25.4 Radiation in Your Life > 1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Chapter 25 Nuclear Chemistry 25.1 Nuclear

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<ul><li> Slide 1 </li> <li> 25.4 Radiation in Your Life &gt; 1 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Chapter 25 Nuclear Chemistry 25.1 Nuclear Radiation 25.2 Nuclear Transformations 25.3 Fission and Fusion 25.4 Radiation in Your Life </li> <li> Slide 2 </li> <li> 25.4 Radiation in Your Life &gt; 2 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. How does a smoke detector work? CHEMISTRY &amp; YOU A typical household smoke detector contains a small amount of americium, Am, in the form of AmO 2. Americium-241 is a radioisotope. 241 95 </li> <li> Slide 3 </li> <li> 25.4 Radiation in Your Life &gt; 3 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation What are three devices used to detect radiation? </li> <li> Slide 4 </li> <li> 25.4 Radiation in Your Life &gt; 4 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Radiation emitted by radioisotopes has enough energy to knock electrons off some atoms of a bombarded substance, producing ions. The radiation emitted by radioisotopes is called ionizing radiation. </li> <li> Slide 5 </li> <li> 25.4 Radiation in Your Life &gt; 5 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation It is not possible for humans to see, hear, smell, or feel ionizing radiation. People must rely on detection devices to alert them to the presence of radiation and to monitor its level. </li> <li> Slide 6 </li> <li> 25.4 Radiation in Your Life &gt; 6 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation It is not possible for humans to see, hear, smell, or feel ionizing radiation. People must rely on detection devices to alert them to the presence of radiation and to monitor its level. These devices work because of the effects of the radiation when it strikes atoms or molecules in the detector. </li> <li> Slide 7 </li> <li> 25.4 Radiation in Your Life &gt; 7 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Radiation can expose a photographic plate. When the plate is developed, its darkened areas show where the plate has been exposed to radiation. X-rays allow doctors to see inside the body without having to cut into the body. Color was added to highlight parts of the image. </li> <li> Slide 8 </li> <li> 25.4 Radiation in Your Life &gt; 8 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Radiation emitted in a smoke detector ionizes the nitrogen and oxygen in the air, and a current flows. When smoke particles attach to the ions, the ions lose their charge. What happens next? CHEMISTRY &amp; YOU </li> <li> Slide 9 </li> <li> 25.4 Radiation in Your Life &gt; 9 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Radiation emitted in a smoke detector ionizes the nitrogen and oxygen in the air, and a current flows. When smoke particles attach to the ions, the ions lose their charge. What happens next? CHEMISTRY &amp; YOU Once the ions in the air inside the smoke detector lose their charge, the current decreases. An electronic circuit detects the drop in current, which causes an alarm to sound. </li> <li> Slide 10 </li> <li> 25.4 Radiation in Your Life &gt; 10 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Geiger counters, scintillation counters, and film badges are commonly used to detect radiation. </li> <li> Slide 11 </li> <li> 25.4 Radiation in Your Life &gt; 11 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Geiger Counter A Geiger counter uses a gas-filled metal tube to detect radiation. When ionizing radiation penetrates a thin window at the end of the tube, the gas inside the tube becomes ionized. Each time a Geiger tube is exposed to radiation, current flows. The bursts of current drive electronic counters or cause audible clicks from a built-in speaker. </li> <li> Slide 12 </li> <li> 25.4 Radiation in Your Life &gt; 12 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Geiger Counter Geiger counters can detect alpha, beta, and gamma radiation. Astronomers use Geiger counters to detect cosmic rays from outer space. Geologists use Geiger counters to search for radioactive minerals. This person is using a Geiger counter to check for radiation in contaminated dirt at a spill site. </li> <li> Slide 13 </li> <li> 25.4 Radiation in Your Life &gt; 13 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Scintillation Counter A scintillation counter uses a phosphor- coated surface to detect radiation. When ionizing radiation strikes the surface, the phosphor produces bright flashes of light, or scintillations. The number of