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Topic: Atomic nuclei

In the News (Thu 21 Mar 19)

  13 - Kanarev - The Foundations of Physchemistry of Microworld
96 a) and the atomic nuclei of copper (Fig.
As there are chromium atoms, which, as we think, are formed from the atomic nuclei of iron, on the cathode surface (Table 47) 4fold more than the atoms of copper, the solution is sure to have superfluous protons and neutrons of the destroyed atomic nuclei of iron, and we can determined their approximate relative quantity.
Transmutation of the atomic nuclei of alkaline metals and the atomic nuclei of the cathode material during plasma electrolysis of water increases the content of gases in the gas-vapour mixture.
www.guns.connect.fi /innoplaza/energy/story/Kanarev/book/13.html   (2470 words)

  Atomic bonding
Atomic nuclei are pulled together by the electrostatic attraction between negatively-charged electron clouds and positively-charged nuclei.
Atomic nuclei are kept apart by Schrödinger pressure.
Atomic material is simply a suspension of nuclei (to a first approximation).
www.vendian.org /envelope/dir0/bond.html   (785 words)

  Glossary [A-Bomb to AWACS] | atomicarchive.com
The atomic bomb is an explosive device that depends upon the release of energy in a nuclear reaction known as fission, which is the splitting of atomic nuclei.
The atomic number of an element, which indicates its place in the periodic table of elements, is the number of protons (positively charged particles) in the nucleus of one of its atoms.
Atomic number is often symbolized with the letter Z and is shown as a numerical subscript to the left of its chemical symbol.
www.atomicarchive.com /Glossary/Glossary1.shtml   (1027 words)

 Atomic Nuclei   (Site not responding. Last check: )
Rutherford speculated existence of neutral particles in atomic nuclei.
Atomic weight average mass of all isotopes of an element.
Atomic mass of a nuclide is the mass of an isotope or nuclide.
www.science.uwaterloo.ca /~cchieh/cact/nuctek/atomnuclei.html   (256 words)

 Columbia Encyclopedia- nucleus - AOL Research & Learn
Atomic nuclei are composed of two types of particles, protons and neutrons, which are collectively known as nucleons.
The mass number of a given isotope is the nearest whole number to the atomic weight of that isotope and is approximately equal to the atomic weight (in the case of carbon-12, exactly equal).
In heavier nuclei the effect of electrostatic repulsion among the larger number of charges from the protons raises the energy of the protons, with the result that there are more neutrons than protons (for uranium-235, for example, there are 143 neutrons and only 92 protons).
reference.aol.com /columbia/_a/nucleus/20051206232209990029   (1751 words)

 How Heavy Can Atomic Nuclei Be?   (Site not responding. Last check: )
With the synthesis and detection of five new chemical elements—the elements with atomic numbers 107, 108, and 109 in the years 1981-1984, and those with atomic numbers 110 and 111 at the end of 1994—a GSI research group stands uncontested at the forefront of worldwide efforts to expand the table of the elements upwards.
The question concerning the upper limits of stability of atomic nuclei - practically speaking, the question of the maximum size and weight they may attain - is not only of fundamental importance for the physics of nuclear structure.
For the precise identification of the implanted nuclei, their decay characteristics are determined with the help of the silicon detectors: the entire decay chain is traced from the implanted parent nucleus through the daughter isotope down to the granddaughters and great-granddaughters.
www.gsi.de /portrait/Broschueren/Wunderland/03_e.html   (2511 words)

 Chapter I: Introduction (Nuclear Physics to 1940)
Specifically, such a conversion is observed in the phenomenon of nuclear fission of uranium, a process in which atomic nuclei split into fragments with the release of an enormous amount of energy.
Thus all the atoms of a given chemical element have the same atomic number, and conversely all atoms having the same atomic number are atoms of the same element regardless of possible differences in their nuclear structure.
nuclei; or four neutrons in each nucleus must convert themselves to protons by emitting electrons, thereby forming stable tin nuclei of mass number 119 and atomic number 50; or a combination of such ejections and conversions must occur to give some other pair of stable nuclei.
www.cddc.vt.edu /host/atomic/nuketech/smyth01.html   (8273 words)

 Phase Transitions in Atomic Nuclei
Taking a new approach to the analysis of existing experimental data, the researchers found the strongest evidence to date that atomic nuclei can be made to undergo a "phase transition" and change from a liquid to a vapor state.
To understand the nature of atomic nuclei, scientists have long treated the nuclei as tiny drops of liquid, for which the physical properties and behaviors have been well-characterized.
With their phase diagram, the Berkeley Lab researchers say that, given the size of the fragmented nuclei and the energy that was used to fragment them, they can predict the temperatures and pressures under which the nuclei will change from the liquid to the vapor phase.
www.lbl.gov /Science-Articles/Archive/NS-phase-transitions.html   (906 words)

