A report on Electron

Hydrogen atomic orbitals at different energy levels. The more opaque areas are where one is most likely to find an electron at any given time.
A beam of electrons deflected in a circle by a magnetic field
J. J. Thomson
Robert Millikan
The Bohr model of the atom, showing states of an electron with energy quantized by the number n. An electron dropping to a lower orbit emits a photon equal to the energy difference between the orbits.
In quantum mechanics, the behavior of an electron in an atom is described by an orbital, which is a probability distribution rather than an orbit. In the figure, the shading indicates the relative probability to "find" the electron, having the energy corresponding to the given quantum numbers, at that point.
Standard Model of elementary particles. The electron (symbol e) is on the left.
Example of an antisymmetric wave function for a quantum state of two identical fermions in a 1-dimensional box. If the particles swap position, the wave function inverts its sign.
A schematic depiction of virtual electron–positron pairs appearing at random near an electron (at lower left)
A particle with charge q (at left) is moving with velocity v through a magnetic field B that is oriented toward the viewer. For an electron, q is negative so it follows a curved trajectory toward the top.
Here, Bremsstrahlung is produced by an electron e deflected by the electric field of an atomic nucleus. The energy change E2 − E1 determines the frequency f of the emitted photon.
Probability densities for the first few hydrogen atom orbitals, seen in cross-section. The energy level of a bound electron determines the orbital it occupies, and the color reflects the probability of finding the electron at a given position.
A lightning discharge consists primarily of a flow of electrons. The electric potential needed for lightning can be generated by a triboelectric effect.
Lorentz factor as a function of velocity. It starts at value 1 and goes to infinity as v approaches c.
Pair production of an electron and positron, caused by the close approach of a photon with an atomic nucleus. The lightning symbol represents an exchange of a virtual photon, thus an electric force acts. The angle between the particles is very small.
An extended air shower generated by an energetic cosmic ray striking the Earth's atmosphere
Aurorae are mostly caused by energetic electrons precipitating into the atmosphere.
During a NASA wind tunnel test, a model of the Space Shuttle is targeted by a beam of electrons, simulating the effect of ionizing gases during re-entry.

Subatomic particle whose electric charge is negative one elementary charge.

- Electron
Hydrogen atomic orbitals at different energy levels. The more opaque areas are where one is most likely to find an electron at any given time.

186 related topics with Alpha

Overall
Photons are emitted by a cyan laser beam outside, orange laser beam inside calcite and its fluorescence

Photon

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Elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force.

Elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force.

Photons are emitted by a cyan laser beam outside, orange laser beam inside calcite and its fluorescence
Photoelectric effect: the emission of electrons from a metal plate caused by light quanta – photons.
The cone shows possible values of wave 4-vector of a photon. The "time" axis gives the angular frequency (rad⋅s−1) and the "space" axis represents the angular wavenumber (rad⋅m−1). Green and indigo represent left and right polarization
Thomas Young's double-slit experiment in 1801 showed that light can act as a wave, helping to invalidate early particle theories of light.
In 1900, Maxwell's theoretical model of light as oscillating electric and magnetic fields seemed complete. However, several observations could not be explained by any wave model of electromagnetic radiation, leading to the idea that light-energy was packaged into quanta described by . Later experiments showed that these light-quanta also carry momentum and, thus, can be considered particles: The photon concept was born, leading to a deeper understanding of the electric and magnetic fields themselves.
Up to 1923, most physicists were reluctant to accept that light itself was quantized. Instead, they tried to explain photon behaviour by quantizing only matter, as in the Bohr model of the hydrogen atom (shown here). Even though these semiclassical models were only a first approximation, they were accurate for simple systems and they led to quantum mechanics.
Photons in a Mach–Zehnder interferometer exhibit wave-like interference and particle-like detection at single-photon detectors.
Stimulated emission (in which photons "clone" themselves) was predicted by Einstein in his kinetic analysis, and led to the development of the laser. Einstein's derivation inspired further developments in the quantum treatment of light, which led to the statistical interpretation of quantum mechanics.
Different electromagnetic modes (such as those depicted here) can be treated as independent simple harmonic oscillators. A photon corresponds to a unit of energy E = hν in its electromagnetic mode.

The word quanta (singular quantum, Latin for how much) was used before 1900 to mean particles or amounts of different quantities, including electricity.

Wave functions of the electron in a hydrogen atom at different energy levels. Quantum mechanics cannot predict the exact location of a particle in space, only the probability of finding it at different locations. The brighter areas represent a higher probability of finding the electron.

Quantum mechanics

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Fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles.

Fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles.

Wave functions of the electron in a hydrogen atom at different energy levels. Quantum mechanics cannot predict the exact location of a particle in space, only the probability of finding it at different locations. The brighter areas represent a higher probability of finding the electron.
Fig. 1
Position space probability density of a Gaussian wave packet moving in one dimension in free space.
1-dimensional potential energy box (or infinite potential well)
Some trajectories of a harmonic oscillator (i.e. a ball attached to a spring) in classical mechanics (A-B) and quantum mechanics (C-H). In quantum mechanics, the position of the ball is represented by a wave (called the wave function), with the real part shown in blue and the imaginary part shown in red. Some of the trajectories (such as C, D, E, and F) are standing waves (or "stationary states"). Each standing-wave frequency is proportional to a possible energy level of the oscillator. This "energy quantization" does not occur in classical physics, where the oscillator can have any energy.
Schematic of a Mach–Zehnder interferometer.
Max Planck is considered the father of the quantum theory.
The 1927 Solvay Conference in Brussels was the fifth world physics conference.

