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Topic: Alpha decay

Related Topics

Alpha emission

Beta decay

Radioactive decay

Neutron emission

Electron capture

Beta emission

Positron emission

Decay mode

Proton emission

Internal conversion

Radioactivity

Spontaneous fission

Beta ray

Beta particle

Gamma radiation

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	Alpha decay - Wikipedia, the free encyclopedia
		Alpha decay is a form of radioactive decay in which an atomic nucleus ejects an alpha particle through the electromagnetic force and transforms into a nucleus with mass number 4 less and atomic number 2 less.
		Alpha decay can essentially be thought of as nuclear fission where the parent nucleus splits into two daughter nuclei.
		Alpha decay is fundamentally a quantum tunneling process.
	en.wikipedia.org /wiki/Alpha_decay (306 words)

	Alpha particle - Wikipedia, the free encyclopedia
		Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper.
		In contrast to beta decay, alpha decay is mediated by the strong nuclear force.
		When an alpha particle is emitted, the atomic mass of an element goes down by roughly 4 amu, due to the loss of 4 nucleons.
	en.wikipedia.org /wiki/Alpha_particle (885 words)

	Alpha Decay
		Alpha radiation reduces the ratio of protons to neutrons in the parent nucleus, bringing it to a more stable configuration.
		In alpha decay, the atomic number changes, so the original (or parent) atoms and the decay-product (or daughter) atoms are different elements and therefore have different chemical properties.
		In the alpha decay of a nucleus, the change in binding energy appears as the kinetic energy of the alpha particle and the daughter nucleus.
	www.lbl.gov /nsd/education/ABC/wallchart/chapters/03/1.html (268 words)

	Alpha Decay (Site not responding. Last check: 2007-11-07)
		Alpha particles are helium nuclei released from an unstable nucleus.
		Alpha particles are emitted from the nucleus atom at 10 percent the speed of light.
		During alpha decay, the atomic mass of the element undergoing the change decreases by four and the atomic number by two.
	wey238ab.ch.iup.edu /Carl/alphadec.htm (170 words)

	Atoms - the inside story. Decay chains. (Site not responding. Last check: 2007-11-07)
		The decay chain was short and straightforward because phospherous is a light element and phospherous-35 is quite near the line of stability.
		Alpha decay always appears in decay chains of nuclides with an atomic number greater than 83.
		Notice that the effect of the alpha decay is to take the chain towards the line of stability, whose gradient is steeper than the gradient of an alpha emission.
	www.schoolscience.co.uk /content/5/physics/particles/partich2pg5.html (514 words)

	Radioactivity
		Radioactive decay rates are normally stated in terms of their half-lives, and the half-life of a given nuclear species is related to its radiation risk.
		The alpha particle is the nucleus of the helium atom and is the nucleus of highest stability.
		The energy of emitted alpha particles was a mystery to early investigators because it was evident that they did not have enough energy, according to classical physics, to escape the nucleus.
	hyperphysics.phy-astr.gsu.edu /hbase/nuclear/radact.html#c1 (564 words)

	Theory: Radioactive Decay
		It emerges from a weak decay process in which one of the neutrons inside an atom decays to produce a proton, the beta electron and an anti-electron-type neutrino.
		It is produced as a step in a radioactive decay chain when a massive nucleus produced by fission relaxes from the excited state in which it first formed towards its lowest energy or ground-state configuration.
		Alpha decay is also a type of fission, common because the alpha particle is a particularly low energy arrangement of two protons and two neutrons.
	www2.slac.stanford.edu /vvc/theory/nuclearstability.html (694 words)

	Glossary Item - Alpha Decay (Site not responding. Last check: 2007-11-07)
		Alpha decay is one process that unstable atoms can use to become more stable.
		During alpha decay, an atom's nucleus sheds two protons and two neutrons in a packet that scientists call an alpha particle.
		For example, after undergoing alpha decay, an atom of uranium (with 92 protons) becomes an atom of thorium (with 90 protons).
	education.jlab.org /glossary/alphadecay.html (72 words)

	Radioactivity
		Alpha particles are, in general, the least penetrating of the particles produced in a radioactive decay due to their relatively large size and their charge (+2e).
		Alpha particles are usually stopped or absorbed by a few centimeters of air or a sheet of paper.
		-decay is the decay of carbon to nitrogen:
	theory.uwinnipeg.ca /mod_tech/node179.html (476 words)