flashes and energies are detected electronically. </li> <li> Slide 14 </li> <li> 25.4 Radiation in Your Life &gt; 14 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Scintillation Counter Scintillation counters are more sensitive than Geiger counters. They can detect some radiation that would not be detected by a Geiger counter. Scintillation counters are used to track the path of radioisotopes through the body. They are also used to monitor the possible transport of radioactive materials across national borders and through airports. </li> <li> Slide 15 </li> <li> 25.4 Radiation in Your Life &gt; 15 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Film Badge This is a diagram of a typical film badge. The badge contains layers of photographic film covered with black light-proof paper. To reach the film, radiation must pass through a filter, which absorbs some radiation, or a transparent area through which radiation can pass easily. </li> <li> Slide 16 </li> <li> 25.4 Radiation in Your Life &gt; 16 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Detecting Radiation Film Badge People who work with or near ionizing radiation must wear a film badge to monitor their exposure while they are at work. At specific intervals, the film is removed and developed. The strength and type of radiation exposure are determined by comparing the darkness of the film in all the exposed areas. </li> <li> Slide 17 </li> <li> 25.4 Radiation in Your Life &gt; 17 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Which of the following detectors would you use to locate uranium ores in a soil sample? A.Geiger counter B.scintillation counter C.film badge </li> <li> Slide 18 </li> <li> 25.4 Radiation in Your Life &gt; 18 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Which of the following detectors would you use to locate uranium ores in a soil sample? A.Geiger counter B.scintillation counter C.film badge </li> <li> Slide 19 </li> <li> 25.4 Radiation in Your Life &gt; 19 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation What are some practical uses of radioisotopes? </li> <li> Slide 20 </li> <li> 25.4 Radiation in Your Life &gt; 20 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation What are some practical uses of radioisotopes? Although radiation can be harmful, it can be used safely and has many important applications. </li> <li> Slide 21 </li> <li> 25.4 Radiation in Your Life &gt; 21 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Radioisotopes are used to analyze matter, study plant growth, diagnose medical problems, and treat diseases. </li> <li> Slide 22 </li> <li> 25.4 Radiation in Your Life &gt; 22 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Scientists use radiation to detect trace amounts of elements in samples. This process is called neutron activation analysis. Analyzing Matter </li> <li> Slide 23 </li> <li> 25.4 Radiation in Your Life &gt; 23 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Analyzing Matter A sample is bombarded with neutrons from a radioactive source. Some atoms in the sample become radioactive. The half-life and type of radiation emitted can be detected and analyzed by a computer. Because this data is unique for each isotope, scientists can determine what radioisotopes were produced and infer what elements were in the original sample. </li> <li> Slide 24 </li> <li> 25.4 Radiation in Your Life &gt; 24 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Analyzing Matter Museums use this process to detect art forgeries. Crime laboratories use it to analyze gunpowder residue. </li> <li> Slide 25 </li> <li> 25.4 Radiation in Your Life &gt; 25 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Radioisotopes called tracers are used in agriculture to test the effects of herbicides, pesticides, and fertilizers on plants. A tracer is introduced into the substance being tested. Next, plants are treated with the tagged substance. Devices that detect radioactivity are used to locate the substance in the plants. Using Tracers </li> <li> Slide 26 </li> <li> 25.4 Radiation in Your Life &gt; 26 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation The tracer may also be monitored in animals that consume the plants, as well as in water and soil. Using Tracers </li> <li> Slide 27 </li> <li> 25.4 Radiation in Your Life &gt; 27 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Radioisotopes can be used to detect disorders of the thyroid gland, which is located in the throat. To diagnose thyroid disease, the patient is given a drink containing a small amount of the radioisotope iodine-131. After about two hours, the amount of