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Electron cloud is a term used- if not originally coined- by the nobelaurate and acclaimed educator Richard Feynman in The Feynman Lectures on Physics, for discussing "exactly what is an electron?". This intuitive model provides a simplified way of visualizing an electron as a solution of the Schrödinger equation. In the electron cloud analogy, the probability density for the electron, or wavefunction, is likened to a small cloud moving around the atomic or molecular nucleus, with the brightness of the cloud proportional to the probability density. Experimental evidence suggests that the probability density is not just a theoretical model for the uncertainty in the location of the electron, but rather that it reflects the actual state of the electron. This carries an enormous philosophical implication, that the universe's evolution is fundamentally uncertain. Richard Phillips Feynman (May 11, 1918 – February 15, 1988; surname pronounced ) was an American physicist known for expanding the theory of quantum electrodynamics, the physics of the superfluidity of supercooled liquid helium, and particle theory. ...
The Feynman Lectures on Physics, by Richard Feynman, is perhaps his most accessible technical work for anyone with an interest in physics and today is considered to be the classic introduction to modern physics, including lectures on mathematics, electromagnetism, Newtonian physics, quantum physics, and even the relation of physics to...
e- redirects here. ...
In physics, the Schrödinger equation, proposed by the Austrian physicist Erwin Schrödinger in 1925, describes the space- and time-dependence of quantum mechanical systems. ...
This article discusses the concept of a wavefunction as it relates to quantum mechanics. ...
A semi-accurate depiction of the helium atom. ...
This model evolved from the earlier Bohr model which likened an electron orbiting an atomic nucleus to a planet orbiting the sun. The electron cloud formulation better explains many observed phenomena, including the double slit experiment, the periodic table and molecular bonding, and atomic interactions with light. Although lacking in certain details, the intuitive model roughly allows for wave-particle duality, electron behaviour that is both "wavy", as per the left side of E=mc2, and "lumpy", as per the right side (although the equation's founder Einstein was troubled by the probabilistic nature of the theory). The Bohr model of the hydrogen atom, where negatively charged electrons confined to atomic shells encircle a small positively charged atomic nucleus, and that an electron jump between orbits must be accompanied by an emitted or absorbed amount of electromagnetic energy hν. The orbits that the electrons travel in are...
In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ...
The double-slit experiment consists of letting light diffract through two slits producing fringes on a screen. ...
The periodic table of the chemical elements is a tabular method of displaying the chemical elements, first devised in 1869 by the Russian chemist Dmitri Mendeleev. ...
In physics, wave-particle duality holds that light and matter exhibit properties of both waves and of particles. ...
Albert Einsteins equation E=mc² is among the best-known equations of all time. ...
Einstein redirects here. ...
In the electron cloud model, rather than following fixed orbits, electrons bound to an atom are observed more frequently in certain areas around the nucleus called orbitals. The electron cloud can transition between electron orbital states, and each state has a characteristic shape and energy, all predicted as the Schrödinger equation has infinitely many solutions. Experimental results motivated this conceptual refinement of the Bohr model. The famous double slit experiment demonstrates the random behaviour of electrons, as free electrons shot through a double slit are seen to materialize at random locations with wavelike interference. Heisenberg's uncertainty principle accounts for this and, taken together with the double slit experiment, implies that an electron behaves more like a smear of infinitesimal pieces, or "cloud", each piece moving somewhat independently as in a churning cloud. These pieces can be forced to coincide at an isolated point in time, but then they all must move relative to each other at an increased spread of rates to conserve the "uncertainty". Certain physical interactions of this wave-like electron, such as observing which slit an electron passes through in the double-slit experiment, require this coincidence of pieces into a lump-like particle. In such an interaction the electron "materializes", "lumps", or "is observed" at the location of one of the infinitesimal pieces, apparently randomly chosen. Although the cloud shrinks to the accuracy of the observation (if observed by light for example the wavelength of the light limits the accuracy), its momentum spread increases so that Heisenberg's uncertainty principle is still valid. The term orbital has several meanings: In physics and chemistry it is used to describe an atomic electron configuration, see also molecular orbital and atomic orbital. ...
In quantum physics, the Heisenberg uncertainty principle, sometimes called the Heisenberg indeterminacy principle, expresses a limitation on accuracy of (nearly) simultaneous measurement of observables such as the position and the momentum of a particle. ...
Unlike the fixed orbit conceptualization, the electron cloud is not predicted to collapse into a proton while emitting a photon to minimize the sum of electric potential and kinetic energies, since the "cloud" would gain too much kinetic energy, as required to conserve uncertainty. The smear obeys Schrödinger's equation (see also Erwin Schrödinger), which has discrete solutions at differing energy levels. Each of these solutions can be depicted in gray scale, loosely resembling a cloud. This predicts light interactions with an atom, as electrons transition between these cloud states by absorbing or emitting photons equivalent to the difference, or quantum, in their energy. Also, the periodic table is predicted as an electron is added to the lowest unoccupied energy orbital in progressing from hydrogen to helium, and to subsequent elements, with properties that match those predicted by the orbital solutions to Schrödinger's equation. In physics, the Schrödinger equation, proposed by the Austrian physicist Erwin Schrödinger in 1925, describes the time-dependence of quantum mechanical systems. ...
Erwin Rudolf Josef Alexander Schrödinger (August 12, 1887 – January 4, 1961) was an Austrian physicist who achieved fame for his contributions to quantum mechanics, especially the Schrödinger equation, for which he received the Nobel Prize in 1933. ...
The term "electron cloud" carries a connotation that simple language facilitates progress especially in areas such as small scale physics where everyday experience does not extrapolate well. Additional experiments, such as the behaviour of electrons in high speed accelerators, have resulted in more sophisticated models including quantum electrodynamics and superstring theories, although the most exciting discoveries are certainly ahead of us in, as Feynman put it, "the greatest adventure that the human mind has ever begun". Quantum electrodynamics (QED) is a relativistic quantum field theory of electromagnetism. ...
Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. ...
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