 Atomic Nuclei   (Site not responding. Last check: )
Atomic nuclei are composite particles made up of protons and neutrons.
In order to better understand atomic nuclei, we first make an analogy with molecules.
We then investigate the binding energies of atomic nuclei.
www.physics.nmt.edu /~raymond/classes/ph13xbook/node214.html   (59 words)

 The Effects of Nuclear Weapons, 1977: General Principles of Nuclear Explosions
The resulting atomic species, which have identical atomic numbers but which differ in their masses, are called "isotopes" of the particular element.
In a nuclear explosion, on the other hand, the energy is produced as a result of the formation of different atomic nuclei by the redistribution of the protons and neutrons within the interacting nuclei.
It is for the same reason, too, that atomic weapons are preferably called "nuclear weapons." The forces between the protons and neutrons within atomic nuclei are tremendously greater than those between the atoms; consequently, nuclear energy is of a much higher order of magnitude than conventional (or chemical) energy when equal masses are considered.
www.cddc.vt.edu /host/atomic/nukeffct/enw77a.html   (10113 words)

 Chapter I. Introduction | Atomic Energy for Military Purposes (The Smyth Report) | Historical Documents | ...
Evidently the nuclei in the middle of the periodic table - nuclei of mass numbers 40 to 100 - are the most strongly bound.
First we assumed that mass and energy were equivalent; now we are assuming that atomic nuclei can be rearranged with a consequent reduction in their total mass, thereby releasing energy which can then be put to use.
This was particularly true for the elements of highest atomic number and weight where the large nuclear charge exerts strong repulsive forces on deuteron or proton projectiles but not on uncharged neutrons.
www.atomicarchive.com /Docs/SmythReport/smyth_i-b.shtml   (4029 words)

Collective motion of protons and neutrons in atomic nuclei is studied in the framework of the time-dependent relativistic mean-field theory.
Collective dynamics in atomic nuclei is studied in the framework of the information theory.
Atomic nuclei in the time dependent relativistic mean field model have shown interesting regular and chaotic dynamics in quantum systems.
www.phy.hr /~npaar/bologna2000/bologna2000.html   (759 words)

 Tom’s Infinite Science Archive: Atom and Atomic Theory
The observation that many atomic weights are close to whole numbers led the British chemist William Prout to suggest in 1816 that all elements might be composed of hydrogen atoms.
By the middle of the 19th century several chemists recognized that similarities in the chemical properties of various elements implied a regularity that might be illustrated by arranging the elements in a tabular or periodic form.
The least stable arrangement of nuclei is one in which an odd number of neutrons and an odd number of protons are present; all but four isotopes containing nuclei of this kind are radioactive.
www.angelfire.com /vt/VortexTom/Infinite.Atom.html   (4679 words)

 Nobel Prize in Physics 1961 - Presentation Speech
A theory for the atomic nuclei was proposed according to which they are composed of protons and neutrons which are together called the nucleons.
As the dimensions of the atomic nuclei are of the order of a ten-billionth of a centimeter, Hofstadter had in order to find their structure to bombard them with electrons of a very high energy.
You have in your pioneering investigations on the atomic nuclei and the single nucleons, revealed features of their structures which are fundamentally important for the understanding of these almost inconceivably small systems.
nobelprize.org /nobel_prizes/physics/laureates/1961/press.html   (1119 words)

 Atomic Nuclei   (Site not responding. Last check: )
The atomic number of an atom represents the number of orbiters in a particular element, which in turn represents the net positive "charge" (a misnomer) on the nucleus of the atom.
All atomic particles are micro reproductions of the structure of the Primordial Singularities.
Both neutrons and atomic nuclei are two concentric shells of electrons and protons with the proton shell being in the center.
www.newphysics2000.org /nuclei.htm   (2677 words)

 The Atomic Nuclei
Be) with the alpha particles (the nuclei of helium).
In the periodic table the number of protons is represented with the atomic number Z. For example the hydrogen nucleus includes one proton, the oxygen nucleus - eight, and the silver nucleus - forty-seven.
In the periodic table the mass of the nucleus is represented with the mass number A. So if a nucleus consists of 5 protons and 5 neutrons then the atomic number is equal to 5, and the mass number is equal to 10.
library.thinkquest.org /28383/nowe_teksty/htmla/2_23a.html   (583 words)

 [No title]
The force that holds electrons in their atomic orbits is the familiar electrostatic force, which was well understood long before the advent of atomic physics.
The stable nuclei in which Z and N are both even outnumber comfortably those in which either Z or N is odd, and there are only four stable nuclei in which both Z and N are odd.
Nuclei in which Z is magic tend to have larger numbers of stable isotopes than average.
www.colorado.edu /physics/TZD/NewChapters/EucCh16.doc   (6938 words)