	Radiation Notes: Alpha and Beta Decay
		Alpha decay is a change from the ground state of an original nucleus to an excited or ground state of a daughter nucleus with the expulsion of an alpha particle.
		Beta decay presents a significantly different situation: there are three final objects, the daughter nucleus, the electron or positron, and the neutrino or antineutrino (see the next session for a further discussion of neutrinos).
		Because beta decay, which changes a neutron into a proton, leaves the atomic mass number A (which is equal to N+Z) unchanged, and alpha decay reduces A by 4, there are four distinct heavy-atom chains, known as the 4n, 4n+1, 4n+2, and 4n+3 chains.
	oak.cats.ohiou.edu /~piccard/radnotes/alphabeta.html#decays (4535 words)

	What are alpha rays? How are they...
		An alpha particle is made up of two protons and two neutrons, all held together by the same strong nuclear force that binds the nucleus of any atom.
		In fact, an alpha particle really is a nucleus - it's the same as the nucleus of a common atom of helium - but it doesn't have any electrons around it, and it's traveling very fast.
		The alpha particle is the radiation given off during the process of "alpha decay".
	education.jlab.org /qa/radbegin_04.html (720 words)

	Learn more about Alpha particle in the online encyclopedia. (Site not responding. Last check: 2007-11-07)
		Alpha particles or alpha rays are a form of particle radiation which are highly ionizing and have low penetration.
		They consist of two protons and two neutrons bound together into a particle that is identical to a helium nucleus, and can be written as He Alpha particles are emitted by radioactive nuclei such as uranium or radium in a process known as alpha decay.
		If alpha radiation does enter the body, however, they are the most dangerous form of ionizing radiation.
	www.onlineencyclopedia.org /a/al/alpha_particle.html (324 words)

	Alpha Decay (Site not responding. Last check: 2007-11-07)
		By emitting an alpha particle the atom is able to increase the stability by reducing the ratio of protons to neutrons.
		M represents the masses of the parent nucleus, daughter nucleus and alpha particle respectively and c is the speed of light.
		The probability of the alpha particle tunneling through the barrier is given by the square of the wave function of the particle.
	www.upei.ca /~physics/p221/pro00/alpha (1340 words)

	Radioactive Decay (Site not responding. Last check: 2007-11-07)
		A nucleus which decays by emitting an alpha particle loses two neutrons and two protons, in order to change its atomic number by -2 and mass number by -4.
		Alpha particles have two units of charge and tend to stop more easily than beta particles (which are electrons).
		If the nucleus falls apart into two pieces (as in alpha decay or in the more dramatic nuclear fission), the pieces are more tightly bound than the original nucleus, and energy is given up in that way.
	van.hep.uiuc.edu /van/qa/section/New_and_Exciting_Physics/Inside_the_Atom/20020816032607.htm (658 words)

	CERN Courier - Second postcard from the isl - IOP Publishing - article
		Its probable alpha decay leads to a daughter nucleus, the isotope 288/114 previously synthesized in the calcium-48/plutonium-244 reaction via the four-neutron evaporation channel.
		Thus, after the decay of the 292/116 nucleus, the whole decay chain of the daughter 288/114 nucleus should be observed (figure 1a).
		The alpha-particle energies and the half-lives of the nuclei in the three decay chains, the first alpha decays and those detected after the accelerator was switched off are all consistent between each other within the limits of the detector energy resolution (60 keV) and the statistical fluctuations in the decay time of the events.
	www.cerncourier.com /main/article/41/8/17 (1550 words)

	[No title]
		Alpha Decay An alpha particle is a He4 nucleus, that is, it consists of 2 protons and 2 neutrons.
		The alpha decay calculation was one of the first successes of the Schroedinger equation, and was the first demonstration of quantum mechanical tunneling.
		Gamma decay in the nucleus is similar to photon decay in atoms.
	www.csupomona.edu /~pbsiegel/www/bio431/Chapter3.doc (3626 words)

	[No title]
		Beta Decay: In this process, the parent nucleus spontaneously emits a “beta” particle, which is identical to the electron.
		Alpha particle: A group of 4 nucleons: 2 protons and 2 neutrons, emitted by a nucleus.
		Radioactive decay: The natural process by which one element decays into another element (or isotope) by the emission of alpha, beta or gamma rays.
	www.radon-test.com /courses/TechReview.doc (1648 words)

	alpha (Site not responding. Last check: 2007-11-07)
		Alpha decay is a radioactive process in which a particle with two neutrons and two protons is ejected from the nucleus of a radioactive atom.
		Alpha decay only occurs in very heavy elements such as uranium, thorium and radium.
		Thus, when uranium-238 (which has a Z of 92) decays by alpha emission, thorium-234 is created (which has a Z of 90).
	www.physics.isu.edu /radinf/alpha.htm (196 words)

