
	Where results make sense

Topic: Proton proton chain

	Proton-proton chains - Science Articles
		The proton-proton chain reaction (also known as the PP chain) is one of two fusion reactions by which stars convert hydrogen to helium, the other being the CNO cycle.
		The proton-proton chain is more important in stars the size of the Sun or less.
		H, releasing a positron as one proton changes into a neutron, and a neutrino.
	www.physicspost.com /science-article-188.html (430 words)

	Spartanburg SC \| GoUpstate.com \| Spartanburg Herald-Journal (Site not responding. Last check: 2007-11-06)
		Protons are spin-1/2 fermions and are composed of three quarks, making them baryons.
		Protons and neutrons are both nucleons, which may be bound by the nuclear force into atomic nuclei.
		Due to their stability and large mass (compared to electrons), protons are well suited to use in particle colliders such as the Large Hadron Collider at CERN and the Tevatron at Fermilab.
	www.goupstate.com /apps/pbcs.dll/section?category=NEWS&template=wiki&text=proton (779 words)

	Finance Choices - Personal Finance Wiki (Site not responding. Last check: 2007-11-06)
		Protons are spin-1/2 fermions and are composed of three quarks, making them baryons.
		Protons and neutrons are both nucleons, which may be bound by the nuclear force into atomic nuclei.
		Due to their stability and large mass (compared to electrons), protons are well suited to use in particle colliders such as the Large Hadron Collider at CERN and the Tevatron at Fermilab.
	www.financechoices.co.uk /personal-finance-wiki.php?title=Proton (787 words)

	Proton
		The nucleus of the most common isotope of the hydrogen atom, H, is a single proton.
		The number of protons in the nucleus determines the chemical properties of the atom and what chemical element it is.
		In chemistry and biochemistry, the term proton may refer to the hydrogen ion in aqueous solution (in other words, the hydronium ion).
	www.guajara.com /wiki/en/wikipedia/p/pr/proton.html (256 words)

	Science Fair Projects - Proton-proton chain reaction
		The proton-proton chain reaction is one of two fusion reactions by which stars convert hydrogen to helium, the other being the CNO cycle.
		After the development of quantum mechanics, it was discovered that the tunneling of the wave functions of the protons through the repulsive barrier allowed for fusion at a lower temperature than the classical prediction.
		The pp III chain is not a major source of energy in the Sun (as the Sun's core temperature is not high enough), but was very important in the solar neutrino problem because it generates the highest energy neutrinos (≤14.06 MeV).
	www.all-science-fair-projects.com /science_fair_projects_encyclopedia/Proton-proton_chain (801 words)

	Proton-proton chain reaction - Definition, explanation
		The proton-proton chain reaction is one of two fusion reactions by which stars convert hydrogen to helium, the other being the CNO cycle.
		After the development of quantum mechanics, it was discovered that the tunneling of the wave functions of the protons through the repulsive barrier allowed for fusion at a lower temperature than the classical prediction.
		The pp III chain is not a major source of energy in the Sun (as the Sun's core temperature is not high enough), but was very important in the solar neutrino problem because it generates the highest energy neutrinos (≤14.06 MeV).
	www.calsky.com /lexikon/en/txt/p/pr/proton_proton_chain_reaction.php (619 words)

	The Major World -The Sun as a nuclear reactor
		Four protons do not combine directly to form a helium nucleus, since the protons are constantly moving and are almost never in the same place at the same time.
		Instead, the protons come together in a series of steps to form a helium nucleus, and these steps are called the proton-proton chain.
		The two protons combine, with most of their mass forming a deuteron, the nucleus of a heavy form of hydrogen known as deuterium.
	library.thinkquest.org /C001124/gather/ssun.html?tqskip1=1&tqtime=0625 (1640 words)

