What is Orbital: Definition and 817 Discussions

In atomic theory and quantum mechanics, an atomic orbital is a mathematical function describing the location and wave-like behavior of an electron in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. The term atomic orbital may also refer to the physical region or space where the electron can be calculated to be present, as predicted by the particular mathematical form of the orbital.Each orbital in an atom is characterized by a unique set of values of the three quantum numbers n, ℓ, and ml, which respectively correspond to the electron's energy, angular momentum, and an angular momentum vector component (the magnetic quantum number). Each such orbital can be occupied by a maximum of two electrons, each with its own projection of spin




m

s




{\displaystyle m_{s}}
. The simple names s orbital, p orbital, d orbital, and f orbital refer to orbitals with angular momentum quantum number ℓ = 0, 1, 2, and 3 respectively. These names, together with the value of n, are used to describe the electron configurations of atoms. They are derived from the description by early spectroscopists of certain series of alkali metal spectroscopic lines as sharp, principal, diffuse, and fundamental. Orbitals for ℓ > 3 continue alphabetically, omitting j (g, h, i, k, ...) because some languages do not distinguish between the letters "i" and "j".Atomic orbitals are the basic building blocks of the atomic orbital model (alternatively known as the electron cloud or wave mechanics model), a modern framework for visualizing the submicroscopic behavior of electrons in matter. In this model the electron cloud of a multi-electron atom may be seen as being built up (in approximation) in an electron configuration that is a product of simpler hydrogen-like atomic orbitals. The repeating periodicity of the blocks of 2, 6, 10, and 14 elements within sections of the periodic table arises naturally from the total number of electrons that occupy a complete set of s, p, d, and f atomic orbitals, respectively, although for higher values of the quantum number n, particularly when the atom in question bears a positive charge, the energies of certain sub-shells become very similar and so the order in which they are said to be populated by electrons (e.g. Cr = [Ar]4s13d5 and Cr2+ = [Ar]3d4) can only be rationalized somewhat arbitrarily.

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  1. G

    Writing 4 Quantum Numbers for Electron in 3D Orbital

    what are the different ways to write four quantum numbers that designate an electron in a 3d orbital
  2. V

    Addition of grav potentials / Orbital velocity

    The Attempt at a Solution I think I may of been too general with the volume in finding M_0 I'm assuming r_0 = r_M although I'm not sure why different notation is used thougj http://imageshack.us/photo/my-images/3/gravscan.jpg/
  3. S

    What is the Speed and Angle of a Comet Crossing Earth's Orbit?

    Hey, here is the problem: The minimum distance of a comet from the Sun is observed to be half the radius of the Earth’s orbit (assumed circular) and its speed at that point is twice the orbital speed v(earth) of the Earth. The Earth’s and comet’s orbits are coplanar. Find the comet’s speed...
  4. D

    Orbital Velocity due to a Dark Matter Halo

    Homework Statement I am struggling to calculate the gravitational force from a dark matter halo given that its density is given by ρ(r) = ρ0r02/r2. Once i have found the force i plan to equate it to the centripetal force, F = mv2/r, to find the velocity, v. Homework Equations Density...
  5. F

    Calculate the orbital period

    1)Use the bohr model, calculate the orbital period in eachlevel(n=1,2,3) 2) the average lifetime of the first excited level of a hydrogen atom is 1.0 10^-8 s. In the bohr model, how many orbits does an electron in the n=2 level complete before returning to the ground level? Homework...
  6. K

    Orbital angular disp. in 1 day & centrip. force and Acceleration of planets help

    As from the title, I am trying to find for Venus, Earth, and Neptune: a) the orbital angular displacement in one day in radians b) the centripetal acceleration c) the centripetal force Relevant Equations: Centrip accel: ac=v^2/r=4pie^2/T^2 Centrip force: Fc=ma=mv^2/r=4pie^2mr/T^2...
  7. W

    Orbital Angular Momentum Origin

    We know from classical mechanics that angular momentum L = r \times p depends on your choice of origin. My question is: How does this work quantum mechanically? We know we get certain eigenvalues, but does this apply only in a certain choice of origin? How do we calculate angular momentum at...
  8. J

    Derivation of formula for orbital ranges in hydrogen atom

    I almost have the answer, I'm sure there's just a minor flaw in my reasoning. Here it goes: We're given that the angular momentum of the atom is integer multiples of h-bar (n\hbar) (integer depending on the orbit). Now the centripetal force is given by F = \frac{mv^2}{r} = \frac{p^2}{mr} =...
  9. J