For example, a quantum particle like an electron can be described by a wave function, which associates to each point in space a probability amplitude.

The quark content of a proton. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons.

Proton

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Stable subatomic particle, symbol, H+, or 1H+ with a positive electric charge of +1e elementary charge.

Stable subatomic particle, symbol, H+, or 1H+ with a positive electric charge of +1e elementary charge.

The quark content of a proton. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons.
Ernest Rutherford at the first Solvay Conference, 1911
Proton detected in an isopropanol cloud chamber
Protium, the most common isotope of hydrogen, consists of one proton and one electron (it has no neutrons). The term "hydrogen ion" implies that that H-atom has lost its one electron, causing only a proton to remain. Thus, in chemistry, the terms "proton" and "hydrogen ion" (for the protium isotope) are used synonymously

At sufficiently low temperatures and kinetic energies, free protons will bind to electrons.

Atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy vol. 1 (1808)

Atom

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Smallest unit of ordinary matter that forms a chemical element.

Smallest unit of ordinary matter that forms a chemical element.

Atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy vol. 1 (1808)
The Geiger–Marsden experiment: Left: Expected results: alpha particles passing through the plum pudding model of the atom with negligible deflection. Right: Observed results: a small portion of the particles were deflected by the concentrated positive charge of the nucleus.
The Bohr model of the atom, with an electron making instantaneous "quantum leaps" from one orbit to another with gain or loss of energy. This model of electrons in orbits is obsolete.
The binding energy needed for a nucleon to escape the nucleus, for various isotopes
A potential well, showing, according to classical mechanics, the minimum energy V(x) needed to reach each position x. Classically, a particle with energy E is constrained to a range of positions between x1 and x2.
3D views of some hydrogen-like atomic orbitals showing probability density and phase (g orbitals and higher are not shown)
This diagram shows the half-life (T½) of various isotopes with Z protons and N neutrons.
These electron's energy levels (not to scale) are sufficient for ground states of atoms up to cadmium (5s2 4d10) inclusively. Do not forget that even the top of the diagram is lower than an unbound electron state.
An example of absorption lines in a spectrum
Graphic illustrating the formation of a Bose–Einstein condensate
Scanning tunneling microscope image showing the individual atoms making up this gold (100) surface. The surface atoms deviate from the bulk crystal structure and arrange in columns several atoms wide with pits between them (See surface reconstruction).
Periodic table showing the origin of each element. Elements from carbon up to sulfur may be made in small stars by the alpha process. Elements beyond iron are made in large stars with slow neutron capture (s-process). Elements heavier than iron may be made in neutron star mergers or supernovae after the r-process.

Every atom is composed of a nucleus and one or more electrons bound to the nucleus.

Electric field of a positive and a negative point charge

Electric charge

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Physical property of matter that causes charged matter to experience a force when placed in an electromagnetic field.

Physical property of matter that causes charged matter to experience a force when placed in an electromagnetic field.

Electric field of a positive and a negative point charge
Diagram showing field lines and equipotentials around an electron, a negatively charged particle. In an electrically neutral atom, the number of electrons is equal to the number of protons (which are positively charged), resulting in a net zero overall charge
Coulomb's torsion balance

Electric charge can be positive or negative (commonly carried by protons and electrons respectively).

Elementary particle

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Elementary particle or fundamental particle is a subatomic particle that is not composed of other particles.

Elementary particle or fundamental particle is a subatomic particle that is not composed of other particles.

Subatomic constituents of the atom were first identified in the early 1930s; the electron and the proton, along with the photon, the particle of electromagnetic radiation.

The radioactive beta decay is due to the weak interaction, which transforms a neutron into a proton, an electron, and an electron antineutrino.

Weak interaction

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Also often called the weak force or weak nuclear force, is one of the four known fundamental interactions, with the others being electromagnetism, the strong interaction, and gravitation.

Also often called the weak force or weak nuclear force, is one of the four known fundamental interactions, with the others being electromagnetism, the strong interaction, and gravitation.

The radioactive beta decay is due to the weak interaction, which transforms a neutron into a proton, an electron, and an electron antineutrino.
A diagram depicting the decay routes due to the charged weak interaction and some indication of their likelihood. The intensity of the lines is given by the CKM parameters.
decay through the weak interaction
The Feynman diagram for beta-minus decay of a neutron into a proton, electron and electron anti-neutrino, via an intermediate heavy boson
Left- and right-handed particles: p is the particle's momentum and S is its spin. Note the lack of reflective symmetry between the states.

The fermions involved in such exchanges can be either elementary (e.g. electrons or quarks) or composite (e.g. protons or neutrons), although at the deepest levels, all weak interactions ultimately are between elementary particles.

