the region and upon settling, they mineralize and accumulated in the region. The uranium occurs inside the granitoid rocks which have undergone metamorphosis thereby altering the physical structure of the rock. The Millet Brook Deposit is believed to contain the largest amount of uranium within the entire South Mountain Batholith.
Radon gas is a radioactive element which is known to cause respiratory problems. These respiratory problems include lung cancer and bronchitis. It is therefore important that any before any construction is done within a region known to be having radon gas, testing has to be done to ensure that construction is undertaken in areas with the least emission of radon gasses (Toshikuni et al. 2013). The testing can be done using electromagnetic cloud chamber. This apparatus can be used to measure the amount of radon emission by the ground. Measures are taken to ensure that only areas with radon concentration of less than 200 Bp/m3 are selected for radiation. These levels of radon are believed to have insignificant effect on human life.
There are situations where the entire area has radon emission that the least lethal regions have emission of 400 Bp/m3. At these point areas with list emission can be selected for construction. However, measures have to be taken to ensure that the occupants are protected from radon emission. These measures are often undertaken during the construction stages. The radon barrier can be constructed below the floor slab to prevent the gas from reaching the surface. In some cases, radon pumps are constructed in the floor level to pump out the gases away from the building (Toshikuni et al. 2013). This can be done by creating a void below the floor where the gas accumulates then constructing a pipe that directs the gas out of the building.
Reference
Rutherford, E., Chadwick, J., & Ellis, C. D. (2010). Radiations from radioactive substances. Cambridge University Press.
L'Annunziata, M. F. (Ed.). (2012). Handbook of radioactivity analysis. Academic Press.
Falaise, C., Volkringer, C., & Loiseau, T. (2013). Mixed Formate-Dicarboxylate Coordination Polymers with Tetravalent Uranium: Occurrence of Tetranuclear {U4O4} and Hexanuclear {U6O4 (OH) 4} Motifs. Crystal Growth & Design, 13(7), 3225-3231.
Mercadier, J., Cuney, M., Lach, P., Boiron, M. C., Bonhoure, J., Richard, A., & Kister, P. (2011). Origin of uranium deposits revealed by their rare earth element signature. Terra Nova, 23(4), 264-269.
Toshikuni, N., Shiroeda, H., Ozaki, K., Matsue, Y., Minato, T., Nomura, T., & Tsutsumi, M. (2013). Advanced ultrasonography technologies to assess the effects of radiofrequency ablation on hepatocellular carcinoma. Radiology and oncology, 47(3), 224-229.