    Uncertainty of planetary orbital period

    I've been searching all over the place, and I cannot find any data showing the error bars of orbital periods of planets. Once source estimates the uncertainty of Jupiter to be "1 arcsec per 250 years" but I cannot find anything to back this up. Does anybody have any hints as to where I should...
  10. MikeGomez

    Energy tolerance for orbital of electrons

    An exact energy level is required to bring an electron from one orbital to another. For example with hydrogen, for an electron to go from the ground state to the third orbital requires a photon with an energy of 12.09eV. But what is the tolerance? In other words, how close to that frequency...
  11. F

    Help Determining Orbital Velocity about the Center of Mass

    Hey, so I'm new to Physics Forums as a registered member, but I've been checking this site out for what seems likes years. Homework Statement Locate the center of the mass of the Earth-moon system with respect to the center of the Earth, and then find the orbital velocity of the Earth...
  12. K

    When a star loses its mass, do the orbital radii of the planets increase?

    I remember reading an article on exoplanets which suggested that when a star loses its mass, the orbital radii of the planets orbiting it increase. Apparently this makes it easier to identify such planets as they are now further away from their star. What I would like to know is, what...
  13. D

    Orbital Hybridization - Real or Approximation

    I've been reading the book "why chemical reactions happen", and according to my understanding, it seems as though orbital hybridization is just an "approximation" and not real, as in there is no such orbital, while MO are (real). Is my understanding correct? Or are MOs also just approximations...
  14. W

    Understanding Orbital Mechanics & Elliptical Paths

    Hi. I was playing a video game where, in one level, you are in an orbit around an attractor. The game was 2D, so there's no inclination, etc. The game showed the projected path of the body around the attractor. When you used the games controls to thrust in a direction, it would show the...
  15. T

    A question on Molecular Orbital theory

    My question is as follows. When (qualitatively at least) constructing molecular orbitals for a given molecule, a few "rules" are used to construct them. I'm wondering why the "rules" exist at all. For example, it is given that orbitals must have "similar energies" (however one quantifies...
  16. N

    Effect of Tangential and Normal Forces on Orbital Velocity of Planets

    Homework Statement What effect will the tangential component of force have on the velocity of the planet? What effect will the normal component of force have on the velocity of the planet? Homework Equations The Attempt at a Solution 1. Since it is parallel to the direction of velocity, maybe...
  17. S

    The history of orbital element methods

    There seem to be several methods for calculating the orbital element. Newcomb, Laplace, Lagrange, Gauss, Olbers, ... I'm sure over time a new method came to light. However, what basically was the difference between a new method and the one it replaced? Improvements in calculations (computer)...
  18. N

    [QM] spin and orbital angular momentum: most efficient method?

    Homework Statement Consider a spin-1/2 particle whose state is |\psi \rangle = \psi_+(\textbf r) |+\rangle + \psi_-(\textbf r) |- \rangle. Let \hat{ \textbf S } be the spin observable and \hat{ \textbf L } the orbital angular momentum. We assume that \psi_+(\textbf r) = R(r) \left(...
  19. K

    Orbital mechanics: Accelrating takes you into a slower orbit?

    I'm confused by something very simple and stupid. When the mass of a satellite is tiny compared to the body being orbited, we can approximate orbital velocity as sqrt{(GM)/r} Now its obvious that as r gets larger, the orbital velocity drops. Higher orbits are slower orbits. A...
  20. A

    The Orbital of Nitrogen atom in Ammonia

    Homework Statement Experimental evidence suggests that the nitrogen atom in ammonia, NH3 , has four orbitals in the shape of a pyramid or tetrahedron. Draw an energy-level diagram to show the formation of these orbitals. (Hint: No electron promotion is required.) Homework Equations...
  21. S

    Orbital Elements-Identification of method

    Orbital Elements--Identification of method I'm looking at a book that has a method for calculating the six orbital elements. I'm attaching the relevant pages. My knowledge about orbits is limited to knowing the meaning of the six elements. What I'd like to know is where did these equations...
  22. B

    How Does the Mass of the ISS Affect Its Orbital Motion?