	CNO cycle Summary
		While the proton-proton chain is more important in stars the mass of the sun or less, theoretical models show that the CNO cycle is the dominant source of energy in heavier stars.
		The net result of the cycle is to fuse four protons into an alpha particle plus two positrons and two neutrinos, releasing energy in the form of gamma rays.
		The carbon, oxygen, and nitrogen nuclei serve as catalysts and are regenerated.
	www.bookrags.com /CNO_cycle (957 words)

	Proton Summary
		Protons may be transmuted into neutrons by inverse beta decay (that is, by capturing an electron); since neutrons are heavier than protons, this process does not occur spontaneously but only when energy is supplied.
		These spectra depend on the shielding around the protons in the nuclei of that substance, which is provided by the surrounding electron clouds.
		Due to their stability and large mass (compared to electrons), protons are well suited to use in particle colliders such as the Large Hadron Collider at CERN.
	www.bookrags.com /Proton (1664 words)

	CiteULike: Structure and dynamics of a proton wire: a theoretical study of H+ translocation along the single-file water ... (Site not responding. Last check: 2007-11-06)
		CiteULike: Structure and dynamics of a proton wire: a theoretical study of H+ translocation along the single-file water chain in the gramicidin A channel.
		Structure and dynamics of a proton wire: a theoretical study of H+ translocation along the single-file water chain in the gramicidin A channel.
		Rather, proton transfer in the wire is a semicollective process that results from the subtle interplay of rapid hydrogen-bond length fluctuations along the water chain.
	www.citeulike.org /user/Pedrora/article/694719 (740 words)

	Proton - Glasgledius (Site not responding. Last check: 2007-11-06)
		The nucleus of the most common isotope of the hydrogen atom, H, is a single proton.
		The number of protons in the nucleus determines the chemical properties of the atom and what chemical element it is.
		In chemistry and biochemistry, the term proton may refer to the hydrogen ion in aqueous solution (in other words, the hydronium ion).
	www.glasglow.com /E2/pr/Proton.html (215 words)

	Proton-proton chain
		The proton-proton chain reaction (also known as the PP chain) is one of two fusion reactions by which stars convert hydrogen to helium, the other being the CNO cycle.
		The proton-proton chain is more important in stars the size of the Sun or less.
		H, releasing a positron as one proton changes into a neutron, and a neutrino.
	www.ebroadcast.com.au /lookup/encyclopedia/pr/Proton-proton_chain.html (259 words)

	DeftCOM Systems Limited, A New Century Entity (Site not responding. Last check: 2007-11-06)
		The dominant energy-producing reaction at the core is the proton-proton chain.
		The helium nuclei are slightly less massive than the protons that combined to produce them, and this residual mass is released as energy.
		This reaction causes four protons or hydrogen nuclei to fuse together to form one alpha particle or helium nucleus.
	webpages.charter.net /dosvader/Sun.html (1434 words)

	Proton - Search Results - MSN Encarta
		Proton, elementary particle that carries a positive electric charge and, along with the electron and the neutron, is one of the building blocks of...
		Four protons do not combine directly to form a helium nucleus, since the protons are constantly moving and are almost never in the same place at the...
		Sun: The Proton-Proton Chain, Hans Albrecht Bethe, scientist who discovered the chain
	ca.encarta.msn.com /Proton.html (122 words)

	Genesis : Search for Origins \| JPL \| NASA
		In the sun's core neither hydrogen molecules nor neutral hydrogen atoms with one proton in the nucleus and one orbital electron are present.
		Only a few super-high-speed protons have enough kinetic energy to tunnel through the electrostatic repulsion barrier and fuse together, initiating the chain of events that ultimately provides the energy from the sun's core.
		In this reaction one of the protons has been changed into a neutron, with the formation of a new nucleus containing one proton and one neutron.
	genesismission.jpl.nasa.gov /science/mod3_SunlightSolarHeat/FusionChemistry (1367 words)

