Victoria NewburyPhysics 133 Lab MLHasbrouck 212Due Date: 4/10/14Radioactive decay; alpha, beta, and gamma AbstractRadioactive decay occurs as a result of an unstable nucleus with an excess of neutrons or protons. There are three types with their own unique characteristics and formulas, they include alpha, beta, and gamma decay. Another important concept during this lab was half-life, which uses a formula to calculate the remaining atoms of a substance after a certain period of time.Questions & Answers1. Provide data for parts 6.5.2 and 6.5.3. Determine whether each data point lies within yourconfidence interval (i.e. is it inside the NB +/- NB range?). (2 points)a. 6.5.2: NB counts = 96 total ; 96/5 minutes = 19.2 counts/minsb. 6.5.3:Trial Background/min Inside the confidence interval (between 14.8 and 23.5) (NB +/- NB)1 19 Yes2 13 No3 24 No4 17 Yes5 24 No6 10 No7 19 Yes8 23 Yes9 21 Yes10 21 Yes2. Consider three decays of equal particle energy: one each of alpha, beta, and gamma. Which decay based on your results of 6.5.4 has the most penetrating power? Which decayis the most hazardous to bystanders and why do you think so? (2 points)a. The decay with the most penetrating power based on my results of 6.5.4 is alpha rays, without anything on them they reached levels of 14,035 counts/2 minutes. The decay that is most hazardous to bystanders is gamma rays because they are high-energy photons that can be absorbed by molecules in the body. Once in the body when can disrupt bonds, strip elections, or convert to heat. These are all bad for living things.3. Calculate the half-life for In-116 using the data given to you from computer printouts. Attach the copies of computer printouts given to you in the class. (2 points).a. The half-life for In-116 is 2500 seconds. This was calculated using the formula Nt= N0(1/2)t/(t1/2) also using the graph to see the amount of time it takes for half of In – 116 to decay. Refer to the attached sheet to see how this was found.4. A sample of 2.3 x 1010 atoms that decay by alpha emission has a half-life of 120 minutes. How many alpha particles are emitted between t = 60 min and t = 240 min? (2 points)a. Particles at t = 60i. Nt= N0(1/2)t/(t1/2) = 2.3e10(1/2)60/120ii. Nt = 1.626e10 atomsb. Particles at t = 240 minsi. Nt= N0(1/2)t/(t1/2) = 2.3e10(1/2)240/120ii. Nt = 5.75e9c. Alpha particles emitted between t = 60 and t = 240 = 1.051e10 particles.5. Use the three examples in 5.5.4 to explain what alpha decay, beta decay, and gamma decay are. Write down the reaction expressions for the three decay events. (2 points)a. Alpha decay occurs when a nucleus emits an alpha particle and changes into an atom with a mass number 4 or less and atomic number of 2. The reaction expression for the decay event is 238 92 U 234 90Th + 4 2 He + energy.b. Beta decay is when a beta particle is emitted from a nucleus and allows the atom to obtain the optimal ratio of protons and neutrons. The reaction expression for the decay event is 3 1 H 3 2 He + + v + energy.c. Gamma decay is a type of radioactivity in which an unstable atomic nucleus releases energy through gamma cells and this creates gamma rays. The reaction expression for the decay event is 60 27 CO 6028Ni* + B- + v + energy and 60 28 Ni* 6028Ni + + energy6. Can you think of two examples that radioactivity is used in real life? Give a brief explanation on how your examples related with radioactivity (no more than 5 lines for each). (2 points).a. Two examples that use radioactivity in real life involve the treatment of cancer and as a tracer for medical diagnosis. Certain isotopes are used and the radioactivity is more likely to kill the mutated cancer cells instead of the regular healthy cells. As a tracer for medical diagnosis, radiation is used when a person has bone, liver, kidney, or digestive system problems. The tracer is put in as isotope Technetium 99 or Thallium 201 for heart diagnosis.ConclusionRadioactivity is an important tool involved in many daily occurrences. It is important to observe safety measures when handling certain radiation as it can be dangerous if you are exposed to it for long periods of
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