Alpha decay - Revision history

Jmdonev: 1 revision imported

2026-08-04T20:43:46Z

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energy>Jmdonev at 20:31, 6 July 2026

2026-07-06T20:31:16Z

← Older revision		Revision as of 20:31, 6 July 2026
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	[[File:alphadecay.png\|360px\|thumb\|right\|Figure 1. A model of alpha decay, showing the ejection of an alpha particle from a nucleus.<ref>Wikimedia Commons. (July 22, 2015). ''Alpha Decay'' [Online]. Available: https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Alpha_Decay.svg/1280px-Alpha_Decay.svg.png</ref>]]		[[File:alphadecay.png\|360px\|thumb\|right\|Figure 1. A model of alpha decay, showing the ejection of an alpha particle from a nucleus.<ref>Wikimedia Commons. (July 22, 2015). ''Alpha Decay'' [Online]. Available: https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Alpha_Decay.svg/1280px-Alpha_Decay.svg.png</ref>]]
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	==Applications and Importance==		==Applications and Importance==
	[[File:InsideSmokeDetector.jpg\|360px\|thumb\|right\|Figure 3. The inner workings of a smoke detector.<ref>By MD111 (https://www.flickr.com/photos/md111/3266158320/) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons (Accessed May 8th, 2018.) from https://upload.wikimedia.org/wikipedia/commons/2/23/InsideSmokeDetector.jpg</ref>]]		[[File:InsideSmokeDetector.jpg\|360px\|thumb\|right\|Figure 3. The inner workings of a smoke detector.<ref>By MD111 (https://www.flickr.com/photos/md111/3266158320/) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons (Accessed May 8th, 2018.) from https://upload.wikimedia.org/wikipedia/commons/2/23/InsideSmokeDetector.jpg</ref>]]
	[[Radioactivity\|Radioactive]] elements that undergo alpha decay are used in smoke detectors (see Figure 3). [[Americium]] is one frequently used element as it is a major alpha particle source. Inside the smoke ~~detertor~~ alpha particles are released. This in turn [[ionization\|ionizes]] the air inside the detector. Smoke in the detector absorbs this alpha radiation, so if smoke is present the ionization is altered and the alarm is triggered.<ref>BBC Bitesized. (July 22, 2015). ''Uses of Radiation'' [Online]. Available: http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/living_future/4_nuclear_radiation2.shtml</ref>		[[Radioactivity\|Radioactive]] elements that undergo alpha decay are used in smoke detectors (see Figure 3). [[Americium]] is one frequently used element as it is a major alpha particle source. Inside the smoke detector alpha particles are released. This in turn [[ionization\|ionizes]] the air inside the detector. Smoke in the detector absorbs this alpha radiation, so if smoke is present the ionization is altered and the alarm is triggered.<ref>BBC Bitesized. (July 22, 2015). ''Uses of Radiation'' [Online]. Available: http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/living_future/4_nuclear_radiation2.shtml</ref>

	As well, alpha particles are used in a process known as Alpha Particle X-Ray Spectroscopy (APXS). This process is used to determine the elemental composition of rocks and soil. NASA used this method in its missions to Mars, including the Pathfinder missions, to determine what elements existed Martian rocks.<ref name=uses>ChemTeacher. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://chemteacher.chemeddl.org/services/chemteacher/index.php?option=com_content&view=article&id=65</ref>		As well, alpha particles are used in a process known as Alpha Particle X-Ray Spectroscopy (APXS). This process is used to determine the elemental composition of rocks and soil. NASA used this method in its missions to Mars, including the Pathfinder missions, to determine what elements existed Martian rocks.<ref name=uses>ChemTeacher. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://chemteacher.chemeddl.org/services/chemteacher/index.php?option=com_content&view=article&id=65</ref>

Jmdonev: 1 revision imported

2018-05-11T18:17:07Z

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Jmdonev at 22:36, 8 May 2018

2018-05-08T22:36:19Z

← Older revision		Revision as of 22:36, 8 May 2018
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	[[File:alphadecay.png\|360px\|thumb\|right\|Figure 1. A model of alpha decay, showing the ejection of an alpha particle from a nucleus.<ref>Wikimedia Commons. (July 22, 2015). ''Alpha Decay'' [Online]. Available: https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Alpha_Decay.svg/1280px-Alpha_Decay.svg.png</ref>]]		[[File:alphadecay.png\|360px\|thumb\|right\|Figure 1. A model of alpha decay, showing the ejection of an alpha particle from a nucleus.<ref>Wikimedia Commons. (July 22, 2015). ''Alpha Decay'' [Online]. Available: https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Alpha_Decay.svg/1280px-Alpha_Decay.svg.png</ref>]]

