What allows the passage of electrons, what does not allow the passage of electrons?
26943
It appears that the question period has expired.  If you have received an answer that meets your needs, please choose one of those as a 'best answer.'  If you haven't received a good answer for your question, you may want to consider the following,\n\n1) Re-post your question.  Newer questions get more activity on Yahoo! Answers than old ones.\n2) If you do re-post your question, consider why it wasn't answered the first time.  Could it be more specific?  Could it be worded better? Were there grammatical or spelling errors? Was it in the best category?\n\nIf it doesn't seem likely that re-posting your question will help you, then here's a listing of my favorite 'answer sites'.  Maybe one of them will help you.\n\nAnswers.com http://www.answers.com/\nBartleby http://www.bartleby.com/\nYahoo Reference http://education.yahoo.com/reference/\nHowStuffWorks http://www.howstuffworks.com/\nWikipedia http://en.wikipedia.org/wiki/Main_Page\n\nSince I really haven't answered your question, it is not necessary to give me any points.  Regards.
1171601
The conduction band is not really related to the energy levels of electrons in an atom. Instead, it is about how electrons behave in a crystal lattice.\n\nIf you think about it, when you try to get an electron to move through a solid, it is going to keep coming across nuclei that will stop it in its tracks or bounce it back. So how on earth does anything conduct?\n\nThe answer is that electrons behave like waves. So the crystal lattice behaves like a 3D diffraction grating. You will have seen 1D diffraction gratings  splitting light into a spectrum. What this tells you is that photon of a given energy can go easily in one direction but not at all in another (the dark bands). The same applies - but more complicated - to the electrons in a crystal (metals are crystalline in structure).\n\nYou can think of it this way - in some directions the electron can wiggle around all the nuclei because the spacing is a multiple of its wavelength, in others it cannot.\n\nBecause electrons are no free to move as they please in a metal then the usual rule that their energy will vary with the square of their momentum does not apply. The band structure of a material shows how energy and momentum are related. It varies in different directions in the material.\n\nImportantly, the band structure has a gap in it. This gap is the area where there is no momentum an electron can have to have a given energy (you can see why this exists above). The band below this gap is called the valence band. The band above is called the conduction band.\n\nBecause of the Pauli exclusion principle. no two electrons can have the same state (i.e. the same momentum/energy/spin relation). So the bands fill up from the bottom.\n\nTo conduct, it must be possible to add some momentum to an electron to make it move. You can see that if the valence band is full, then you have to give a lot of energy before you can change the momentum because there is a gap before you find a vacant state. \n\nMaterials with a full valence band and empty conduction band are insulators.\n\nMaterials with some electrons in their conduction band are conductors.
638239
A conductor will allow electricity to pass through it, an insulator will not
795070
as we all know, higher temperature, the electrons will get more energy.\nwhen electrons get more energy, they will become more active.\nwhen more active they will jump out from the place they were previously. what i mean is they will jump more faster and more regular than before.\nok now, common sense, the more they jump, they more more holes will be create.\n(as we all know, electrons occupy the holes.)\nthis is the answer.\n\nsimpe and clear\n\nmentioning about group VA of the periodic table (eg. phosphorus (P), arsenic (As), or antimony (Sb)), which incorporate into the crystal lattice in place of a Si atom, and their extra electrons are only weakly bound to the atom...dun really explain the situation.
542290
Charge is a fundamental property. This means that we simply accept charge as an attribute of the particles. Much like we accept a person's name.\n\nIn other words, we don't know what causes charge in the sense which you inquire to know, but it doesn't prevent us from working with the particles.\n\nCharge aside, electrons and protons are very different particles. Electrons orbit atoms and weight next to nothing, while protons are locked in the nucleus of the atom and are considerably more massive.
715376
It means that electrons have both particle-like and wave-like behaviour (for example they demonstrate interference).\n\nwavelength = planck's constant/(mass x velocity)
895042
All 's' can hold 2 electrons.\n\nAll 'p' can hold 8 electrons.\n\nAll 'd' can hold 18 electrons.\n\nAll 'f' can hold 32 electons.