The quark content of the neutron. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons.

Neutron

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Subatomic particle, symbol or, which has a neutral charge, and a mass slightly greater than that of a proton.

Subatomic particle, symbol or, which has a neutral charge, and a mass slightly greater than that of a proton.

The quark content of the neutron. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons.
Nuclear fission caused by absorption of a neutron by uranium-235. The heavy nuclide fragments into lighter components and additional neutrons.
Models depicting the nucleus and electron energy levels in hydrogen, helium, lithium, and neon atoms. In reality, the diameter of the nucleus is about 100,000 times smaller than the diameter of the atom.
A schematic of the nucleus of an atom indicating radiation, the emission of a fast electron from the nucleus (the accompanying antineutrino is omitted). In the Rutherford model for the nucleus, red spheres were protons with positive charge and blue spheres were protons tightly bound to an electron with no net charge. The inset shows beta decay of a free neutron as it is understood today; an electron and antineutrino are created in this process.
The Feynman diagram for beta decay of a neutron into a proton, electron, and electron antineutrino via an intermediate heavy W boson
The leading-order Feynman diagram for decay of a proton into a neutron, positron, and electron neutrino via an intermediate boson.
Institut Laue–Langevin (ILL) in Grenoble, France – a major neutron research facility.
Cold neutron source providing neutrons at about the temperature of liquid hydrogen
The fusion reaction rate increases rapidly with temperature until it maximizes and then gradually drops off. The D–T rate peaks at a lower temperature (about 70 keV, or 800 million kelvins) and at a higher value than other reactions commonly considered for fusion energy.
Transmutation flow in light water reactor, which is a thermal-spectrum reactor

The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus.

A proton is composed of two up quarks, one down quark, and the gluons that mediate the forces "binding" them together. The color assignment of individual quarks is arbitrary, but all three colors must be present; red, blue and green are used as an analogy to the primary colors that together produce a white color.

Quark

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Type of elementary particle and a fundamental constituent of matter.

Type of elementary particle and a fundamental constituent of matter.

A proton is composed of two up quarks, one down quark, and the gluons that mediate the forces "binding" them together. The color assignment of individual quarks is arbitrary, but all three colors must be present; red, blue and green are used as an analogy to the primary colors that together produce a white color.
Six of the particles in the Standard Model are quarks (shown in purple). Each of the first three columns forms a generation of matter.
Murray Gell-Mann (2007)
George Zweig (2015)
Photograph of the event that led to the discovery of the baryon, at the Brookhaven National Laboratory in 1974
Feynman diagram of beta decay with time flowing upwards. The CKM matrix (discussed below) encodes the probability of this and other quark decays.
The strengths of the weak interactions between the six quarks. The "intensities" of the lines are determined by the elements of the CKM matrix.
All types of hadrons have zero total color charge.
The pattern of strong charges for the three colors of quark, three antiquarks, and eight gluons (with two of zero charge overlapping).
Current quark masses for all six flavors in comparison, as balls of proportional volumes. Proton (gray) and electron (red) are shown in bottom left corner for scale.
A qualitative rendering of the phase diagram of quark matter. The precise details of the diagram are the subject of ongoing research.

All commonly observable matter is composed of up quarks, down quarks and electrons.

Aerial photo of the Tevatron at Fermilab, which resembles a figure eight. The main accelerator is the ring above; the one below (about half the diameter, despite appearances) is for preliminary acceleration, beam cooling and storage, etc.

Particle accelerator

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Machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams.

Machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams.

Aerial photo of the Tevatron at Fermilab, which resembles a figure eight. The main accelerator is the ring above; the one below (about half the diameter, despite appearances) is for preliminary acceleration, beam cooling and storage, etc.
Animation showing the operation of a linear accelerator, widely used in both physics research and cancer treatment.
Beamlines leading from the Van de Graaff accelerator to various experiments, in the basement of the Jussieu Campus in Paris.
Building covering the 2 mile (3.2 km) beam tube of the Stanford Linear Accelerator (SLAC) at Menlo Park, California, the second most powerful linac in the world.
A Cockcroft-Walton generator (Philips, 1937), residing in Science Museum (London).
A 1960s single stage 2 MeV linear Van de Graaff accelerator, here opened for maintenance
Modern superconducting radio frequency, multicell linear accelerator component.
Lawrence's 60 inch cyclotron, with magnet poles 60 inches (5 feet, 1.5 meters) in diameter, at the University of California Lawrence Radiation Laboratory, Berkeley, in August, 1939, the most powerful accelerator in the world at the time. Glenn T. Seaborg and Edwin McMillan (right) used it to discover plutonium, neptunium and many other transuranic elements and isotopes, for which they received the 1951 Nobel Prize in chemistry.
A magnet in the synchrocyclotron at the Orsay proton therapy center
Segment of an electron synchrotron at DESY
A Livingston chart depicting progress in collision energy through 2010. The LHC is the largest collision energy to date, but also represents the first break in the log-linear trend.

Electrons propagating through a magnetic field emit very bright and coherent photon beams via synchrotron radiation.