what are the elliptical orbits of an atom?
831362
n = 1,2,.....\n l = 0, 1, 2..... n-1\nm = -l, -(l-1)\n\nThe labels  are called quantum numbers, and made their debut in Sommerfeld's elliptical orbit model. They correspond to certain classical features of the orbit: \n\nn= sr. root of (semi major axis)\nl = orbital angular momentum\nm = orientation of the orbit
220489
The question asks specifically how many electrons can the be in the third ring of an atom. So the answer is 8 not 18. There maybe a total of 18 electrons around the atom but in the third shell there are 8. This is of course using a rather outdated concept of the atom, we should not, strictly speaking think of electrons as orbiting in shells.
44394
1. The Aufbau principle: Orbitals are occupied in order of increasing energy. 1s<2s<2p<3s<3p<4s<3d<4p<5s<4d<5p<6s<4f<5d<6p<7s<5f<6d\n\n2. The Pauli exclusion principle: Only two electrons can ocoupy an orbital and they must have opposite spin.\n\n3. Hund's rule: When there are degenerate orbitals, one electron is added to each with their spins parallel until all are half full. Then a second electron with opposite spin is added to each degenerate orbital. (See below)\n\n(Basically every space/box/circle must have an arrow pointing up before any space/box circle can have one pointing down.)\n(Everyone gets one before anyone gets two.)
970854
Use Kepler's law, which states that the orbital period squared is proportional to the cube of the orbital radius.  See http://en.wikipedia.org/wiki/Kepler%27s_law
725740
http://en.wikipedia.org/wiki/Atom
282194
In the early 20th century it was thought that electrons revolved around the nucleus in an atom very much like the way planets revolve around the sun in the solar system.  This led to some speculation that maybe atoms really were tiny solar systems (with teeny tiny people -- see the sf novel "The Girl in the Golden Atom" by Ray Cummings, 1923).  But the more detailed understanding of atoms that came about with quantum mechanics makes it clear that an atom is nothing like a solar system, and that electrons don't even have surfaces, let alone surfaces with teeny tiny people on them.
937724
Mg has 12 electrons\nwe will fill them from lower orbitals to higher\none orbital needs 2 electrons to fill in\n1s : one orbital, 12 electrons: 2e\n2s : one orbital, 10 electrons : 2e\n2p : three orbitals, 8 electrons : 6e\n3s : one orbitals, 2 electrons : 2e\n\nSeveral rules govern the placement of electrons in orbitals (electron configuration). The first dictates that no two electrons in an atom may have the same set of values of quantum numbers (this is the Pauli exclusion principle). These quantum numbers include the three that define orbitals, as well as (the hitherto unmentioned) s. Thus, two electrons may occupy a single orbital, so long as they have different values of s. However, only two electrons, because of their spin, can be associated with each orbital.\n\nAdditionally, an electron always tries to occupy the lowest possible energy state. It is possible for it to occupy any orbital so long as it does not violate the Pauli exclusion principle, but if lower-energy orbitals are available, this condition is unstable. The electron will eventually lose energy (by releasing a photon) and drop into the lower orbital. Thus, electrons fill orbitals in the order specified by the energy sequence given above.\n\nSo you will have to fill the electrons that have the same spin\nevery two electrons of an orbital have different spin but two electrons of two orbital can have the same spin\n\nyou can use a rectangle to represent for an orbital, an arrow to stand for an electron,( up or down is the spin of that electron )\ngood luck
103358
initially,the 4th orbit occupies 8 e-'s, & next orbit is filled but at times when higher levelorbit(5)get's filled (4th)it takes up 18(total)e-'s\nfurther refer text...for quantum mechanics filling is done in reff.to AUFBAU RULE.
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The energy of a satellite orbit is constant, energy defined as the sum of potential energy and kintetic energy (E = PE + KE).\n\nIn a circular orbit, both altitude and velocity are constant.  This means that the potential energy (PE) and the kintetic energy (KE) of the orbit are both constant, so there is no change in either potential energy or kinetic energy.\n\nIn an elliptical orbit, the satellite is constantly changing it's altitude, resulting in a transfer between KE and PE, even though total energy stays constant.  \n\nWork is defined as the difference between PE (or KE) at different points in the orbit.  Since the PE and KE are constantly changing, there is always work being done on a satellite in orbit.
