Americium smoke detector

Discharge water and emission from facilities that make americium smoke detectors or gauges or produce plutonium for nuclear weapons may contain americium. These operations are strictly regulated, but you can check local health advisories before consuming fish or other seafood from these waters. Nuclear reactors are not expected to discharge measurable amounts of americium. 

Smoke detectors contain a small amount of americium-241. Its de-... 

Smoke detectors contain small amounts of americium-241. Am-241 decays by emitting a-particles and has a decay constant of 1.51 X 10-3 y 1. If a smoke detector gives off ten disintegrations per second, how many grams of Am-241 are present in the detector ... 

The principle behind the home smoke detector is described on page 516. Americium-241 is present in such detectors. It has a decay constant of 1.51 X 10-3 y 1. You are urged to check the battery in the detector at least once a year. You are, however, never encouraged to check how much Am-241 remains undecayed. Explain why. 

Radioisotopes have important commercial applications. For example, americium-241 is used in smoke detectors. Its role is to ionize any smoke particles, which then allow a current to flow and set off the alarm. Exposure to radiation is also used to sterilize food and inhibit the sprouting of potatoes. Radioisotopes that give off a lot of energy as heat are also used to provide power in remote locations, where refueling of generators is not possible. Unmanned spacecraft, such as Voyager 2, are powered by radiation from plutonium. 

Ionization smoke detectors that contain americium are safe when installed. However, you should not allow your children to play with these detectors and they should be promptly returned to the manufacturer for disposal if they are damaged or no longer being used. 

Smoke detectors containing americium that are inoperable, damaged, or no longer needed should be returned to the supplier for disposal. 

UIC. 1997. Most smoke detectors contain an artificially produced radioisotope americium-241. Americium-241 is made in nuclear reactors, and is a decay product of plutonium-241. Uranium Information Center. Nuclear Issues Briefing Paper 35. http //www.uic.com.au/nip35.htm. January 27, 2000. 

Common radioactive material in use today includes the alpha emitters Americium-241 and Plutonim-238 the beta emitters Phosporus-32 and Strontium-90 and the gamma emitters Cesium-137, Cobalt-60, and Iridium-192 [44], These materials are commonly used in smoke detectors, oil exploration, industrial gauges, food and mail irradiation, cancer therapy, industrial radiography, and in research laboratories. 

All the isotopes and compounds of americium are deadly sources of radiation and cause radiation poisoning and death. Precautions must be taken when working with it. The small amount of americium-241 found in smoke detectors in household smoke alarms is harmless unless the isotope is removed and swallowed. 

Ionization smoke detectors contain a small radioactive source (Americium 241) which ionizes air in a small chamber. The ions flow to a charged plate giving a measurable current. Products of combustion in the chamber are not easily ionized and absorb the radiation and reduce the current. The low current trips the alarm circuit. The size and composition of the particles are crucial to successful detection so that some types of smoke or vapor are detected at very low (invisible) levels. 

American chemist Glenn T. Seaborg Artificially made and radioactive the alpha particles emitted by its isotope americium-24 1 enable the air to conduct electricity, making it useful in smoke detectors. 

The plutonium-241 that results from uranium-238 bombardment is itself radioactive with a half-life of 14.4 years, decaying by j3 emission to yield americium-241. (If the name sounds familiar, it s because americium is used commercially in making smoke detectors.) Americium-241 is also radioactive, decaying by a emission with a half-life of 432 years. 

Americium-241, a radioisotope used in smoke detectors, decays by a series of 12 reactions involving sequential loss of a, a, (3, a, a, (3, a, a, a, (3, a, and f3 particles. Identify each intermediate nuclide and the final stable product nucleus. 

Americium is a critical ingredient in smoke detectors. Some of the tiny particles released by an americium compound create a small electric charge inside smoke detectors. Smoke or soot can block the charge, which sets off the alarm. One gram of americium is enough for 5,000 smoke detectors. 

