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Topic: Alpha rays


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  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)

  
  Radioactivity - Printer-friendly - MSN Encarta
In an electric field the path of the beta particles is greatly deflected toward the positive electric pole, that of the alpha particles to a lesser extent toward the negative pole, and gamma rays are not deflected at all.
Loss of an alpha particle by a nucleus results in the formation of a new nucleus, lighter than the original by four mass units (the masses of the neutron and of the proton are about one unit each).
The emission of gamma rays is a compensation by the atomic nucleus for the unstable state that follows alpha and beta processes in the nucleus.
encarta.msn.com /text_761569327___2/Radioactivity.html   (1491 words)

  
 radioactivity. The Columbia Encyclopedia, Sixth Edition. 2001-05
Alpha rays have the least penetrating power, move at a slower velocity than the other types, and are deflected slightly by a magnetic field in a direction that indicates a positive charge.
Beta rays are more penetrating than alpha rays, move at a very high speed, and are deflected considerably by a magnetic field in a direction that indicates a negative charge; analysis shows that beta rays are high-speed electrons (see beta particle; electron).
Gamma rays result from the transition of nuclei from excited states (higher energy) to their ground state (lowest energy), and their production is analogous to the emission of ordinary light caused by transitions of electrons within the atom (see atom; spectrum).
www.bartleby.com /65/ra/radioact.html   (1102 words)

  
 Radioactivity - MSN Encarta
Radioactivity, spontaneous disintegration of atomic nuclei by the emission of subatomic particles called alpha particles and beta particles, or of electromagnetic rays called X rays and gamma rays.
He also observed that the rays that produce the darkening are capable of discharging an electroscope, indicating that the rays possess an electric charge.
In 1898 the French chemists Marie Curie and Pierre Curie deduced that radioactivity is a phenomenon associated with atoms, independent of their physical or chemical state.
encarta.msn.com /encnet/refpages/RefArticle.aspx?refid=761569327   (1839 words)

  
 Alpha particle Summary
Alpha rays were moderately deflected in a direction opposite to that of the beta rays.
The identification of alpha particles as doubly-charged helium atoms, that is, as helium nuclei, was confirmed.
Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper.
www.bookrags.com /Alpha_particle   (2926 words)

  
 Radiation Basics - Alpha Particles   (Site not responding. Last check: )
Alpha particles are composite particles consisting of two protons and two neutrons tightly bound together (Figure 1).
Alpha particles are highly ionizing because of their double positive charge, large mass (compared to a beta particle)and because they are relatively slow.
Alpha particles (or alpha-rays) were the first nuclear radiation to be specifically identified and hence their name, alpha.
www.arpansa.gov.au /basics/alpha.htm   (511 words)

  
 x-rays, gamma rays, alpha rays, beta rays and other krap   (Site not responding. Last check: )
Gamma ray is a term for high-energy electromagnetic radiation produced by nuclear transitions, while X-ray is a term for high-energy electromagnetic radiation produced by energy transitions due to accelerating electrons.
Cosmic rays are high energy charged particles, originating in outer space, that travel at nearly the speed of light and strike the Earth from all directions.
Most cosmic rays are the nuclei of atoms, ranging from the lightest to the heaviest elements in the periodic table.
members.tripod.com /other_krap/x-rays.html   (433 words)

  
 Mars Exploration Rover Mission: The Mission
Alpha particles are emitted during radioactive decay and X-rays are a type of electromagnetic radiation, like light and microwaves.
The alphas are emitted and bounce back from a science target into a detector in the APXS, along with some X-rays that are excited from the target in the process.
The energy distribution of the alphas and X-rays measured by the detectors is analyzed to determine elemental composition.
marsrovers.jpl.nasa.gov /mission/spacecraft_instru_apxs.html   (209 words)

  
 ASI-website-faq
Alpha particles are randomly generated positively charged energetic nuclear particles originating from several sources, namely: extraterrestrial cosmic rays which come from outer space and constantly bombard the earth, and from the decay of natural occurring radioisotopes like Radon, Thorium, and Uranium.
Alpha particles are Helium nuclei, which are composed of two protons and two nuetrons and have a charge state of plus two.
Alpha radiation (or alpha rays) was distinguished and named by Rutherford in 1909, who found by measuring the charge and mass of alpha particles that they are the nuclei of ordinary helium atoms.
www.alphacounting.com /ASI-website-faq.htm   (1835 words)

