Are electrons four dimensional entities?
823744
Yes, I guess because of electrons behave both as material particles and waves!
199784
electrons have negative charge
964379
The individual electrons do not travel in planes or anything resembling a planetary orbit.  Each electron associated with an atom "occupies" a space whose shape depend on how many other electrons are associated with the same atom.  "Occupies" is in quotes because it is only an approximation of the situation.  In a sense, any particular electron inhabits the entire universe, but with a much higher probability of being found in certain regions than in others.  If you made a really sophisticated graph of the probable locations of the electron, using an infinitely large clear crystal, and staining it some shade of black, with the darkness/opacity of the black depending on the probability of finding the electron there, you would have a picture of the space "occupied" by the electron, sometimes called an electron cloud.  For the single atom around a hydrogen atom, the cloud would be a spherical blob, very dark around the nucleus, getting somewhat transparent further from the nucleus, and getting fainter, but never completely clear as you moved further from the nucleus.  The shape of the clouds around a helium atom are somewhat like two tear drops, with their pointy ends near the nucleus.  The shapes of the clouds are different for different elements, and they are changed when an atom is part of a molecule with other atoms.  But the clouds are never planar.
362329
Consider that one electron will repel another electron (-ve does not attract -ve), each bond between a carbon and hydrogen is cased by a pair of electrons (2 electrons) so you have a total of eight electrons... this results in neutralising the charge on all the atoms.\n\nCarbon has 2s1, 2s2, 2p2 electrons which means it is theoretically 4 electrons short of its closest nobel gas (nobel gases are neutral).\nHydrogen has 1s1 electrons which means it is theoretically 1 electron short. Note that there is no p orbital in first row of periodic table.\n\nAs such each hydrogen shares its sole electron with the carbon, donating a total of 4 electrons, hence 4 hydrogens.\nThe Hydrogens get their electrons from the carbon, the carbon has 2s2 and 2p2 electrons, totalling 4 to share, 1 to each hydrogen... we do not count the s1 orbital because it is unlikely to operate in forming bonding.\n\nNow each pair repels eachother so they are furthest apart, if we do the mathematics...\nblah blah...\nWe end up with an optimum angle of 107.5 degrees between eah hydrogen, any more than that and a different hydrogen will repel it back, and likewise if less. this forms a 'tetrahedral' shape.\n\nIf you were to switch a hydrogen with another element... say chlorine, to produce CH3Cl (Chloro-methane) then the hydrogens (being the smaller atoms with less electrons) will be pushed further from the chlorine which will tend to determine the molecule's appearance. Ch3Cl is not a perfect tetrahedral as its angles will not equal 107.5, but we still call it that for simplicity's sake.\n\nI recommend that for further information do a search on the following phrases:\n\nVSEPR\nValence Shell Electron Pair Repulsion theory\nMolecular geometry\nMethane\nOrganic Chemistry
910896
The answer comes from quantum mechanics and involves some graduate level math. \n\nThat being said the general rule is that a Principal quantum number can have up to 2n^2 electrons.
779218
Here's a great and simple explaination from Wikiopedia: \n\nIn atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (eg, a crystal).\n\nLike other elementary particles, the electron is subject to the laws of quantum mechanics, and exhibits both particle-like and wave-like properties. Formally, the quantum state of a particular electron is defined by its wavefunction, a complex-valued function of space and time. According to the Copenhagen interpretation of quantum mechanics, a particular electron is both "nowhere at all" and "everywhere all at once" until an act of measurement causes it to be detected. The probability that the act of measurement will detect the electron at a particular point in space is proportional to the square of the absolute value of the wavefunction at that point.\n\nElectrons are able to jump from one energy level to another by emission or absorption of a quantum of energy, in the form of a photon. Because of the Pauli exclusion principle, no more than two electrons may exist in a given atomic orbital; therefore an electron may only leap to another orbital if there is a vacancy there.\n\nKnowledge of the electron configuration of different atoms helps us understand the structure of the periodic table of elements. The concept is also useful for describing the chemical bonds that hold molecules together. And in a macro sense this same idea helps explain the peculiar properties of lasers and semiconductors\n\n\nThe other links are also good sources for review and expaination\n\nGood luck
663495
7\nf sublevel, containing seven f orbitals, which can hold a maximum of 14 electrons. Thus, the fourth level can hold up to 32 electrons: 2 in the s orbital, 6 in the three p orbitals, 10 in the five d orbitals, and 14 in the seven f orbitals.
1132675
Physics believes that there are 12 dimensions. The Bible seems to back that up.\n\nWe know four dimensions: height, width, length and time.
398026
it's a wormhole that takes you to another dimension, i guess.\n\nthat means it will take you from a 4-d world to a 8-d or \n2-d world.\n\nyou could go to the inside of an electron, if this us possible.
833754
the steric number = number of atoms attached + number of lone pairs of electrons.  For water, you have 2 H atoms attached to the oxygen + 2 lone pairs.  That makes 4.  \n\n4 is defined as a tetrahedron.  However, 2 of the corners of that tetrohedron are filled with electron pairs, not atoms, so they do not determine the geometric shape, which is bent.