    I'm not asking for you to do my homework but can you help me on it?! I have no idea how to even attempt it. Any help would be greatly appreciated! The International Space Station (ISS) just celebrated its 10th anniversary of human habitation. During that time it has been orbiting the Earth...
  23. B

    Computing parabolic orbital trajectory

    I wrote a game with a rocket that orbits a planet, and you can change the orbit with thrusters. As part of it I draw the predicted orbit for the rocket. To do this I compute the eccentricity vector, then the eccentricity e, then the major and minor axis of the ellipse or hyperbola as...
  24. J

    Expectation Value of a component of Orbital Angular Momentum

    Homework Statement given a certain state |ψ> that is an eigenstate of L^2 and Lz Calculate <Lx^2> and <Lx> Homework Equations L^2|ψ> = l(l+1)h^2 Lz|ψ> = mh|ψ> Lx = YPz - ZPy The Attempt at a Solution <Lx^2> = (1/2)(h^2)[l(l+1)-(m1)^2] for Lx i got <Lx> = ∫ψ(YPz-ZPy)ψ dx
  25. D

    Books on orbital transfers, satellite control theory, dynamical systems etc

    Hey folks wondering if anyone knows some good books on the following subjects... Orbital transfers, specifically to Lagrange points with information on stable/unstable manifolds. Control theory of satellites, new to control theory so perhaps I should be looking at a general control theory...
  26. D

    Molecular Orbital energy levels

    Hi everyone I'm currently studying the MO theory and ran into some trouble understanding orbital energy levels. As I have previously read, σ bonds are stronger than ∏ bonds, therefore are lower in orbital energy. However, from the MO theory, the σ2p orbital is actually higher in energy than...
  27. B

    Show that the satellite's orbital period P at large distances (r a) is given by

    Homework Statement Assuming that the satellite's orbit is circular, show that its orbital period P at large distances (r>>a) is given by the expression: P=[(4pi/GM)^(1/2)] r^(3/2) (1-(3/4)((a^2)/(4r^2)) J(subscript2)) Comment on the behavious of P in the limits as r approaches infinity...
  28. J

    Help with satellites and planets orbital motion

    A Martian civilization is attempting to develp the capabilities for space travel. They have built a prototype satellite with a mass of 578kg that they plan to put in orbit Mars a distance of 602km above the surface of mars. A) Using the data provided, calculate the orbital velocity of the...
  29. X

    How Far Should a Satellite Be from Earth to Match the Moon's Orbital Period?

    Homework Statement A satellite is placed between the Earth and the Moon, along a straight line that connects their centers of mass. The satellite has an orbital period around the Earth that is the same as that of the Moon, 27.3 days. How far away from the Earth should this satellite be placed...
  30. teroenza

    Binary Pulsar Orbital periods.

    Hello, I am doing a very brief presentation for school on gravitational radiation and wanted to include a figure for the orbital periods of binary pulsars. I can find the rotation rates of individual pulsars on Google but can't find a figure for orbital periods of binaries. This does not...
  31. R

    Orbital Frequency of an electron in a hydrogen atom

    Homework Statement In a classical model of the hydrogen atom, the electron moves around the proton in a circular orbit of radius 0.053 nm. What is the electron's orbital frequency? What is the effective current of the electron? Homework Equations Freq * Wavelength = Speed of...
  32. J

    Solving for sp Hybrid Orbital: \Psi_{sp1}

    Homework Statement Find the other sp hybrid orbital given \Psi_{sp1} = 3\Psi_{2s} + 4\Psi_{2pz} using the orthonormal relationships. I do not know how to start the problem. if someone could help get me pointed in the right direction or help me through it I would greatly appreciate it : )
  33. U

    Measuring orbital angular momentum

    Can anyone describe an experiment that would be used to measure orbital angular momentum?
  34. mrspeedybob

    Are orbital planes generally parallel on large scales?

    The moon orbits the Earth on nearly the same plane as the Earth orbits the sun. Does this coincidence of orbital planes scale up? Do the planets in our solar system orbit on a plane that is parallel to the plane of the milky way? What about planets in other solar systems in the milky way?
  35. P

    Calculate Orbital Angular Momentum

    Satellite of mass m is moving with velocity v in a circular orbit of radius r about mass M. Find the orbital angular momentum. Know v = \sqrt{\frac{GM}{r}} Orbital angular momentum of a system is defined as the angular momentum of the center of mass of the system. Let the origin be at mass...
  36. A

    Angular speed vs. Orbital speed

    Homework Statement Consider a year to be precisely 365 days. Determine the angular speed of the Earth about the sun. If the Earth's mean distance from the sun is 1.496x1011 meters and our orbit is circular, determine our orbital speed about the sun. Homework Equations ω=Δθ/T, where ω is...
  37. S

    Carbon Compounds: Orbital & Bonding Energies Explained

    why carbon can form polymers and sillicon not? though both are tetra valent. explain this based on its orbital and bonding energies
  38. J

    What Is the Subshell Designation for l=5 in Quantum Mechanics?