  
 Radioactivity
Alpha rays are charged positively, beta rays negatively, and gamma rays are neutral.
Alpha rays are composed of a stream of helium nuclei, called alpha particles, and beta rays are composed of a stream of electrons, called beta particles.
Alpha particles, which are composed of two protons and two neutrons, result from the actual breakup of the atomic nucleus.
library.thinkquest.org /C004587/tutorials/modern/lesson21.htm   (896 words)

  
 alpha particle - HighBeam Encyclopedia   (Site not responding. Last check: )
alpha particle one of the three types of radiation resulting from natural radioactivity.
Alpha radiation (or alpha rays) was distinguished and named by E. Rutherford in 1909, who found by measuring the charge and mass of alpha particles that they are the nuclei of ordinary helium atoms.
Alpha particles consist of two protons and two neutrons (see nucleus).
www.encyclopedia.com /doc/1E1-alphapar.html   (265 words)

  
 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.
On the other hand, external alpha irradiation is not harmful because alpha particles are completely absorbed by a very thin (micrometers) dead layer of skin as well as by a few centimeters of air.
en.wikipedia.org /wiki/Alpha_decay   (402 words)

  
 The Alpha, Beta, and Gamma Radiation
At the end of the 19th century Thomson and Rutheford studied the phenomenon of the ionisation of gases illuminated with the rays discovered by Becquerel.
During the experiment Rutheford discovered that there were two kinds of such radiation: The first one called the alpha rays was easily absorbed even by paper; the second one called the beta rays could penetrate through even thick metal brasses like for example 0.25 centimetres of aluminium.
The alpha rays (having low penetrating power) consist of positively charged particles - in a magnetic field, and in an electric field alpha rays are deflected in the same direction as other positively charged particles.
library.thinkquest.org /28383/nowe_teksty/htmla/1_26a.html   (317 words)

  
 Primer on Radiation   (Site not responding. Last check: )
Alpha rays, or particles, are ionized nuclei of helium atoms.
Alpha rays and neutrons have a very high LET and can only penetrate a few hundredths of a metre.
Alpha rays and neutrons are likely to produce the greatest damage, but in a restricted area because they can barely penetrate the human skin, while gamma rays produce less damage but over a greater area because they penetrate deeper.
www.lehigh.edu /~kaf3/books/reporting/radioact.html   (1969 words)

  
 Alpha, beta, and gamma detectors
Alpha particles are heavy (as radiations go), consisting of 2 neutrons and 2 protons, and have a charge of +2, and typical alpha particle energies are in the range from 3 to 10 MeV(million electron volts).
Alpha particles travel very short distances in materials (often less than 100 micrometers in solid low-atomic-number materials) so the window must be quite thin, usually about 1/3 the thickness of a standard sheet of paper or less.
Even though the gamma rays from a specific decay transition are of a discrete energy, there is a statistical spread of pulses coming from the detector and associated electronics so that the gap between the discriminators must be large enough to include most of such pulses.
www.hps.org /publicinformation/ate/q534.html   (3265 words)

  
 radioactivity - HighBeam Encyclopedia   (Site not responding. Last check: )
Beta rays are more penetrating than alpha rays, move at a very high speed, and are deflected considerably by a magnetic field in a direction that indicates a negative charge; analysis shows that beta rays are high-speed electrons (see beta particle ; electron).
In beta decay a neutron within the nucleus changes to a proton, in the process emitting an electron and an antineutrino (the antiparticle of the neutrino, a neutral particle with a small mass).
Gamma rays result from the transition of nuclei from excited states (higher energy) to their ground state (lowest energy), and their production is analogous to the emission of ordinary light caused by transitions of electrons within the atom (see atom ; spectrum).
www.encyclopedia.com /doc/1E1-radioact.html   (1290 words)

  
 Geiger Counter Nuclear Radiation Monitor Detector Alpha Beta Gamma X-Ray
Alpha - the least penetrating form of radiation, can be stopped with a piece of paper or a few inches of air.
Alpha rays are the nucleus of a helium atom, and are produced by certain radiactive materials such as thorium and uranium.
Beta rays are more penetrating than alpha rays, and can be stopped by a few millimeters of aluminum or other metals.
www.blackcatsystems.com /GM/geiger_counter.html   (1108 words)

  
 Basics about radiation   (Site not responding. Last check: )
Alpha rays are produced following spontaneous decay of certain radioactive atoms, such as radium, plutonium, uranium, and radon.
A particle ray consisting of a fast electron whose mass is nearly 1/2000 of the mass of a proton or neutron.
As with alpha rays, the major concern for health effects is after their ingestion (ie, internal exposure).
www.rerf.or.jp /eigo/radefx/basickno/whatis.htm   (501 words)