	<onlyinclude>'''Alpha decay''' is a [[nuclear decay]] process where an unstable [[nucleus]] [[transmutation\|~~transmutes~~]] ~~and ejects~~ a particle composed of two [[proton]]s and two [[neutron]]s.<ref>Jefferson Lab. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://education.jlab.org/glossary/alphadecay.html</ref> This ejected particle is known as an alpha particle and is simply a [[helium]] nucleus.</onlyinclude> Alpha particles have a relatively large mass and a positive charge, ~~resulting in~~ a ~~very short penetration range~~. ~~Because of this~~, alpha decay is rarely used in external [[medical isotope\|medical radiation]] therapy.<ref name="RE1">HyperPhysics. (July 22, 2015). ''Alpha Radioactivity'' [Online]. Available: http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radact.html#c2</ref>		<onlyinclude>'''Alpha decay''' is a [[nuclear decay]] process where an unstable [[nucleus]] [[transmutation\|changes to another element]] by shooting out a particle composed of two [[proton]]s and two [[neutron]]s.<ref>Jefferson Lab. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://education.jlab.org/glossary/alphadecay.html</ref> This ejected particle is known as an alpha particle and is simply a [[helium]] nucleus.</onlyinclude> Alpha particles have a relatively large mass and a positive charge. This large mass means alpha particles can't go very far through the air, or get very deep into a solid. Alpha particles only affect surfaces, so alpha decay is rarely used in external [[medical isotope\|medical radiation]] therapy.<ref name="RE1">HyperPhysics. (July 22, 2015). ''Alpha Radioactivity'' [Online]. Available: http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radact.html#c2</ref>

	Alpha decay was originally distinguished from other forms of radiation by Ernest Rutherford by observing the deflection of the radiation through a [[magnetic field]]. Alpha decay deflects in the way you would expect a positive particle to since alpha particles have a <m>+2e</m> charge.<ref name="RE2">StudyPhysics. (July 22, 2015). ''Alpha, Beta, and Gamma Decay'' [Online]. Available: http://www.studyphysics.ca/2007/30/08_atomic/43_decay.pdf</ref>		Alpha decay was originally distinguished from other forms of radiation by Ernest Rutherford by observing the deflection of the radiation through a [[magnetic field]]. Alpha decay deflects in the way you would expect a positive particle to since alpha particles have a <math>+2e</math> charge.<ref name="RE2">StudyPhysics. (July 22, 2015). ''Alpha, Beta, and Gamma Decay'' [Online]. Available: http://www.studyphysics.ca/2007/30/08_atomic/43_decay.pdf</ref>

	The general equation representing alpha decay is:		The general equation representing alpha decay is:

	<center><m>^A_ZX \rightarrow ^{A-4}_{Z-2}Y + ^4_2He</m></center>		<center><math>^A_ZX \rightarrow ^{A-4}_{Z-2}Y + ^4_2He</math></center>

	where:		where:
	* <m>^A_ZX</m> is the parent nucleus		* <math>^A_ZX</math> is the parent nucleus, the starting nucleus.
	* <m>^{A-4}_{Z-2}Y</m> is the daughter nucleus		* <math>A</math> Is the total number of [[nucleon]]s (the number of neutrons plus the number of protons).
	* <m>^4_2He</m> is the released alpha particle		* <math>Z</math> Is the total number of protons.
			* <math>^{A-4}_{Z-2}Y</math> is the daughter nucleus, the ending nucleus
			* <math>^4_2He</math> is the released alpha particle