iodide uptake is measured by scanning the patients throat with a radiation detector. Diagnosing Medical Problems </li> <li> Slide 28 </li> <li> 25.4 Radiation in Your Life &gt; 28 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation The radioisotope technetium-99m is used to detect brain tumors and liver disorders. Phosphorus-32 is used to detect skin cancer. Diagnosing Medical Problems </li> <li> Slide 29 </li> <li> 25.4 Radiation in Your Life &gt; 29 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Radiation is one method used in the treatment of some cancers. Treating Diseases Cancer is a disease in which abnormal cells in the body are produced at a rate far beyond the rate for normal cells. The mass of cancer cells that result from this runaway growth is called a tumor. </li> <li> Slide 30 </li> <li> 25.4 Radiation in Your Life &gt; 30 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Fast-growing cancer cells are more susceptible to damage by high-energy radiation such as gamma rays than are healthy cells. Treating Diseases Radiation can be used to kill the cancer cells in a tumor. </li> <li> Slide 31 </li> <li> 25.4 Radiation in Your Life &gt; 31 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Some normal cells are also killed, however, and cancer cells at the center of the tumor may be resistant to the radiation. Treating Diseases The benefits of the treatment and the risks to the patient must be carefully evaluated before radiation treatment begins. </li> <li> Slide 32 </li> <li> 25.4 Radiation in Your Life &gt; 32 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Some normal cells are also killed, however, and cancer cells at the center of the tumor may be resistant to the radiation. Treating Diseases The benefits of the treatment and the risks to the patient must be carefully evaluated before radiation treatment begins. Cobalt-60 and cesium-137 are typical radiation sources for cancer therapy. </li> <li> Slide 33 </li> <li> 25.4 Radiation in Your Life &gt; 33 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Salts of radioisotopes can also be sealed in gold tubes and directly inserted in tumors. Treating Diseases This method of treatment is called seeding. The salts emit beta and gamma rays that kill the surrounding cancer cells. Because the radioisotope is in a sealed container, it is prevented from traveling to other parts of the body. </li> <li> Slide 34 </li> <li> 25.4 Radiation in Your Life &gt; 34 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Using Radiation Prescribed drugs containing radioisotopes of gold, iodine, or phosphorus are sometimes used in radiation therapy. Treating Diseases A dose of iodine-131 larger than that used to detect thyroid diseases can be given to a patient to treat the disease. The iodine that collects in the gland emits beta particles and gamma rays, which provide therapy. </li> <li> Slide 35 </li> <li> 25.4 Radiation in Your Life &gt; 35 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Describe the benefits and risks of radiation therapy for cancer. </li> <li> Slide 36 </li> <li> 25.4 Radiation in Your Life &gt; 36 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Describe the benefits and risks of radiation therapy for cancer. Radiation therapy can kill cancer cells at a higher rate than healthy cells, so it can be used to destroy fast-growing tumors. However, it also damages healthy cells, and cells in the center of the tumor may not be reached by the radiation. </li> <li> Slide 37 </li> <li> 25.4 Radiation in Your Life &gt; 37 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Key Concepts Geiger counters, scintillation counters, and film badges are commonly used to detect radiation. Radioisotopes are used to analyze the composition of matter, study plant growth, diagnose medical problems, and treat diseases. </li> <li> Slide 38 </li> <li> 25.4 Radiation in Your Life &gt; 38 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Glossary Terms ionizing radiation: radiation with enough energy to knock electrons off some atoms of a bombarded substance to produce ions </li> <li> Slide 39 </li> <li> 25.4 Radiation in Your Life &gt; 39 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. Electrons and the Structure of Atoms The ability to detect particles emitted when nuclei decay helps scientists study processes that take place in living organisms. This ability also allows scientists to determine the age of fossils and other objects. BIG IDEA </li> <li> Slide 40 </li> <li> 25.4 Radiation in Your Life &gt; 40 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved. END OF 25.4 </li> </ul>