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Published byXzavier Isaacs Modified over 9 years ago
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Good Day! 4/11/2017 Discuss the uses of Radioactive Isotopes.
Starter: So why do we create all of these elements if many are radioactive? (what does radioactive mean?) Today we are going to… Discuss the uses of Radioactive Isotopes. Answer: We create them because surprisingly they are very useful and today we will be exploring their uses.
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Instructions We will now split up into groups, and each group will be responsible for one use of Radioactive Isotopes. In your groups you need to explain how Radioactive Isotopes are used and do this in about one sentence. Things to include which isotopes are used? (be specific like Carbon-12). How are they used (what do they do?)
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Instructions We will now split up half of you will be researching your area of use and the other half will be taking notes from the powerpoint on nuclear decay.
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Uses of Radioactive Isotopes
1. Dating of Fossils 2. Chemical Tracers 3. Industrial Uses 4. Medicine 5. Nuclear Power
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Dating of Fossils Carbon-14 and 12 are absorbed and 14 decays into Nitrogen 14, the use the ratio to determine the age of an organism.
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Chemical Tracers They use the radioactive signal from the isotopes. They use Iodine-131 to determine the functionality of the thyroid.
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Industrial Uses Smoke detectors use Americium-241.
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Medicine Used to treat cancer.
Techtium-99 is used to destroy harmful cells
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Nuclear Power They use uranium-235
The thermal energy released in nuclear fission, is used to generate electricity.
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Good Day! 4/11/2017 Starter: Why is it that we use these isotopes? (what is it that they do that make them so useful?) Today we are going to… Continue discussing the many uses of radioactive isotopes and the reactions that cause them. Answer: They give off a radio signal so they are often like a beacon or a tracking signal.
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Harmful effects Radiation penetrates living tissue and can damage the tissue or cause disease. All living organisms must be protected from the radiation until the the isotopes have decayed.
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Link to Audio "Their Shining Lives" tells the story of young women who were exposed to toxic levels of radiation, and who took their employer to court in the 1920s. (Photo by Scott Pakudaitis) Link to Radium
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Alpha Decay During alpha decay, a nucleus loses an alpha particle, which consists of two protons and two neutrons.
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Beta Decay During beta decay, a neutron inside an unstable nucleus changes into a beta particle and a proton.
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Gamma Decay Gamma radiation has no charge and does not cause a change in either the atomic mass or the atomic number.
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Types of Radioactive Decay
The three types of nuclear radiation were named based on how easily each one could be blocked. Alpha, beta, and gamma are the first three letters of the Greek alphabet.
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Transmutation 18
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Table – Beta Particles
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Beta Decay
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18 Table – Gamma Rays
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Half Life 8 H-3’s 4 H-3’s & He-3’s 2 H-3’s 6 He-3’s
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Half Life The half life of a radioactive isotope is the amount of time it takes for ½ of the isotopes to decay.
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Radioactive Isotopes The half-lives of radioactive isotopes range from a fraction of a second to billions of years.
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6. How do we know how long the material will be around?
It is all about the halflife of the element. The half life is the amount of time it takes for half of the atoms in a sample to decay. Link
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Using Radioactive Isotopes
Tracers are radioactive isotopes that can be followed through the steps of a chemical reaction or industrial process.
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Smoke Detector
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Using Nuclear Reactions in Medicine
Scientists can find one molecule in a large group of molecules if it is sending them a signal. If it has a radioactive atom in it, it can be found easily in a large group of molecules, or even in a living organism.
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Using Nuclear Reactions in Medicine
When a radioisotope is used to find or keep track of molecules in an organism, it is called a tracer. Scientists can use tracers to follow where a particular molecule goes in your body or to study how a particular organ functions.
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Using Nuclear Reactions in Medicine
Examples of tracers include carbon-11, iodine-131, and sodium-24. These three radioisotopes are useful tracers because they are important in certain body processes. As a result, they accumulate inside the organism being studied.
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Iodine Tracers in the Tyhroid
Because the element iodine accumulates in the thyroid, the radioisotope iodine-131 can be used to diagnose thyroid problems. As iodine-131 atoms are absorbed by the thyroid, their nuclei decay, emitting beta particles and gamma rays.
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Iodine Tracers in the Tyhroid
The beta particles are absorbed by the surrounding tissues, but the gamma rays penetrate the skin. The emitted gamma rays can be detected and used to determine whether the thyroid is healthy.
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Iodine Tracers in the Tyhroid
If the detected radiation is not intense, then the thyroid has not properly absorbed the iodine-131 and is not functioning properly.
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Treating Cancer with Radioactivity
Radiation can be used to stop some types of cancerous cells from growing. Remember that the radiation that is given off during nuclear decay is strong enough to ionize nearby atoms. If a source of radiation is placed near cancer cells, atoms in the cells can be ionized.
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Treating Cancer with Radioactivity
If the ionized atoms are in a critical molecule, such as the DNA or RNA of a cancer cell, then the molecule might no longer function properly. The cell then could die or stop growing.
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Treating Cancer with Radioactivity
When possible, a radioactive isotope such as gold-198 or iridium-192 is implanted within or near the tumor. Typically, an intense beam of gamma rays from the decay of cobalt-60 is focused on the tumor for a short period of time. The gamma rays pass through the body and into the tumor.
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Treating Cancer with Radioactivity
Cancer cells grow quickly, they are more susceptible to absorbing radiation and being damaged than healthy cells are. However, other cells in the body that grow quickly also are damaged, which is why cancer patients who have radiation therapy sometimes experience severe side effects.
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What process is being illustrated here?
Question 3 What process is being illustrated here? A. chain reaction B. nuclear fusion C. nuclear fission D. semiconducting
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Answer The answer is C. Nuclear fusion occurs when two nuclei combine to form one nucleus.
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Question 4 A series of repeated fission reactions is called a(n) __________. A. chain reaction B. critical mass C. meltdown D. uncontrolled reaction
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Answer The answer is A. If the chain reaction is uncontrolled, an large amount of energy is released in an instant. Chain reactions are controlled by adding materials that absorb neutrons.
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Question 5 What is required in order for a radioisotope to be useful as tracers in nuclear medicine?
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Answer A radioisotope must be important in body processes and accumulate in the organism being studied.
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Advisory Good morning! Today we are going to hand out grades
Then at 10:50 we will take a tour of the career center. Advisory: 11:01– 11: min Hour 3: 11:57 – 1:21 Lunch A: 11:51–12:21 Class from 12:27-1:21 Lunch B: 12:21–12:51 Class from 11:57-12:21 And 12:54-1:21 Lunch C: 12:51–1:21 Class from 11:57-12:51 Hour 4: 1:27 – 2: min Hour 5: 2:19 – 3: min
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