A+Smoke+Detectors

=__Isotope and Radioactivity__ = = = = Name of radioactive isotope/electromagnetic radiation/scientist: Smoke Detectors invented by Duane D. Pearsall and Stanley Bennett Peterson in 1965 = = = = = =Explanation of interesting facts: (how used/works.experiments/discoveries) =  =3 Advantages of using the radioactive isotope/radiation/benefits of discovery =  1. The smoke detector lets you know when there's a fire and it can help you to stop if before it spreads. It can also point you to where the fire is in the building.
 * 1) The alpha particles are constantly released by the Americium knock off electrons on the atoms in the air, it ionizes the oxygen and nitrogen atoms in the chamber.
 * 2) Positively-charged oxygen and nitrogen atoms are attracted to the negative plate, and the electrons are attracted to the positive plate, generating a small, continuous electric current.
 * 3) Any smoke that enters the chamber absorbs the alpha particles, which reduces the ionization and interrupts this current, setting off the alarm.
 * 4) 2.6-5.0% obs/m (0.8-1.5% obs/ft)
 * 5) drop in current between the plates triggers the alarm.

2. You can connect with the local rescue unit so that they can respond right away as soon as your alarm system sounds. It lets the fire departments know that there is a fire in your house.

3. Having a smoke detector is a great advantage because, 1) It lets you know when there's a fire, and 2) Where the fire is. If you can not get out of your house on time you are in a great amount of danger. Fires spread very quickly so if you can't get to a fire extinguisher in time get out of your house and make sure everyone is out. =Is the radioactive isotope/radiation/discovery still used today? Explain =  Yes the Smoke Detectors are still used today. People have them in their houses,schools,work places,etc. We use them because if there is a fire and we don't know there's a fire the smoke detector will go off and let you know to get out of your house.If you are cooking something and there is a lot of smoke the smoke detector will go off to. The smoke detector is a very helpful thing because there has been deaths from fires because sometimes there can be a fire in the middle of the night in your house and you would not know about it and if you don't have a smoke detector you would not be able to get out of your house on time before the fire gets to where you are in the house. Everyone needs a smoke detector in there house in case of a fire.

=References =  -http://en.wikipedia.org/wiki/Smoke_detector -http://chemistry.about.com/cs/howthingswork/a/aa071401a.htm -http://ezinearticles.com/?The-Advantages-of-Installing-Smoke-Detectors-at-Home&id=1931446

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