446372
You proffered the example of XeF4.  Now the Lewis structure for XeF4 gives an expanded octet, viz: AX4E2, where A represents the central atom (Xe) in this example; X represents a shared pair of electrons; and E represents an unshared pair.  Thus for XeF4 we have 4 shared pairs and 2 unshared pairs, i.e. 6 pairs.  \n\nNow whatever the principal energy level(n), there is 1 s orbital; and for n=2 and higher, there are 3 p orbitals; and for n=3 and higher there are 5 d orbitals. For n=4 and higher there are 7 f orbitals.\n\nNow considering XeF4 hybridization, for the 6 pairs of electrons there will be 6 orbitals [each orbital holds a maximum of two electrons with opposite spin]. That means sp3d2 hybridization.  That is the one s orbital, the three p orbitals and two of the five d orbitals form six sp3d2 orbitals.  Of course, we are talking here about valence shell electrons.  How would these orbitals fill?  Well, electrons are added to orbitals such that electrons with the same spin are added until there are no more empty orbitals, then the orbitals with one electron fill (i.e. add a second electron) by acquiring an electron of opposite spin.\n\nThis gives XeF4 sp3d2 hybrid orbitals and an octahedron orientation. \n\nConsidering the Lewis structure for water, as another example, we obtain a AX2E2 form. Thus sp3 hydrid orbitals and a tetrahedron orientation. The 4 hybrid orbitals come from 1 s and 3 p atomic orbitals.
1136639
In the Standard Model, quarks, electrons and the like are considered to be pointlike. This gives problems at short distances where for instance the electromagnetic force between two of them becomes infinite.\n\nThe basic idea of stringtheory is that the fundamental constituents of matter are strings of a length of order of 10^35 m which vibrate at specific frequencies. However, the simplest string theories give more problems then they solve and consistent theories requires more then four dimensions. \n\nMembranes take the idea even further.  The particles are represented by vibrating surfaces and higher dimensional objects.
13297
Atoms have a nucleus ( composed of protons and neutrons) and a cloud of electrons. The number of the different components varies between different elements.\n\nElectrons can only have specific energy levels in an atom - that is the energy is not continious but quantized. This is different from, say, the solar system, because a planet could theoretically be in any orbit. But we know from quantum mechanics (and many, many experiments) that electons can only occupy certain "orbits."\n\nSometimes an electron can be bumped into a higher orbit (the higher orbits have less energy, because they are not as tightly bound) or kicked out of the atom altogether. If a second electron moves into the spot it will release energy as it falls into that level.\n\nHydrogen is the easiest element to study. The nucleus is a single proton, and it can have only one electron. The different energy levels can be illustrated like this:\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/hyde.html#c2\n(though in reality electrons don't travel on nice orbits)\n\nIf an electron in the second lowest level does a "quantum leap" to the very lowest, it will emit energy - light - at a very specific frequency. In this case 656 nanometers, which is red. If, on the other hand, an electron falls from the 3rd level down to the 1st level the emitted light is blue.\n\nA "spectrum" will show all of these distinct levels, with the brighter ones being the most common. This shows the spectrum of hydrogen with a diagram of the quantum leaps:\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/hyde.html#c4\n\nIn other atoms it becomes more complex, not every jump is allowed, and in the precense of a magnetic field a "fine structure" is seen in the spectrum, as some of the main lines look double.\n\nThe result of all of this is that each different atom will give a different characteristic spectrum. So, you can use this to identify different elements in anything from crime scene samples to distant galaxies.
902950
Basically the same as the model of the hydrogen atom, but with more of everything!\nEach of the electrons follows it's own path, which are all perfectly circular orbits and are arranged so as to have the maximum distance between orbits possible. I'm not sure about the energy levels, or if the orbits all have the same radius...
335734
I consider humans as being 4 dimensional and existing in a 4d world...unfortunately we cannot fully interact with the 4th dimension (I guess we are temporal retards)......but that aside......\n\nYour 2d and 3d examples are correct because they are both physical dimensions.\n\nHowever, a 4d observer would not be able to touch every molecule of a 3d world which he was observing........this is because the 4th dimension is temporal rather than physical....he would still have physical boundaries.\n\nHe would be able to interact with a 3d world in the same physical way as we would, but he could do it in the past or future....which we cannot unfortunately....we are stuck in our present...moving ever forward in the temporal plane.\n\nPhysically, he would also be able to interact with his 4d world in the same way as a 3d observer interacts with their 3d world (and it would simply appear normal to him).\nTemporally, he could interact with his 4d world in the same way as he could interact with a 3d world...he could travel in time, but would remain constrained by physical barriers.\n\n5d.....well.....what is your definition of the 5th dimension ?\n\nProbably somewhat different to mine !!!
360394
A more generic term for the components of an atom is "sub-atomic particles."  I think that's the answer you're looking for.
184932
Nobody knows WHY electrons only exist in descrete rings.\nThe quantum physics only describles the facts but does not explain why.