Radioactive substances also have life-saving uses. A radioactive form of cobalt is extensively used in radiation therapy for cancer patients. The treatment was first developed by Harold Johns (1915—) in Canada, where he pioneered cobalt therapy units at the University of Saskatchewan. One of the artificially made elements, Americium (atomic number 95, i.e., with 95 protons in its atomic nucleus), is another life-saving radioactive element. As it decays, it emits alpha particles, which strip electrons from surrounding gas molecules ionized air conducts electricity much better than air containing smoke particles, and the reduction in conductivity produced by smoke is what triggers the alarm in smoke detectors. 

We know that nuclear weapons are capable of mass destruction, yet radiation therapy, shown in Figure 4.18, is a proven cancer fighter. Smoke detectors, required by law in all homes, rely on the radioactive decay of americium-241. The human body itself is radioactive, due to the presence of radioactive isotopes including carbon-14, phosphorus-32, and potassium-40. Most people view radioactivity and nuclear reactions with a mixture of fascination, awe, and fear. Since radioactivity is all around us, it is important to understand what it is, how it arises, and how we can deal with it safely. 

Smoke detectors contain very small amounts of a radioactive isotope. When smoke enters the detector it is ionized by the radiation and this causes an electrical current to flow between two detection plates and the alarm goes off. The element often used is americium, an artificially made element. 

One type of commercial smoke detector contains a minute amount of radioactive americium-241 (241Am), which decays by a-particle production. The a particles ionize molecules in the air, allowing it to conduct an electric current. When smoke particles enter, the conductivity of the air changes and the alarm buzzes. 

Americium-241 is widely used in smoke detectors. The radiation released by this element ionizes particles that are then detected by a charged-particle collector. The half-life of 24IAm is 432.2 years, and it decays by emitting alpha particles. How many alpha particles are emitted each second by a 5.00-g sample of 241Am ... 

We also encounter radioactive elements every day in devices that normally perch quietly and inconspicuously on the ceiling of kitchens and halls smoke detectors. Smoke detectors Radioactive Yes. The working element of a smoke detector is a radioactive source, a sample of americium... 

Some brands of smoke detectors contain a very small amount of the radioactive element americium. 

A smoke detector contains a very small trace of americium-241 which decays by alpha release. What will be formed ... 

One of the simplest and cheapest safety devices found in homes and other buildings is a battery-operated smoke detector. And americium is an important part of it. A small piece of americium oxide made with the americium-241 isotope is sealed inside the smoke detector. The americium-241 gives off alpha particles. The alpha particles strike air molecules, causing them to break apart. The pieces formed in this process—ions—are electrically charged. 

Common smoke detectors include an americium oxide made with the americium 24l isotope. lAAAGE COPYRIGHT 2009, DANNY E. HOOKS. USED UNDER LICENSE FROM SHUTTERSTOCK.COM. 

Americium is an extremely toxic element. If swallowed, it is deposited in the bones. There, the radiation it gives off kills or damages cells, causing cancer. People are normally in no danger from smoke detectors containing americium-241. (Indeed, countless lives are saved each year because of smoke detectors.) The amount of this isotope in a smoke detector is very small. One gram of americium oxide made with americium-241 will make 5,000 smoke detectors. 

Smoke detectors depend on nuclear reactions to sound an alarm when a fire starts. Many smoke detectors contain a small amount of americium-241, which decays to form neptunium-237 and alpha particles. 

Explain why nuclei that emit alpha particles, such as americium-241, are safe to use in smoke detectors. 

This smoke detector needs to be replaced after about 10 years because the amount of americium steadily decreases. 

Actinide series Actinides are radioactive elements. Only three actinides exist in nature. The rest are synthetic elements called transuranium elements. A transuranium element is an element whose atomic number is greater than 92, the atomic number of uranium. Transuranium elements are created in particle accelerators or nuclear reactors. Most transuranium elements decay quickly. One notable exception is plutonium-239. A sample of this isotope can remain radioactive for thousands of years. Plutonium is used as a fuel in nuclear power plants. The home smoke detector in Figure 7-27b uses americium. 

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