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Working with Atomic Mass and Nuclear Mass
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
Assume that the actual measured mass of bismuth-209 can be calculated as 3.470 × 10−25 kg to four significant figures. As a practice exercise, calculate the mass loss when the nuclear particles of bismuth-209 bind together to form one nucleus; that is, calculate the mass difference between the calculated sum of the independent nuclear particles for bismuth-209 and the actual measured mass given. The sum of independent particles for bismuth-209 was calculated previously at the beginning of the chapter.Use your results from part (a) to calculate the energy released when one nucleus of bismuth-209 is formed; use Einstein’s equation.Use your results from part (b) to calculate the energy released when one gram of bismuth-209 nuclei is formed; first calculate the number of atoms in one gram.Use the value that combustion of one gallon of gasoline produces about 2.4 × 108 Joules of energy. Determine the number of gallons of gasoline that must be burned to equal the amount of energy released by formation of one gram of bismuth-209 nuclei; use your answer from part (c).
Spies, Subterfuge, Missions and Murder
Published in Alan Perkins, Life and Death Rays, 2021
Polonium-210 is considered to be one of the most toxic naturally occurring radionuclides found on earth and has the potential to affect human health, due to its wide environmental distribution. Human radiation exposure from polonium results from both ingestion and inhalation. It is a highly toxic radioactive heavy metal with a physical half-life of 138 days and decays to stable lead-206 giving off 5.3 MeV alpha particles that have a range of less than a millimetre in tissue. It occurs naturally in the earth’s crust and was the first element to be discovered by Marie and Pierre Curie as they worked to discover the nature of radioactivity in pitchblende ore in 1898. Artificial production normally requires a reactor for the bombardment of bismuth-209 with neutrons. It has been used in devices that eliminate static and dust, since the alpha particles ionise the air, neutralising static electricity. This has applications for industrial processes such as paper rolling, the production of plastic sheeting, spinning synthetic fibres and spray-painting work. Polonium-210 has also been also used in the fibres of brushes to remove dust from photographic film and camera lenses. Large amounts of polonium-210 generate heat as the atoms decay, leading to use in thermoelectric power generators and heaters for a range of military and space applications. The Russian lunar landers used these devices during space missions to warm the operational instruments at night. An ingenious application was considered by the Firestone Tyre and Rubber Company who held a patent for the use polonium-210 incorporated in the electrodes of automobile spark plugs (Figure 12.7). The emission of alpha particles was considered to result in a more responsive and reliable spark during engine ignition; however, this was never adopted for commercial long-term use.
Applying a multiscale systems biology approach to study the effect of chronic low-dose exposure to uranium in rat kidneys
Published in International Journal of Radiation Biology, 2019
Stéphane Grison, Dimitri Kereselidze, David Cohen, Céline Gloaguen, Christelle Elie, Philippe Lestaevel, Audrey Legendre, Line Manens, Baninia Habchi, Mohamed Amine Benadjaoud, Georges Tarlet, Fabien Milliat, Jean-Charles Martin, Jean-Marc Lobaccaro, Maâmar Souidi
To measure the NU burden in kidneys, samples were prepared by adding 8 mL of ultrapure nitric acid (69%) and 2 mL of hydrogen peroxide (30%), and then mineralized in a 1000 W microwave (Ethos Touch, Milestone Microwave Laboratory Systems, (Sorisole, Italy) with an increasing rate of 9 degrees per minute until a temperature of 180 °C that was maintained for 10 min. Samples were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS; XSERIES 2, ThermoElectron, France). Experimental conditions were optimized by using a multi-element standard solution (ThermoElectron, France), and bismuth 209 was added to all samples as an internal standard at 1 µg L−1. A calibration curve was calculated based on a standard solution at 1000 mg L−1 in 2% nitric acid freshly diluted to obtain (0, 0.001, 0.005, 0.01, 0.1, 0.5, and 1 µg L−1) in 2% nitric acid. A linear relation-count number (iU) = f([iU]) was calculated for each isotope, i = [235;238] with [iU] equal to the isotope concentration in µg L−1. The ICP-MS limit of detection for uranium is 1 ng L−1.
Low dose of uranium induces multigenerational epigenetic effects in rat kidney
Published in International Journal of Radiation Biology, 2018
Stéphane Grison, Ghada Elmhiri, Céline Gloaguen, Christelle Elie, Dimitri Kereselidze, Karine Tack, Philippe Lestaevel, Audrey Legendre, Line Manens, Mohamed Amine Benadjaoud, Jean-Marc Lobaccaro, Maâmar Souidi
Kidney samples were prepared by adding 8 mL of ultrapure 69% nitric acid to 2 mL of 30% hydrogen peroxide. They were mineralized in a 1000 W microwave (Ethos Touch, Milestone Microwave Laboratory Systems, Italy) with a 20-min ramp to 180 °C then 10 min at 180 °C. Samples were analyzed by ICP-MS (XSERIES 2, ThermoElectron, France). A multi-element standard solution (ThermoElectron, France) was used to optimize experimental conditions and apparatus parameters to obtain the best signal/noise ratio for uranium 238. In all solutions likely to be analyzed (biological samples or calibration solutions), bismuth 209 was added as an internal standard at 1 μg L−1. Seven standard solutions for the calibration curve (0, 0.001, 0.005, 0.01, 0.1, 0.5, and 1 μg L−1) were freshly prepared by dilution of a standard solution of 1000 mg L−1 uranium in 2% nitric acid (Claritas PPT, Horiba Scientific). A linear relation—count number (iU) = f([iU]) was calculated for each isotope, i = [235;238] with [iU] equal to the isotope concentration in μg L−1. Isotopy and dosage reliability were regularly verified with standard solutions. The ICP-MS limit of detection for uranium is 1 ng L−1.