	Nuclear Decay and Radioactive Series
		Nuclear decay occurs whenever a nucleus is in an energy state which is not the lowest possible for its "nucleon number" (A; a nucleon is a proton or a neutron).
		Alpha decay is most common for elements with Z > 82, since it provides the greatest energy loss per nucleon.
		Beta decay is the "transformation" of a neutron into a proton, with the emission of an electron for charge conservation, and an antineutrino (see section E below) for energy and momentum conservation.
	www.rwc.uc.edu /koehler/biophys/7c.html (696 words)

	ChemTeam: Writing Alpha and Beta Equations
		1) The nuclide that decays is the one on the left-hand side of the equation.
		As beta decay was studied over the years following 1899, it was found that the same exact beta decay produced an electron with variable energies.
		Later on, it was discovered that it was an antineutrino that was produced in beta decay.
	dbhs.wvusd.k12.ca.us /webdocs/Radioactivity/Writing-Alpha-Beta.html (634 words)

	[No title]
		Uranium-235 decays via a sequence of seven alpha decays and four beta decays to produce a stable nuclide.
		Fluorine-18 radioactively decays by the emission of a positron.
		The radioactive nuclide, iodine-131, is used medicinally as a radiotracer for the diagnosis and treatment of illnesses associated with the thyroid gland.
	www.chem.purdue.edu /gchelp/116exams/nuclear.html (2797 words)

	Howstuffworks "How Nuclear Radiation Works"
		An alpha particle is made up of two protons and two neutrons bound together, which is the equivalent of a helium-4 nucleus.
		In beta decay, a neutron in the nucleus spontaneously turns into a proton, an electron, and a third particle called an antineutrino.
		In many cases, a nucleus that has undergone alpha decay, beta decay or spontaneous fission will be highly energetic and therefore unstable.
	www.howstuffworks.com /nuclear2.htm (682 words)

	Positrons, Alpha Particles, and Gamma Rays (Site not responding. Last check: 2007-11-07)
		The applet will show you many other decays that produce either electrons or positrons; it's easy to tell which, by the "direction" in which the decay moves.
		Some heavy isotopes decay by spitting out alpha particles.
		After alpha or beta decay, a nucleus is often left in an excited state--that is, with some extra energy.
	www.colorado.edu /physics/2000/isotopes/radioactive_decay2.html (228 words)

	EPA - Decay Chains (EPA's Radiation Protection Program: Understanding Radiation) (Site not responding. Last check: 2007-11-07)
		As radioactive decay progresses, the concentration of the original radionuclides decreases, while the concentration of their decay products increases and then decreases as they undergo transformation.
		The importance of understanding decay chains is illustrated by the ingrowth of radon-222 during decay of uranium-238.
		Radon decay emits alpha particles, the radiation that presents the greatest hazard to lung tissue.
	www.epa.gov /radiation/understand/chain.htm (781 words)

	nuclear decay processes
		Alpha decay occurs when helium nuclei come flying off of the nucleus of a larger isotope, forming an isotope with a smaller mass.
		These helium nuclei are called alpha particles, and are the same things that Rutherford busily shot at a sheet of gold foil during his experiment where he discovered the nucleus.
		Gamma decay is when very high energy light called a gamma ray is emitted from a nucleus to bring it to a lower energy state.
	misterguch.brinkster.net /nucleardecay.html (346 words)

	Theory of Alpha Decay (Site not responding. Last check: 2007-11-07)
		These decays either involve a closed shell nucleus, or are to an excited state in the daughter nucleus.
		The ratio of the actual half-life to that predicted by the empirical line is known as the hindrance factor.
		Decays involving a change in angular momentum can be strongly hindered by the centrifugal barrier.
	www.phys.jyu.fi /research/gamma/publications/ptgthesis/node26.html (723 words)

	Alpha decay (from radioactivity) -- Encyclopædia Britannica
		In alpha decay, an energetic helium ion (alpha particle) is ejected, leaving a daughter nucleus of atomic number two less than the parent and of atomic mass number four less than the parent.
		Because alpha particles have two positive charges and a mass of four units, their emission from nuclei produces daughter nuclei having a positive nuclear charge or atomic number two units less than their parents and a mass of four...
		In the most common form of gamma decay, known as gamma emission, gamma rays (photons, or packets of electromagnetic energy, of extremely short wavelength) are radiated.
	www.britannica.com /eb/article-48273 (782 words)

	Decay
		Write the alpha decay equations for these five nuclides.
		Beta decay is somewhat more complex than alpha decay is. A simplified view of what beta decay actually is:
		Positron decay is like a mirror image of beta decay.
	www.tenafly.k12.nj.us /~shilfstein/worksheets.htm (847 words)

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