	Genesis : Search for Origins \| JPL \| NASA
		In the sun's core neither hydrogen molecules nor neutral hydrogen atoms with one proton in the nucleus and one orbital electron are present.
		In the mid-1930s, after the discovery of the neutron in 1932 and the construction of machines that could accelerate particles, fusion reactions were demonstrated in earth-bound laboratories and the essential correctness of the theoretical predictions regarding fusion in the sun was established.
		The hydrogen nuclei (protons) at the sun's core are hydrogen atoms from which electrons have been ripped away (ionized nuclei).
	www.genesismission.org /science/mod3_SunlightSolarHeat/FusionChemistry (1367 words)

	Proton-proton fusion
		The fusing of two protons which is the first step of the proton-proton cycle created great problems for early theorists because they recognized that the interior temperature of the sun (some 14 million Kelvins) would not provide nearly enough energy to overcome the coulomb barrier of electric repulsion between two protons.
		With the development of quantum mechanics, it was realized that on this scale the protons must be considered to have wave properties and that there was the possibility of tunneling through the coulomb barrier.
		In the proton-proton fusion process, deuterium is produced by the weak interaction in a quark transformation which converts one of the protons to a neutron.
	hyperphysics.phy-astr.gsu.edu /hbase/astro/procyc.html (403 words)

	Proton-Proton chain (Site not responding. Last check: 2007-11-06)
		An important reaction in this process is that of "proton conversion." In this reaction, a proton is converted into a neutron.
		The resulting combination is not stable, and one of the protons will decay to become a neutron, and this forms a stable nucleus of deuterium.
		In this step, two protons are released that continue to participate in Step 1 or Step 2.
	aether.lbl.gov /www/tour/elements/stellar/pp.html (247 words)

	Astrophysics Glossary
		This used up the all the free neutrons and some protons, and caused the neutron line to drop off, and the proton line to dip (relatively few protons are used up).
		Hydrogen burning is the fusion of four hydrogen nuclei (protons) into a single helium nucleus (two protons and neutrons.) The process is a series of reactions.
		Since deuterium (a proton and a neutron) could not be formed, there were no large molecules.
	ie.lbl.gov /education/glossary/Glossarya.htm (1401 words)

	SUN
		In the first reaction of the p-p chain, a proton decays into a neutron in the immediate vicinity of another proton.
		The deuterium nucleus produced in the pp- or pep-reaction fuses with another proton to form helium-3 and a gamma ray.
		Only once for every 5000 completions of the p-p chain, beryllium-7 reacts with a proton to produce boron-8 which immediately decays into two helium-4 nuclei, a positron and an electronneutrino.
	www.columbia.edu /~ah297/unesa/sun/sun-chapter4.html (554 words)

	Hydrogen
		Two protons react to form deuteron, consisting of a proton and a neutron, after emitting a neutrino and a positron.
		Since the proton and the neutron in a deuteron have their spins aligned, the magnetic moment of the deuteron should be the sum of the individual moments, and indeed it is, very closely, at 0.8574 nuclear magnetons.
		The 21-cm radiation is caused by a flip of the electron and proton spins from antiparallel to parallel, or from total angular momentum F from 0 to 1.
	www.du.edu /~jcalvert/phys/hydrogen.htm (7686 words)

	PROTON-PROTON CHAIN
		In the Sun and other less massive stars, this chain is the primary source of heat and radiation.
		PP1 chain is dominant in temperatures of 10-14 million Kelvin.
		PP2 chain is dominant in temperatures of 14-23 million Kelvin.
	www.websters-online-dictionary.org /definition/english/Pr/Proton-Proton+Chain.html (517 words)

	THE ELECTRON TRANSPORT CHAIN
		Cytochrome a: position 2 has a 17-carbon side chain, position 4 is vinyl and position 8 has -CHO (instead of the usual CH Chlorins are hemes in which one or more of the pyrrole rings are reduced.
		Protons are picked up on the outside and released on the inside.
		The simplest scheme for ATP synthesis postulates removal of an oxygen from inorganic phosphate by two protons from the outside thus producing water on the outside and ATP on the inside.
	www.science.siu.edu /microbiology/micr425/425Notes/07-Respire.html (3207 words)

