why is there a radioactive source in a smoke detector course hero

by Evelyn Hill 6 min read

Question: Why Is There A Radioactive Source In A Smoke Detector?Answer It Makes The Smoke Particles Radioactive. It Ionizes The Air. It Powers The Alarm When The Battery Wears Out. None Of The Above. This problem has been solved! it makes the smoke particles radioactive. it ionizes the air.

Full Answer

Why is there a radioactive source in smoke detectors?

Why is there a radioactive source in a smoke detector? Answer it makes the smoke particles radioactive. it ionizes the air. it powers the alarm when the battery wears out. none of the above.

What is the source of alpha particles in a smoke detector?

Ionization smoke detectors use americium as a source of alpha particles. Alpha particles from the americium source ionize air molecules. This makes some particles positively charged and some negatively charged.

How do ionization smoke detectors work?

Ionization smoke detectors use a small amount of radioactive material, americium-241, to detect smoke. Ionization smoke detectors use americium as a source of alpha particles. Alpha particles from the americium source ionize air molecules.

What is the difference between ionization and smog detectors?

Smoke detectors are common household items that keep you and your family safe by alerting you to smoke in your home. Ionization smoke detectors use a small amount of radioactive material, americium-241, to detect smoke. Ionization smoke detectors use americium as a source of alpha particles.

Why is there a radioactive source in a smoke detector?

Ionization-type smoke alarms have a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and activating the alarm.

Do smoke detectors use radioactive decay?

How they work. Ionization chamber smoke detectors rely on radiation to "ionize" the air inside the chamber. A radioactive source "decays," or sheds particles and photons from unstable atoms.

What type of radiation is smoke detectors?

Ionisation chamber smoke detectors The Am-241 radioactive source emits two types of radiation – alpha radiation and gamma radiation. The alpha radiation ionises the air within the metal chamber. A low electric voltage applied across the chamber causes a current to flow through the ionised air.

Why should the radiation source in a smoke alarm have a long half-life?

The source should have a long half-life so that the smoke detector does not have to be replaced too frequently, and so that the count rate remains almost constant each day. Radioactive isotopes can be used as medical and industrial tracers.

Where do radioactive substances come from?

Natural radioactive elements are present in very low concentrations in Earth's crust, and are brought to the surface through human activities such as oil and gas exploration or mining, and through natural processes like leakage of radon gas to the atmosphere or through dissolution in ground water.

How much radiation does a smoke detector emit?

around one microcurieBut things aren't so bad; smoke alarms only use a tiny amount, around one microcurie or less of radioactive material. Almost all smoke-detectors will use a radioactive substance called americium-241.

How does a smoke detector work?

The short answer. Smoke alarms detect fires by sensing small particles in the air using a couple of different kinds of technologies. Once they detect those particles above a certain threshold, they signal the alarm to sound so that you and your family can get to safety and call 911. Smoke alarms save lives.

What type of radioactive decay is used in smoke detectors apex?

α emissionThe isotope of americium used in smoke detectors is americium-241, which decays by α emission to neptunium-237 with a half-life of 432.2 years.

How to use a smoke detector?

What You Can Do 1 Use a smoke detector in your home. It can save your life. 2 Never tamper with an ionization smoke detector. Never attempt to tamper with or remove the americium. 3 Replace the batteries. Replace the batteries in every smoke detector in your home twice a year. Most detectors are certified for a useful life of ten years. Check the expiration date on your smoke detector when you replace the batteries. 4 Throw away outdated ionization smoke detectors. Your community may have a separate recycling program for them.

What is the ionization of smoke detectors?

Ionization smoke detectors use americium as a source of alpha particles. Alpha particles from the americium source ionize air molecules. This makes some particles positively charged and some negatively charged. Two charged plates inside of the ionization smoke detector create a flow of positively and negatively charged ions.

How does a smoke alarm work?

The smoke alarm triggers when smoke breaks the constant flow of ions. Alpha particles are very heavy and cannot travel very far. They can be shielded by a layer as thin as a layer of dead skin cells. Ionization smoke detectors have a small americium source encased in a layer of foil and ceramic, which stops the alpha particles from traveling ...

What is the americium used for in a smoke detector?

Smoke detectors are common household items that keep you and your family safe by alerting you to smoke in your home. Ionization smoke detectors use a small amount of radioactive material, americium-241, to detect smoke. On this page: About Americium in Ionization Smoke Detectors. What you can do.

Can americium be thrown away?

They may be thrown away with household garbage, or your community may have a separate recycling program. This diagram shows how an americium source ionizes air particles and makes an ionization smoke detector work.

Is a smoke detector a radiation detector?

Because of this shielding, the smoke detector poses no radiation health risk when they are properly handled. There is no health threat from ionization smoke detectors as long as the detector is not damaged and used as directed. Do not tamper with your smoke detectors, as it could damage the shielding around the radioactive source inside of them.