 Physics at Trinity College Dublin - Schools - Atoms   (Site not responding. Last check: )
The neutrons are uncharged, so the number of protons in a nucleus is the atomic number of the element: 6 in the case of carbon.
Atoms which have the same number of protons in their nuclei but different numbers of neutrons are different isotopes of the element.
There are none in most hydrogen nuclei, but about fifteen hydrogen atoms in every thousand are atoms of deutrium or 'heavy hydrogen', with a proton and a neutron in the nucleus.
www.tcd.ie /Physics/Schools/what/atoms/nuclei.html   (1103 words)

 Texas A&M scientists study how atomic nuclei liquefy and vaporize by using the detector NIMROD At the Texas A&M ...
To study how nuclei undergo changes from solid to liquid to gas, Texas A&M University scientists smash atomic nuclei together in an on-site accelerator, the Cyclotron.
The two nuclei mix together, creating a very hot intermediate state where some nuclei are liquefied and others are vaporized.
NIMROD is cylindrical in shape, and consists mainly of concentric layers of numerous small detectors used to detect charged particles, and a large detector surrounding the small detectors, used to detect neutral particles.
www.eurekalert.org /pub_releases/2000-12/TAU-TAss-1012100.php   (639 words)

 Atomic nuclei formation   (Site not responding. Last check: )
By the time the Universe was one minute old, the formation of atomic nuclei by nuclear fusion became significant.
Neutrons and protons began to combine to produce nuclei of deuterium (one proton and one neutron), and then tritium (one proton and two neutrons).
The nuclei of other elements, such as beryllium and lithium, were also built up.
library.thinkquest.org /C006781F/atomic.htm   (140 words)

 Phase transition phenomena in atomic nuclei
The structure of these atomic nuclei can differ significantly from the typical structures of stable nuclei in the same mass range.
Presumably, the structure of these nuclei can be classified in several phases, with possible transitions between phases in function of the proton or neutron number or the temperature.
Consequently, the structure of atomic nuclei exhibits a wide spectrum of possible excitation modes.
www.kvi.nl /~fantom/abstractrombouts03.htm   (245 words)

 Atomic Nuclei   (Site not responding. Last check: )
An atomic nucleus is a bound system made up of one or more "nucleons".
Two nuclei can only be made to fuse if they approach each other with sufficient energy to overcome this repulsion.
It has atomic number 1 and mass 2, which means it is made up of 1 proton and 1 neutron (1 charged particle, 2 total; the units are the atomic charge and mass units).
www.ipp.mpg.de /~bds/phys/nuclei.html   (421 words)

 [No title]
Such polarization can  be shown to imply that the gravitational force between two objects is an electrostatic dipole force where the dipole lengths increase with their separation and similarly for the magnetic force between a pair of current carrying wires or magnetic elements.
That is, this action whether a push or a pull acts on the  electrostatic dipoles inside the nuclei in the same direction as it acts on the electrostatic dipoles in the free electrons which thus tend to move together.
Over typical values of current and voltage, and for what amounts to a standard distance(on the order of centimeters) between current carrying wires when their ponderomotive forces are measured by what is called a galvanometer or ammeter,  current is proportional to voltage; also the time between thermal collisions is constant for a range of temperatures.
mysite.verizon.net /r9ns/book03.htm   (5165 words)

 Gravity & Magnetism - A Common Cause? - Mountain Man's Usenet Archive
Thus the outer positive pole of the earth's atomic dipoles are attracted to the negative outer pole of the sun's atomic dipoles..
Now the largest distance between atomic nuclear dipoles on the earth implicitly determining the maximal size of the dipoles is about 10^6 meters whereas the distances for planets to the sun is 5.79(10^10) for mercury, (1.49)(10^11) for earth to 5.9(10^12) meters for pluto and for the sun to the galactic center 10^4 parsecs= (3)(10^20) meters.
The more atomic nuclei there are in the body and the greater its velocity components the greater the gravitational and magnetic fields of the body.
www.mountainman.com.au /news96_f.html   (3395 words)

 An Analysis of Same-Atomic-Weight Isotopes
For example, if the atomic number and atomic weight are related by a simple fraction, there is usually a large preference (downward residual) (added stability for that isotope), while if either is a prime number, or if the two have no simple relationship, there is usually a strong negative preference (upward residual).
In certain (even atomic weight) isotope weight families, there is an (odd atomic number) isotope very near the center of the parabola which has an atomic weight that is higher than the adjacent even atomic number isotopes, because they each have an extra 2-symmetry preference (both even atomic weight and even atomic number).
Along this reasoning, if both the number of protons and the atomic weight is even, the nucleus would be especially stable for having a double symmetry, so much so that an isotope of equal atomic weight and atomic number either one higher or lower is generally unstable with beta decay.
mb-soft.com /public2/nuclei6.html   (9634 words)

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