  
 Gamma ray Summary
Gamma rays, such as those emitted from the unstable nuclei of cobalt-60 and cesium-137, are used in industry to assess the metallurgical integrity of, for example, pipes, girders, and turbine blades.
Gamma rays are a form of ionizing radiation; they are more penetrating than either alpha or beta radiation (neither of which is electromagnetic radiation), but less ionizing.
Np; this alpha decay is accompanied by gamma emission.
www.bookrags.com /Gamma_ray   (4640 words)

  
 Radiation Health Effects
Alpha rays are produced after spontaneous decay of radioactive atoms including radium, radon, uranium, and plutonium.
Alpha rays pass less than one millimeter in water, and because a single piece of paper can stop an alpha ray, health effects only appear when alpha-emitting particles are ingested.
X rays are similar to gamma rays, but they consist of an array of different wavelengths, whereas gamma rays have a fixed value specific to the radioactive material.
www-rcf.usc.edu /~meshkati/tefall99/part1.html   (963 words)

  
 Alpha particle - Wikipedia, the free encyclopedia
Alpha particles are emitted by radioactive nuclei such as uranium or radium in a process known as alpha decay.
This sometimes leaves the nucleus in an excited state, with the emission of a gamma ray removing the excess energy.
The physicist Ernest Rutherford famously used alpha particles to infer that J.
en.wikipedia.org /wiki/Alpha_rays   (874 words)

  
 Build Your Own Geiger Counter
Alpha rays are the nuclei of helium atoms, two protons and two neutrons bound together.
Alpha particles have weak penetrating ability, a couple of inches of air or a few sheets of paper can effectively block them.
Beta rays were found to be electrons, identical to the electrons found in atoms.
www.imagesco.com /articles/geiger/01.html   (367 words)

  
 [No title]
Alpha rays (which were the bullets used by Ernest Rutherford in his famous scattering experiment) are simply helium nuclei--each alpha ray (or particle) has two protons and two neutrons bound together.
Gamma rays are high-energy rays of light (remember that high energy means high frequency and high frequency means small wavelength).
Both gamma rays and beta rays can harm the stable nuclei within our bodies, but one of their more harmful abilities is to disrupt molecular bonds.
csma31.csm.jmu.edu /physics/mattson/lec16.doc   (398 words)

  
 [No title]
Marsden found that some alpha rays were scattered directly backwards, even from a thin film of gold.
Alpha particles carry a charge of +2 and strongly interact with matter.
Alpha particles are unable to penetrate even the thin layer of dead cells of human skin and consequently are not an external radiation hazard.
www.lycos.com /info/alpha-particle.html   (507 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.
The majority of cosmic rays (perhaps 85 percent) are protons traveling near the speed of light, while perhaps 12 percent are alpha particles traveling very quickly.
Primary cosmic rays are a danger to astronauts in outer space.
science.howstuffworks.com /nuclear2.htm   (758 words)

  
 Introduction to Atomic Reactions
It is fortunate that alpha radiation is relatively harmless when coming from external sources, outside of the body, because alpha radiation has the greatest capacity to ionize matter and cause damage to the body.
So Alpha radiation is the most deadly when ingested into the body because when the alpha emitting particles are in the actual tissues of the body, there is no dead skin (the epidermal layers of the skin) to stop the alpha rays before it reaches sensitive tissue.
Alpha particles are made of a particle that is identical to the nuclei of a helium 4 atom, having two protons and two neutrons, except that the alpha particle is moving fast, 1/10 the speed of light.
www.creation-science-prophecy.com /intro-atomic.htm   (2465 words)

  
 ChemTeam: Discovery of Alpha Scattering
She said that this showed that the alpha particles were not scattered, that is, able to be bent from their path.
The slight shift of the vacuum-lines in the figure, relative to the air-lines, was due to an accidental displacement of the plate in transferring the metal sheets in the middle of the experiment.
This scattering of the rays probably also occurs with aluminium, but it would not be as evident in the experiments where the layers of foil are placed over the active wire between the source and the slit.
dbhs.wvusd.k12.ca.us /webdocs/Radioactivity/Disc-of-Alpha-Scatter.html   (1086 words)

  
 Gifts of Speech - Irene Joliot-Curie
Fifteen years later, by bombarding with alpha rays certain of the lighter atoms, nitrogen and aluminium for example, Lord Rutherford demonstrated the ejection of protons, or positively charged hydrogen nuclei; this hydrogen came from the bombarded atoms themselves: it was the result of a transmutation.
In the course of recent years various artificial transmutations of different types have been discovered; some are produced by alpha rays, others by protons or deuterons, hydrogen nuclei of weight 1 or 2, others by neutrons, neutral particles of weight 1 about which Professor Chadwick has just spoken.
But the positive electrons produced by aluminium under the action of a source of alpha rays continue to be emitted for some time after removal of the source.
gos.sbc.edu /c/curie1935.html   (977 words)

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