...Unit 5 WA1 Kim Phillips Radioactive decay rates are normally stated in terms of their half-lives, and the half-life of a given nuclear species is related to its radiation risk. The different types of radioactivity lead to different decay paths which transmute the nuclei into other chemical elements. Examining the amounts of the decay products makes possible radioactive dating. Though the most massive and most energetic of radioactive emissions, the alpha particle is the shortest in range because of its strong interaction with matter. The electromagnetic gamma ray is extremely penetrating, even penetrating considerable thicknesses of concrete. The electron of beta radioactivity strongly interacts with matter and has a short range. The reason alpha decay occurs is because the nucleus has too many protons which cause excessive repulsion. In an attempt to reduce the repulsion, a Helium nucleus is emitted. The way it works is that the Helium nuclei are in constant collision with the walls of the nucleus and because of its energy and mass; there exists a nonzero probability of transmission. That is, an alpha particle will tunnel out of the nucleus. Beta decay occurs when the neutron to proton ratio is too great in the nucleus and causes instability. In basic beta decay, a neutron is turned into a proton and an electron. The electron is then emitted. Gamma decay occurs because the nucleus is at too high an energy. The nucleus falls down to a lower energy state and, in the process, emits...
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...Radioactive Isotopes Introduction: - Radioactive isotopes are kind of isotopes, which have an unstable nuclide and react in assorted ways, they are derived from isotopes that also hold an unstable nucleus but they do not react as radioisotopes do. These factors are categorized by the extra energy which is present in them and which would be used to react and produce some other particle. The reaction, which would result in various emissions of Gama, rays, alpha particles, beta particles. The reaction, which causes these emissions, is called radioactive decay (Radioactivity). The discharge of the radioactive decay is harmful in various ways, only due to the progress in technology now these disadvantages have been converted to advantages and now radioisotopes are used in several facial expressions, which also let in various medical aspects, which would be compensated in the report. The concept of Radioactivity was found by a French physicist, Antoine Henri Becquerel. As most of the discoveries, this also was by a very honest observation and accidental. During the research of phosphorescent materials (The elements which glow in black). Studying Uranium for his research, he kept the uranium on the photographic film, it was a routine for him to hold it under the sunlight for some days and then examine it later. On a cloudy day, he kept the film and the uranium inside. Later on some days he took an observation when he watched the video, the image of the uranium appeared in the film...
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...Radium City was home to a company known for aiding in the horrible death of several women. The company hired women to paint numbers on watch dials with a paint mixed with radium. These girls were unaware of the dangers they would encounter each day while working for this company. This essay will contain information explaining what radium is and how it can be harmful to the human body. Also leading to the discussion of how the Radium Girls sustained radiation exposure and how they could have reduced the amount of radiation exposure received while painting watch dials. Radium is a known isotope from the periodic table of elements that naturally occur throughout the world. (ATSDR,2015). Radium is highly radioactive and eventually will lead to harmful effects to the human body. The determining factors that aid in...
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...means more than it's literally meaning, of the poem and the whole meaning of it really. The author Udiah I don't think is speaking directly, I think the poem is in third person and he makes it seem as if the planets are telling the story themselves or some foreign force. The situation in the poem is the amount of force in outer space that it takes for an old star to die and new one to come about. Although the poem is very vast and interesting there are some references that need explaining such as how the birth of a star happens exactly, I don't think an average reader would understand necessarily the science behind it. Some of the words I looked up helped me find better meaning in the poem, Nuclear Fission a nuclear reaction of a radioactive decay process in which the nucleus of a particle splits into smaller parts. This particular word is used at the beginning of the poem, means to me that the red giant has exhausted it's supply of hydrogen and can no longer hold it all in anymore, there forth letting go. The poem develops on an Idea, an idea of a new born star. I think that Udiah must have some interest in outer space and the wonders of it. But the ultimate meaning of the poem is not outer space it is simply the meaning of new life, and the great effort it takes to bring that fourth. The 11th line in the poem says "And then burst forth in a great cosmic cry" this comparison between a new borns...
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...color: 24 throws Two side color: 19 throws Three-side color: 17 throws 4. In which of these hypothetical substance would be the most radioactive? The substance that will decay much faster is the third substance represented by black on the three sides of the cube. According to my tabulation, the curve for the third substance appeared much steeper and at the seventeen throw no cubes were remaining. 5. How might you simulate the radioactive decay of a substance that decays into second substance that also decays? First, the substance always decays because the initial stage is not stable. Lack of stability forces the substance to decay into a second substance with a loss of either an electron, energy or a proton. If the second substance is not stable, it will disintegrate into the third substance. This process might continue until the substance gain stability. 6. Is it possible to estimate the half-life of a substance in a single throw? How accurate might this estimate be? Yes, this is because the first throw might reduce the number of cubes by half especially if the substance being simulated is highly radioactive. This estimation may not be accurate since the practical depend on probability. 7. Are your lines in the graph for step 8 fairly straight or do they curve? Do these lines correspond to a constant or non-constant rate of decay? The lines in the graph are curved....