	The Proton-Proton Chain (Site not responding. Last check: 2007-11-06)
		The Proton-Proton or PP Chain, which is important in stars the mass of the Sun and less.
		The primary reactions in the main branch of the PP chain are illustrated in the following figure.
		Two mass-1 isotopes of hydrogen undergo a simultaneous fusion and beta decay to produce a positron, a neutrino, and a mass-2 isotope of hydrogen (deuterium).
	csep10.phys.utk.edu /astr162/lect/energy/ppchain.html (308 words)

	Main Sequence Stars
		The net effect of the process is that four hydrogen nuclei, protons, undergo a sequence of fusion reactions to produce a helium-4 nucleus.
		A rarer event is the ppIII chain whereby a Be-7 nucleus produced as above fuses with a proton to form B-8 and release a gamma photon.
		The first stage of the pp chain involves two protons fusing together whereas in the CNO cycle, a proton has to fuse with a carbon-12 nucleus.
	outreach.atnf.csiro.au /education/senior/astrophysics/stellarevolution_mainsequence.html (3202 words)

	ESA Science & Technology: Stellar Radiation & Stellar Types
		The simplest reaction to be found in stars is the conversion of hydrogen into helium - a process known as the proton-proton chain.
		In this process six hydrogen atoms are needed to create one helium nucleus of two protons and two neutrons.
		The overall process results in 4 protons (hydrogen nuclei) becoming a helium-4 nucleus, two positrons, two neutrinos and two gamma-rays.
	sci.esa.int /science-e/www/object/index.cfm?fobjectid=35774 (420 words)

	Chapter 16, Section 5 (Site not responding. Last check: 2007-11-06)
		In effect, one of the protons turns into a neutron, creating new particles in the process, and combines with the other proton to form a deuteron, the nucleus of a special form of hydrogen called deuterium.
		Nuclei such as normal hydrogen and deuterium, containing the same number of protons but different numbers of neutrons, represent different forms of the same element—they are known as isotopes of that element.
		The two leftover protons are available as fuel for new proton—proton reactions, so the net effect is that four protons are fused to form one helium-4 nucleus.
	astronomy.nju.edu.cn /astron/at3/AT31605.HTM (1857 words)

	Proton-proton chain reaction - RecipeFacts (Site not responding. Last check: 2007-11-06)
		The proton-proton chain dominates in stars the size of the Sun or less.
		The pp III chain is not a major source of energy in the Sun (only 0.11%), but was very important in the solar neutrino problem because it generates very high energy neutrinos (up to 14.06 MeV).
		Comparing the mass of the final helium-4 atom with the masses of the four protons reveals that 0.007 or 0.7% of the mass of the original protons has been lost.
	www.recipeland.com:8080 /facts/Proton-proton_chain_reaction (856 words)

	Module 26
		We find that the core of the Sun must be at about 15 million K. At 15 million K, hydrogen nuclei (protons) are moving fast enough to overcome their mutual + to + electrostatic repulsion, and stick together by nuclear forces which only act over very short distances (like glue or velcro).
		In a series of three nuclear reactions called the proton-proton chain, 4 protons eventually are bound together into a helium nucleus consisting of 2 protons and 2 neutrons.
		In the process 2 of the protons are converted into neutrons by ejecting positrons, positively charged anti-electrons.
	www.physics.utoledo.edu /~lsa/_a1010/mod26.htm (693 words)

	Neutrinos from the Sun
		, an atom with 17 protons and 20 neutrons.
		The proton-proton reaction is the slowest in the proton-proton chain, and hence it determines the overall rate at which energy is produced.
		PROTON PROTON CHAIN is thought to be the dominant source of energy generation in the sun.
	www.sns.ias.edu /~jnb/Papers/Popular/Scientificamerican69/scientificamerican69.html (5383 words)

Try your search on: Qwika (all wikis)