	==Safety==		==Safety==
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	==Applications and Importance==		==Applications and Importance==
	[[Radioactivity\|Radioactive]] elements that undergo alpha decay are used in smoke detectors. [[Americium]] is one frequently used element as it is a major alpha particle source. Inside the smoke detertor alpha particles are released. This in turn [[ionization\|ionizes]] the air inside the detector. Smoke in the detector absorbs this alpha radiation, so if smoke is present the ionization is altered and the alarm is triggered.<ref>BBC Bitesized. (July 22, 2015). ''Uses of Radiation'' [Online]. Available: http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/living_future/4_nuclear_radiation2.shtml</ref>		[[File:InsideSmokeDetector.jpg\|360px\|thumb\|right\|Figure 3. The inner workings of a smoke detector.<ref>By MD111 (https://www.flickr.com/photos/md111/3266158320/) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons (Accessed May 8th, 2018.) from https://upload.wikimedia.org/wikipedia/commons/2/23/InsideSmokeDetector.jpg</ref>]]
			[[Radioactivity\|Radioactive]] elements that undergo alpha decay are used in smoke detectors (see Figure 3). [[Americium]] is one frequently used element as it is a major alpha particle source. Inside the smoke detertor alpha particles are released. This in turn [[ionization\|ionizes]] the air inside the detector. Smoke in the detector absorbs this alpha radiation, so if smoke is present the ionization is altered and the alarm is triggered.<ref>BBC Bitesized. (July 22, 2015). ''Uses of Radiation'' [Online]. Available: http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/living_future/4_nuclear_radiation2.shtml</ref>

	As well, alpha particles are used in a process known as Alpha Particle X-Ray Spectroscopy (APXS). This process is used to determine the elemental composition of rocks and soil. NASA used this method in its missions to Mars, including the Pathfinder missions, to determine what elements existed Martian rocks.<ref name=uses>ChemTeacher. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://chemteacher.chemeddl.org/services/chemteacher/index.php?option=com_content&view=article&id=65</ref>		As well, alpha particles are used in a process known as Alpha Particle X-Ray Spectroscopy (APXS). This process is used to determine the elemental composition of rocks and soil. NASA used this method in its missions to Mars, including the Pathfinder missions, to determine what elements existed Martian rocks.<ref name=uses>ChemTeacher. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://chemteacher.chemeddl.org/services/chemteacher/index.php?option=com_content&view=article&id=65</ref>

	Alpha particles do also have some use in the medical field. A new cancer treatment known as targeted alpha therapy or TAT uses alpha decay to kill cancer cells. [[lead\|Lead-212]] is ingested and travels to the site of the tumor, then giving off alpha [[radiation]] which kills all the cells in the area.<ref name=uses/>		Alpha particles do also have some use in the medical field. A new cancer treatment known as targeted alpha therapy or TAT uses alpha decay to kill cancer cells. [[lead\|Lead-212]] is ingested and travels to the site of the tumor, then giving off alpha [[radiation]] which kills all the cells in the area.<ref name=uses/>

	==PhET==		==PhET==
	The [http://phet.colorado.edu/ University of Colorado] has graciously allowed us to use the following PhET simulation. This simulation illustrates how radioactive nuclei decay through alpha decay, and shows the half-life of these atoms.		The [http://phet.colorado.edu/ University of Colorado] has graciously allowed us to use the following PhET simulation. This simulation illustrates how radioactive nuclei decay through alpha decay, and shows the half-life of these atoms.
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			== For further reading ==
			For further information please see the related pages below:
			*[[Half life]]
			*[[Beta decay]]
			*[[Gamma decay]]
			*[[Strong nuclear force]]
			*[[Special:Random\|or explore a random page!]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	~~[[Category:Uploaded]]~~

J.williams: 1 revision imported

2015-08-26T21:30:45Z

1 revision imported

← Older revision	Revision as of 21:30, 26 August 2015
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J.williams at 16:40, 12 August 2015

2015-08-12T16:40:19Z

New page

[[Category:Done 2015-07-24]]
[[File:alphadecay.png|360px|thumb|right|Figure 1. A model of alpha decay, showing the ejection of an alpha particle from a nucleus.<ref>Wikimedia Commons. (July 22, 2015). ''Alpha Decay'' [Online]. Available: https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Alpha_Decay.svg/1280px-Alpha_Decay.svg.png</ref>]]

<onlyinclude>'''Alpha decay''' is a [[nuclear decay]] process where an unstable [[nucleus]] [[transmutation|transmutes]] and ejects a particle composed of two [[proton]]s and two [[neutron]]s.<ref>Jefferson Lab. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://education.jlab.org/glossary/alphadecay.html</ref> This ejected particle is known as an alpha particle and is simply a [[helium]] nucleus.</onlyinclude> Alpha particles have a relatively large mass and a positive charge, resulting in a very short penetration range. Because of this, alpha decay is rarely used in external [[medical isotope|medical radiation]] therapy.<ref name="RE1">HyperPhysics. (July 22, 2015). ''Alpha Radioactivity'' [Online]. Available: http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radact.html#c2</ref>