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...Investigating the Concept of Half-Life in Radioactive Decay Using Coins. Abstract The main aim of the two experiments is to verify that 50% of coins will decay (heads-up) in the first throw. In the first experiment, 100 coins (tails-up) will be placed in a box with a cover then shaken thoroughly. Coins with heads –up will be removed to represent the decayed atom. It will be realized that 52% of the coins will decay within the first throw. Similarly, the second experiment will test the same concept. Eight coins will be used for the second experiment. Eight coins will be thrown for each decay cycle. The total numbers of pennies decayed and total number of pennies thrown will be calculated. It will be realized that 50.25% of the pennies will decay during the first throw. The second experiment will also test the average value for three half-lives. It will be noted that the average value for three half-lives is 6. Data will be represented in form bar graphs, tables as well as plotted curves. Introduction Radioactivity is a spontaneous and self-disruptive process that involves emission of radiation or particles as a result of disintegration of some nuclides (Michael, 2). Half-life refers to the time taken for a substance to decay by half its original value (Jha, 4). In this experiment, the removal of the coins represents the radioactive decay of the nucleus of an atom. Serway, et al (482) states that the number N of the radioactive nucleus of the same kind that are found...
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...of nuclear medicine should continue in the future. Nuclear medicine uses radioisotopes for both treatment and diagnostic purposes. Radioactive tracer molecules are emitted to produce images, which can then be used to examine and diagnose a patient to provide further treatment. Radiation is also used to treat cancer by eradicating cancerous cells. Further advancements of nuclear technology is conducted in trials and is progressing to hopefully treat different types of disease, all using radionuclides. Radionuclides are chemical elements that are radioactive with short half-lives. Although they can be found in nature, all radionuclides used in nuclear...
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...Radioactive Isotopes: Their uses in health care Radioactive Isotopes are atoms of the same element with different masses. They have unstable nuclei and get rid of excess energy by releasing radiation in the form of alpha, beta, and gamma rays. Some radioactive isotopes include: Carbon-11, Copper-64, Fluorine-18, and Oxygen-15. These isotopes have different properties and are used to detect and cure health issues through the use of radioactive pharmaceuticals such as PET scans and radiation therapy. PET scans, or Positron Emission Tomography scans, are used to determine what kind of diseases may reside in the body; this is done by introducing a positron- emitting radionuclide, which gathers in the target tissue. As this radionuclide decays it emits a positron, which combines with a nearby electron; this in turn results in the simultaneous emission of two identifiable gamma rays in opposite directions (Radioisotopes in Medicine, 2013). These gamma rays are then detected by the use of a PET camera. Some radioactive isotopes; such as Carbon-11, Nitrogen-13, Oxygen-15, Fluorine-18, and Copper-64, are used in PET scans as positron emitters. PET’s are used mostly in the field of oncology (the study of tumors and cancers) and most commonly use the isotope Fluorine-18 as the tracer. Fluorine-18 is most often used because of its half- life, which is approximately 110 minutes. This is certainly a lot longer than the half-lives of Carbon-11, Nitrogen-13, or Oxygen-15 which have...
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...radon, a noble gas. Frederick is a German chemist from the 19th century that studied radiums decay chain. There were a lot of names for radon before 1923 when it officially became radon, like niton a Latin word which means shining, another name for it was theorem emanation because the gas was discovered in theorem . Radon is a weak yet deadly gas that should never be underestimated. Radon was discovered in 1900 by a scientist named Friedrich Ernst Dorn but it was not him that did the experiments. It was Robert B. Owens and Ernest Rutherford who did them at McGill University in Montreal. What they were originally doing was measuring the radiation levels of theorem oxide. But they noticed that it contained a radioactive gas that could be radioactive on its own for several minutes. They first called it theorem emanation then the name changed to radon in 1923. Radon till this day is still collected through the decay chain of radium. Radon is a very radioactive gas it is also colorless and odorless at room temperature. A common form of radons decay is alpha decay, alpha decay is not known to be a big radiological hazard since alpha particles that are produced from the process can be easily stopped. But although radon seems almost harmless it is still a gas and can be easily inhaled into living tissue where the body is exposed directly to the radiation. Even though Radon is radioactive its half-life is relatively short which is a good thing if any of it leaks out, radon can also...
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...is important for people to understand that within the nucleus of an atom resides tremendous capability. It is up to humans to unlock that potential and create something in the best interest of society. While it is understood that the nuclear decay process can wreak havoc on humanity, harnessing the nucleus of radioactive isotopes for the welfare of civilization can be accomplished through nuclear power plants, nuclear medicine, and nuclear preservation of food, we may fully be able to use these nuclei to humanity’s advantage. Nuclear power plants are one way that humans have controlled nature to benefit them. Nuclear power is the use of nuclear reactions that release nuclear energy to create heat. Steam turbines are then used to make energy from the heat. The elements in the Actinide series of the periodic table are mainly used for nuclear fission reactions. Nuclear fission power plants produce 11% of the world’s electricity, less than what hydro-electric stations produce. Along with other sustainable energy sources, nuclear fission is a low carbon power generation method of making energy, which means that is renewable and doesn’t create much air pollution. General nuclear medicine is another way humanity has harnessed nuclear decay. Nuclear medicine is a branch of medical imaging that uses small amounts of...