397113
sphere, elliptic, plane, euclidean, pseudosphere, hyperbolic
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In the quantum mechanical model of the hydrogen atom, the location of the electron is expressed in terms of a probability distribution, so one speaks of the probability that an electron will be found at a particular location near a nucleus. The probability distribution, in turn, is determined by a mathematical function known as a wavefunction, denoted y. Wavefunctions for the distribution of particles are a general feature of quantum mechanics, and for electrons in atoms they are known as atomic orbitals. The name orbital is intended to express a distribution that is less precise than the explicit orbits of the Bohr model. The probability of finding an electron at a specified location is proportional to the square of the amplitude of the wavefunction at that point. Hence, the sign (positive or negative) of the orbital is not relevant to the location of the electron, because taking the square of y eliminates any negative sign it may have.
924334
Well, in terms of classical physics, an electron orbits the nucleus due to the electrical force.  But the theory of electromagnetism tells us that accelerating charged particles lose energy, and anything which is orbiting something is accelerating.  So, put these two facts together and the electron should lose energy and spiral into the nucleus.  This obviously doesn't happen (if it did, there would be no atoms...), so this was a serious problem for physics in the first decade or so of the 20th century.\n\nThe semi-classical explanation, created by a physicist named Bohr to solve the problems with the classical explanation, proposed that electrons could only be in orbits where the quantity called angular momentum (which is numerically the momentum of a particle times the radius of its orbit, or formulaicly pr=mvr=m(r^2)w where w is the angular velocity [think of it as the frequency of the orbit]) was some integer number times a constant (called h-bar).  This theory prevented the electron from falling into the nucleus of an atom, and it explained the Hydrogen atom perfectly.  But it didn't work for any other kind of atom.\n\nFinally, there's the quantum explanation, which emerged about ten/fifteen years or so after Bohr did his work.  In quantum theory particles are represented by probability distributions called wavefunctions (which is, depending on how you approach it, either a result of or the reason for Heisenburg's Uncertainty Principle; also, I'm playing a bit fast and loose with my terminology:  a wavefunction isn't a probability distribution, but if you basically square the wavefunction, that's the probability distribution).  Now, if you work out the wavefunction of an electron around a nucleus, it turns out to be constant in time, which means that it doesn't fall into the nucleus (or fly off into space or whatever else;  it stays around the nucleus as desribed by the wavefunction).  Of course, one thing which is interesting to note is that in many situations (incluing the simplest) the signle point (though not the radius) where the probability of finding the electron is the highest is actually in the nucleus.  :)  But if you found the electron there at one moment the next moment you could easily find it outside the nucleus.  It's random (as far as we know).\n\nNow, if this last confuses you or seems weird, well, it *is* quantum mechanics, and quantum mechanics is renowned for being very weird and confusing.  As to why you can never just find the electron always sitting in the nucleus of an atom, it basically has to do with the Uncertainty Principle.  If you knew that the electron definitely had to be in the same place as the nucleus at any given point of time, you couldn't know how fast it was moving very well at all, so a moment later the electron could be very far away from the nucleus (but not separated from it, as the electrical attraction would still be there and would keep the electron from escaping the nucleus altogether).\n\nI hope I've shed some light on this subject for you.
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In atomic physics, the Bohr model depicts the atom as a small, positively charged nucleus surrounded by waves of electrons in orbit — similar in structure to the solar system, but with electrostatic forces providing attraction, rather than gravity, and with waves spread over entire orbits instead of localized planets.
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I have several answers depending on your question.\n\nFirstly... Electrons are not in the nucleus. they exist in areas of space around the nucleus called orbits. They are better defined as areas of probability foor the electron to exist.\n\nSecondly... there is an s-orbital, this is a spherical orbital (or spherical region of electron existance) around the nucleus. the 1-s orbital is the closest distance an electron can approach the nucleus.\n\nEDIT: Anuj is wrong. I did a chemistry degree and i can tell you that electrons are not known to follow any preassigned orbits withing the so called 'orbit'. the word orbit is a misnomer that is often misunderstood by non-chemists and physicists.\n\nThe next orbital is 2-s, then 2-p, then 3-s, then 3-p, then  4-s, 3-d, 4-p, and then it gets confusing... hehe
130202
regular, reverse and atomic
640543
When the number of atoms of each element are equal on both sides.
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The simplest reasonable model of the atom is the Bohr model, which does tend to look like a mini solar system. In actuality, atomic structure is not so easy to define. The further you advance in chemistry, the more complex the models become, and the less they look like "mini solar systems". But they are still only reasonable attempts to visualize a very complex system, and cannot physically confine all the expected paths of the electrons' orbits.