Alpha decay was originally distinguished from other forms of radiation by Ernest Rutherford by observing the deflection of the radiation through a [[magnetic field]]. Alpha decay deflects in the way you would expect a positive particle to since alpha particles have a <m>+2e</m> charge.<ref name="RE2">StudyPhysics. (July 22, 2015). ''Alpha, Beta, and Gamma Decay'' [Online]. Available: http://www.studyphysics.ca/2007/30/08_atomic/43_decay.pdf</ref>

The general equation representing alpha decay is:

<center><m>^A_ZX \rightarrow ^{A-4}_{Z-2}Y + ^4_2He</m></center>

where:
* <m>^A_ZX</m> is the parent nucleus
* <m>^{A-4}_{Z-2}Y</m> is the daughter nucleus
* <m>^4_2He</m> is the released alpha particle

==Safety==
Although not very penetrating, the ingestion of a substance that undergoes alpha decay is harmful as the ejected alpha particles can damage internal tissues very easily despite its short range. This damage is a result of contact with membranes and living cells.<ref name="RE1"/> Figure 2 shows a diagram that illustrates the different levels of penetration for different types of radiation.

[[File:radiation_revised_2.png|400px|framed|center|Figure 2. Different penetration levels of different products of decay, with [[gamma decay|gamma]] being one of the most highly penetrating and alpha being one of the least penetrating.<ref>Chubu Electric Power. (May 26, 2015). ''Characteristics of radiation and radioactivity'' [Online]. Available: http://hamaoka.chuden.jp/english/radioactivity/aspect.html</ref><ref name=pic>''Created internally by a member of the Energy Educaation team''.</ref>]]

Overall, the health effects of alpha particles vary with how the exposure takes place. If the alpha emitter is inhaled, swallowed, or absorbed into the blood stream there can be lasting biological damage. This damage increases a persons risk of cancer. Alpha radiation is known to cause lung cancer in humans if the alpha emitter is inhaled. The inhalation of [[radon]], an alpha emitter, is one of the biggest sources of alpha decay related illness in humans.<ref name=epa>US EPA. (July 22, 2015). ''Alpha Particles'' [Online]. Available: http://www.epa.gov/radiation/understand/alpha.html#properties</ref>

==Applications and Importance==
[[Radioactivity|Radioactive]] elements that undergo alpha decay are used in smoke detectors. [[Americium]] is one frequently used element as it is a major alpha particle source. Inside the smoke detertor alpha particles are released. This in turn [[ionization|ionizes]] the air inside the detector. Smoke in the detector absorbs this alpha radiation, so if smoke is present the ionization is altered and the alarm is triggered.<ref>BBC Bitesized. (July 22, 2015). ''Uses of Radiation'' [Online]. Available: http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/living_future/4_nuclear_radiation2.shtml</ref>

As well, alpha particles are used in a process known as Alpha Particle X-Ray Spectroscopy (APXS). This process is used to determine the elemental composition of rocks and soil. NASA used this method in its missions to Mars, including the Pathfinder missions, to determine what elements existed Martian rocks.<ref name=uses>ChemTeacher. (July 22, 2015). ''Alpha Decay'' [Online]. Available: http://chemteacher.chemeddl.org/services/chemteacher/index.php?option=com_content&view=article&id=65</ref>

Alpha particles do also have some use in the medical field. A new cancer treatment known as targeted alpha therapy or TAT uses alpha decay to kill cancer cells. [[lead|Lead-212]] is ingested and travels to the site of the tumor, then giving off alpha [[radiation]] which kills all the cells in the area.<ref name=uses/>

==PhET==
The [http://phet.colorado.edu/ University of Colorado] has graciously allowed us to use the following PhET simulation. This simulation illustrates how radioactive nuclei decay through alpha decay, and shows the half-life of these atoms.
<center>
<html>
<div style="position: relative; width: 300px; height: 197px;"><a href="http://phet.colorado.edu/sims/nuclear-physics/alpha-decay_en.jnlp" style="text-decoration: none;"><img src="http://phet.colorado.edu/sims/nuclear-physics/alpha-decay-600.png" alt="Alpha Decay" style="border: none;" width="300" height="197"/><div style="position: absolute; width: 200px; height: 80px; left: 50px; top: 58px; background-color: #FFF; opacity: 0.6; filter: alpha(opacity = 60);"></div><table style="position: absolute; width: 200px; height: 80px; left: 50px; top: 58px;"><tr><td style="text-align: center; color: #000; font-size: 24px; font-family: Arial,sans-serif;">Click to Run</td></tr></table></a></div>
</html>
</center>

==References==
{{reflist}}
[[Category:Uploaded]]