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...Caesium is a type of metal that can be radioactive or nonradioactive, in other words it can be stable or unstable. Caesium 137 is an isotope of Caesium, it is radioactive, or unstable. It is a very familiar and common radioactive isotope, for example it is more environmentally compelling or important than another isotope of Caesium like Caesium 134. Caesium 137 along with several other radioactive isotopes were discovered in the 1930’s by Glenn T. Seaborg. Although Caesium was first discovered as non radioactive in water in Germany by two germans named Gustav Kirchhoff and Robert Bunsen (Cesium, Radiation Protection). Before going into the science behind Caesium 137 I will explain what an isotope and a radioisotope is. All elements naturally occur as isotopes, they are basically atoms with a different amount of neutrons. For example, Caesium 137 and Caesium 136 are both isotopes of the element Caesium. We can tell these isotopes apart by naming them by their total mass numbers. The total mass numbers are calculated by adding the number of protons with the amount of neutrons. Each isotope has a different mass number, Caesium 137 has 82 neutrons and 55 protons, therefore it is labelled Caesium 137, as 82 added by 55 equals 137. The mass numbers of isotopes also indicate the atomic weight of the isotopes, Caesium 137 is 137 atomic mass units or 137 u. The atomic mass of the elements are decided by the mass number of their average isotope. Regular Isotopes always maintain...
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...radiation from the decay of the tracer in a region of interest (ROI) in the images. The kinetics of the tracer from the vasculature to target tissue is often quantified by rate constants using compartmental modeling. A compartment is defined as a volume where a tracer can be uniformly distributed. These compartments represent physical structures such as a blood vessel and target tissue, or more abstract such as groups of cells which metabolize a tracer in different ways. Rate constants describe the concentration gradient of the tracer between compartments. For simplicity, many compartmental models assume first-order rate constants. The input function describes the evolution of the tracer in the blood after injection, and the tissue response measures the activity of the tracer in the tissue of interest during uptake. Contrast between different tissues arises from the number of radioactive emissions from the tracer which is proportional to tracer concentration. Thus a tissue with higher concentrations of the tracer will produce a higher signal relative to a tissue with lower concentrations of the tracer. Background activity adds noise and thus compromises these measurements. After corrections to the signal accounting for attenuation and decay of the tracer, relative concentrations of the tracer in different tissues can be calculated to produce contrast. Standard uptake value (SUV) is a common “contrast” measurement for tumors and is defined as the ratio of the decay-corrected activity...
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...is converted to a proton, so the mass number remains the same while the atomic number increases by one unit. And gamma rays consist high-energy photons with a relatively short wavelength (0.0005 ~ 0.1 nm). The particles emitted in radioactive decay processes have high kinetic energy, which is enough to ionize an atom or a molecule; especially photons, which can ionize atoms and molecules through the photoelectric effect and Compton scattering. And if the radiation is sufficiently intense, the speed of destroying molecules is faster than coping them, which can cause harmful chemical damages to healthy cells and even to DNA. But on the other hand, the damaging effects of radiation can used to kill the rapidly growing cancerous cells. Radiotherapists can localize the source of damage and minimize the effect on the surrounding tissue. For example, external beam therapy is used to direct towards the affected part...
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...Chapter 1/Lesson 1 Key Terms: archaeology | The study of the human past, combining the themes of time and change. | culture | A uniquely human means of nonbiological adaptation; a repertoire of learned behaviors for coping with the physical and social environments | artifact | Any object or item created or modified by human action. | evolution | The process of change over time resulting from shifting conditions of the physical and cultural environments, involving mechanisms of mutation and natural selection. | fieldwork | The search for archaeological sites in the landscape through surveys and excavations. | site | The accumulation of artifacts and/or ecofacts, representing a place where people lived or carried out certain activities | survey | A systematic search of the landscape for artifacts and sites on the ground through aerial photography, field walking, soil analysis, and geophysical prospecting. | shell midden | A mound of shells accumulated from human collection, consumption, and disposal; a dump of shells from oysters, clams, mussels, or other species found along coasts and rivers, usually dating to the Holocene. | excavation | The exposure and recording of buried materials from the past. | ethnography | The study of human cultures through firsthand observation. | economy | The management and organization of the affairs of a group, community, or establishment to ensure their survival and productivity. | technology |...
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...Historical Use of Radiotracers The principle of radionuclides to track and follow physical, chemical and biological processes has achieved widespread use since their earliest discovery. The father of biological radiochemistry, George de Hevesy, was the first to use a radioactive isotope of lead in bone studies, closely followed by R. H. Stevens injecting radium chloride intravenously to study malignant lymphoma[14]. Artificially generated radioisotopes revolutionised the use of radiotracers in biomedical study[2]. Iodine radiosotopes have been used since the early 1940s to examine the thyroid gland[15]. Biodistribution studies of radiotracers in a subject began with the work of Cassen (rectilinear scanner)[16,17] and of the gamma scintillation...
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