889370
carbon has no free electrons available\nso it cannot conduct electricitys\nin case of germanium and si they have d orbits in the outer shell and they have greater mobility
1086480
Question:  Exactly how fast do electrons travel?\n------------------------------------------------\nAnswer:  Electrons can have a wide range of speeds.  A slow case: we know that\nelectrons move when there is a current flow in a wire, but the speed at\nwhich the electrons themselves move in the wire -- the so-called electron\ndrift velocity -- surprises most people.  For example, for a copper wire of\nradius 1 mm carrying a steady current of 10 amps, the drift velocity is\nonly about 0.024 cm/sec ! On the fast side: the Bohr model of the hydrogen\natom has the (bound) electron zipping around the nucleus at about 2 million\nmeters/sec.  And on the very fast side, some examples are: beta particles,\nwhich are emitted by some radioactive materials; and the innermost elec-\ntrons of atoms of elements having large atomic number, such as uranium.  In\nthese cases the electrons are traveling at very nearly the speed of light.\n(about 300 million meters/sec).\nRcwinther
886720
Thats simple,\nAs we rub together two surfaces, there is friction and hence the two close atoms are rubbed together which results in transfer of electrons...\nThe subs in which electrons are transfered is negatively charged (by convention electrons are supposed to have negative charge) and from which they are transfred is said to be positivly charged...
888374
Conductors allow electricity to flow through them with little resistance.  Resistors resist the flow of electricity.
508002
electricty is form of energy which is created by flow of positive charges(conventional assumption).but actually it is due to the flow ofelectrons inthe direction opposite to the flow of electricity.actually electrons do not travel with that speeed the electric field does the necessary.\n\nbut u have mentioned that matter particles cannot atttain the velocity comparable to that of light.\ni think its not correct\naccording to einstien's theory of relativity\nno particle in this universe is able to attain the velocity greater than that of light even same velocity for some.\nbut if the particle travels with a velocity comparable to that of light then the mass changes accordingly\nm=mo/sqrt(1-v^2/c^2)\nwhere mo is the rest mass of particle\nv is velocity of particle\nc is the velocity of light\nm is the mass of particle at velocity v
445231
It describes electron location in terms of probabilities.  The energy levels around a nucleus are not well-defined orbitals.  Rather, they are regions of space where an electron may be found.  Withing the orbitals, the electron's precise location can not be known.  According to Heisenberg's Uncertainty Principle, the more accurately we measure an electron's location, the more imprecise the measurement of its velocity becomes, and vice-versa.\n\nSo, the best description of an electron's location is that of an "electron cloud", which represents the region in space where an electron has the highest probability of being.
894776
According to quantum mechinics, an electron is not confined to an orbit as we know for satellites, it has a 'shell' of probability where it is most likely to be found. It also has the small but finite chance of being found inside the nucleus of the atom, so the anwer is 0.
772425
As I understand it, electrons don't travel any continuous trajectory the way large objects do.  They basically teleport from one place to another.  When they say it travels every possible trajectory, they mean there's a nonzero probability of finding it in any given place, with the probability decreasing the farther away you look.  However, I think that's still constrained by the speed of light--you won't find it a zillion miles away an instant from now.  For those trajectories, the probability of finding the electron there drops to zero.\n\nSaying an electron travels every possible trajectory is really just one of several interpretations of quantum theory.  The theory only gives us the probabilities of observing certain results; it doesn't explain what the particles actually did to produce those results.
886408
Electricity is the flow of electrons through a conductor.Movement of electrons.The voltage is the pressure that push the electrons through a conductor.When you throw a ball your hand is the voltage because is the force that push the ball,the ball is the ''electricity'' and the wind is the resistance.
46381
Well electricity needs a path to travel in. Electricity can flow in wires, or other conductors, like a plasma, which consists of charged particles; that is, the electrons have been stripped off the atoms because they are so energetic, leaving just a seething collection of positive and negative particles (said to be "ionized"). In a lightning strike, a path of charged particles extends between the cloud and the ground, or some other object near the ground like a tree or a lightning rod or building (or sometimes between one cloud and another). The electricity in lightning follows this charged path. \n\nIf you can use a powerful laser or some other technique to form an ionized path in the air, then electricity can follow that ionized path, just like it does in lightning (or in Van de Graff generator experiments).