A Bohr model of the hydrogen atom, showing an electron jumping between fixed orbits and emitting a photon of energy with a specific frequency

Thus, the planetary model of the atom was discarded in favor of one that described atomic orbital zones around the nucleus where a given electron is most likely to be observed.

As far as atoms and their electron shells were concerned, not only did this yield a better overall description, i. e. the atomic orbital model, but it also provided a new theoretical basis for chemistry

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 microscopic behavior of electrons in matter.

) A state is actually a function of the coordinates of all the electrons, so that their motion is correlated, but this is often approximated by this independent-particle model of products of single electron wave functions.

With de Broglie's suggestion of the existence of electron matter waves in 1924, and for a short time before the full 1926 Schrödinger equation treatment of hydrogen like atom, a Bohr electron " wavelength " could be seen to be a function of its momentum, and thus a Bohr orbiting electron was seen to orbit in a circle at a multiple of its half-wavelength ( this historically incorrect Bohr model is still occasionally taught to students ).

In our current understanding of physics, the Bohr model is called a semi-classical model because of its quantization of angular momentum, not primarily because of its relationship with electron wavelength, which appeared in hindsight a dozen years after the Bohr model was proposed.

The quantum number n first appeared in the Bohr model where it determines the radius of each circular electron orbit.

One model that estimates the properties of an electron gas at absolute zero in metals is the Fermi gas.

As predicted by the VSEPR model of electron pair repulsion, the molecular geometry of alkenes includes bond angles about each carbon in a double bond of about 120 °.

The plum pudding model of the atom by J. J. Thomson, who discovered the electron in 1897, was proposed in 1904 before the discovery of the atomic nucleus in order to add the electron to the atomic model.

These orbits were stabilized in the model by the fact that when an electron moved farther from the center of the positive cloud, it felt a larger net positive inward force, because there was more material of opposite charge, inside its orbit ( see Gauss's law ).

Paul Drude proposed the first theoretical model for a classical electron moving through a metallic solid.

However, despite the success of Drude's free electron model, it had one notable problem, in that it was unable to correctly explain the electronic contribution to the specific heat of metals, as well as the temperature dependence of resistivity at low temperatures.

Drude's classical model was augmented by Felix Bloch, Arnold Sommerfeld, and independently by Wolfgang Pauli, who used quantum mechanics to describe the motion of a quantum electron in a periodic lattice.

In this model, the electrons were free to rotate within the blob or cloud of positive substance.

Nesvorny and Jenniskens ' first fully dynamical model of the zodiacal cloud demonstrated that only if the dust was released in orbits that approach Jupiter, is it stirred up enough to explain the thickness of the zodiacal dust cloud.

Clouds remain one of the largest uncertainties in future projections of climate change by global climate models, owing to the physical complexity of cloud processes and the small scale of individual clouds relative to the size of the model computational grid.

* Client – server model ( 2-tier, n-tier, Peer-to-peer, cloud computing all use this model )

Defensesystems. com, DISA ' private cloud ' serves as personnel system: Air Force Personnel Center to shift applications to software-as-a-service model.

The point cloud of a manufactured part can be aligned to a CAD model ( or even another point cloud ), and compared to check for differences.

In order to model weather systems, atmospheric physicists employ elements of scattering theory, wave propagation models, cloud physics, statistical mechanics and spatial statistics which are highly mathematical and related to physics.

In the plum pudding model, proposed by J. J. Thomson in 1904, the atom is composed of electrons surrounded by a ' cloud ' of positive charge to balance the electrons ' negative charge.

This model typically applies when charge carriers have been emitted from some region of a solid — the cloud of emitted carriers can form a space charge region if they are sufficiently spread out, or the charged atoms or molecules left behind in the solid can form a space charge region.

In cloud computing model web applications are software as a service ( SaaS ).

In this new model, data and tools are no longer stored on the single system, instead they are stored someplace else, “ in the cloud ”.

The cloud metaphor is replacing the desktop model ; it remains to be seen how many of the common desktop icons ( file, file folder, trashcan, inbox, filing cabinet ) find a place in this new metaphor.

According to the currently accepted model of star formation, sometimes referred to as the nebular hypothesis, a star is formed by the gravitational collapse of a pocket of matter within a giant molecular cloud.

However, some scholars have recently rehabilitated Grosch's law, looking at the history of cloud computing and claiming that " Grosch was wrong about the cost model of

:* Electron cloud model following the development of quantum mechanics in 1925 and the eventual atomic orbital models derived from the quantum mechanical solution to the hydrogen atom.

It has launched cloud computing services, offering product under its infrastructure as a server ( Iaas ) and software as a service ( Saas ) portfolio, which enables enterprises, mainly small and medium, a cost-effective IT infrastructure and application on pay-per-user model.

The dynamic model balances the contributions from various sensors, various partial error models and finally comprises in a sharp virtual depiction as a map with the location and heading of the robot as some cloud of probability.

In order to model weather systems, atmospheric physicists employ elements of scattering theory, wave propagation models, cloud physics, statistical mechanics and spatial statistics which are highly mathematical and related to physics.

In 1911, Ernest Rutherford gave a model of the atom in which a central core held most of the atom's mass and a positive charge which, in units of the electron's charge, was to be approximately equal to half of the atom's atomic weight, expressed in numbers of hydrogen atoms.

Moseley, after discussions with Bohr who was at the same lab ( and who had used Van den Broek's hypothesis in his Bohr model of the atom ), decided to test Van den Broek and Bohr's hypothesis directly, by seeing if spectral lines emitted from excited atoms fit the Bohr theory's demand that the frequency of the spectral lines be proportional to a measure of the square of Z.

The principles of quantum mechanics were used to successfully model the atom.

Rutherford interpreted the gold foil experiment as suggesting that the positive charge of a heavy gold atom and most of its mass was concentrated in a nucleus at the center of the atom — the Rutherford model.

These results refined Ernest Rutherford's and Antonius Van den Broek's model, which proposed that the atom contains in its nucleus a number of positive nuclear charges that is equal to its ( atomic ) number in the periodic table.

In 1926, Erwin Schrödinger used this idea to develop a mathematical model of the atom that described the electrons as three-dimensional waveforms rather than point particles.

The study of these lines led to the Bohr atom model and to the birth of quantum mechanics.

Shortly after, in 1913, Rutherford's postdoctoral student Niels Bohr proposed a new model of the atom, wherein electrons orbited the nucleus with classical periods, but were only permitted to have discrete values of angular momentum, quantized in units h / 2π.

The Bohr model of the atom fixed the problem of energy loss from radiation from a ground state ( by declaring that there was no state below this ), and more importantly explained the origin of spectral lines.

The Bohr model | Rutherford – Bohr model of the hydrogen atom.

The significance of the Bohr model was that it related the lines in emission and absorption spectra to the energy differences between the orbits that electrons could take around an atom.

Constant angular momentum is extremely useful when dealing with the orbits of planets and satellites, and also when analyzing the Bohr model of the atom.

A schematic presentation of the plum pudding model of the atom.

In this model, the atom is composed of electrons ( which Thomson still called " corpuscles ", though G. J. Stoney had proposed that atoms of electricity be called electrons in 1894 ) surrounded by a soup of positive charge to balance the electrons ' negative charges, like negatively charged " plums " surrounded by positively charged " pudding ".

With this model, Thomson abandoned his earlier " nebular atom " hypothesis in which the atom was composed of immaterial vortices.

to imply a very small nucleus of the atom containing a very high positive charge ( in the case of gold, enough to balance about 100 electrons ), thus leading to the Rutherford model of the atom.