    Question: How many orbitals have the values n = 6 and l = 5? Attempt: I said zero initially, since a l value of 0=s, 1=p, 2=d, 3=f, so there shouldn't be a 5? I know this is wrong now but why? What is 5= ?
  39. N

    Interference of electron waves in an atomic orbital

    I have a confusing question mainly due to my lack of understanding of Quantum Mechanics and spin! here it goes anyway... In an atomic orbital, like the 1s orbital, two electron waves with opposite spins occupy the same area of space. Now, does this mean that their waves should interfere with...
  40. Y

    What is the relativistic cause of planetary orbital rotation.

    Newtonian physics correctly predicts that a planetary orbit will be an ellipse and general relativity correctly predicts that this ellipse will rotate, as was demonstrated with mercury. The only thing that I can think of is that because the orbit is an ellipse then the planet will be...
  41. khurram usman

    How to Calculate the Energy of an Electron in the 3d Orbital of an Oxygen Atom?

    if i am to calculate the energy of an electron in the 3d orbital of oxygen atom...how i am supposed to consider the electronic configuration? i mean i can easily do so for 2p or 2s using slaters rule...because the electrons are present in those orbitals but for the 3d case where should i...
  42. K

    What is the Relationship Between Mass of Earth and Velocity of Orbit?

    Homework Statement If the Apollo vehicle is initially in a circular low Earth orbit with altitude h0 = 320 km and it is suddenly accelerated to a new (tangential) velocity of 10.8 km/s, determine the radial position, r, at apogee, the eccentricity of the new orbit and the period of this orbit...
  43. H

    Launch speed to reach a given orbital altitude

    Homework Statement [EDIT: My first statement of the problem was wrong.] 1. The space shuttle releases a satellite into a circular orbit 720 km above the Earth. How fast must the shuttle be moving (relative to Earth) when the release occurs?Homework Equations F=GmM/r^2 Fc = mv^2/rThe Attempt...
  44. S

    Molecular orbital analysis - d0 complexes

    1. Homework Statement I'm trying to perform a molecular orbital analysis of a tungsten hydride complex, (WH6) and I haven't been able to find an intuitive or basic definition for a "d0 complex". Every time I read an article about a d0 complex they tangentially mention them and then jump into...
  45. K

    Normalization constant for orbital wave functions

    Suppose I have a wavefunction ψ(r1, r2)= (∅1s(r1) ∅1p(r2) - ∅1s(r2) ∅1p(r1)) And I know that ∅1s(r1) and ∅1p(r1) are normalized. How would I go about finding the normalization constant for ψ(r1, r2)? Everywhere I look just whips out a \frac{1}{\sqrt{2}} out of nowhere...
  46. T

    Half integer orbital momentum, following Griffiths

    Hello everyone, and thanks for reading. I'm having a difficult time understanding something. On yet another attempt to deepen my quantum mechanics understanding I referred to the widely recommended book of Griffiths. I find the book indeed very good and pretty thorough in it's scope. There...
  47. L

    Orbital Transfer DeltaV Comparison for Different Orbits

    Homework Statement Assuming planar orbits, calculate the Hohmann ∆V required to transfer from a low-Earth circular orbit with radius of 1.03 Earth radii to the orbit of the Moon (assume 60 Earth radii). Compare this to the 3-maneuver strategy of (1) escaping to infinity on a parabolic orbit...
  48. J

    What Causes the Sinusoidal Waviness in UARS Orbital Altitudes?

    Please see the graph http://makanaka.files.wordpress.com/2011/09/nasa-uars1-recent_orbital_history.png My question: what exactly gives rise to the sinusoidal waviness of apogee and perigee in altitudes below 570km?
  49. T

    Discovering mass of a star and orbital period of one of two planets

    Homework Statement Two newly discovered planets follow circular orbits around a star in a distant part of the galaxy. The orbital speeds of the planets are determined to be 41.7 km/s and 55.5 km/s. The slower planet's orbital period is 8.04 years. (a) What is the mass of the star? (b)...
  50. C

    Orbital hybridization and lone electrons

    Do single non bonding electrons (i.e. on a free radical) always occupy non hybrid orbitals? For example the methyl radical has trigonal planar molecular geometry so the lone electron must occupy a p orbital. Why doesn't it occupy an sp3 orbital instead?
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