A report on Neutron, Proton and Atom

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.

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.

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

Nuclear fission caused by absorption of a neutron by uranium-235. The heavy nuclide fragments into lighter components and additional neutrons.

Ernest Rutherford at the first Solvay Conference, 1911

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.

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.

Proton detected in an isopropanol cloud chamber

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 This model of electrons in orbits is obsolete.

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.

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

The binding energy needed for a nucleon to escape the nucleus, for various isotopes

The Feynman diagram for beta decay of a neutron into a proton, electron, and electron antineutrino via an intermediate heavy W boson

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.

The leading-order Feynman diagram for decay of a proton into a neutron, positron, and electron neutrino via an intermediate boson.

3D views of some hydrogen-like atomic orbitals showing probability density and phase (g orbitals and higher are not shown)

Institut Laue–Langevin (ILL) in Grenoble, France – a major neutron research facility.

This diagram shows the half-life (T½) of various isotopes with Z protons and N neutrons.

Cold neutron source providing neutrons at about the temperature of liquid hydrogen

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.

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.

An example of absorption lines in a spectrum

Transmutation flow in light water reactor, which is a thermal-spectrum reactor

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.

The neutron is a subatomic particle, symbol or, which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton.

- Neutron

Protons and neutrons constitute the nuclei of atoms.

- Neutron

Its mass is slightly less than that of a neutron and the proton-to-electron mass ratio makes it 1836 times the mass of an electron.

- Proton

One or more protons are present in the nucleus of every atom.

- Proton

The nucleus is made of one or more protons and a number of neutrons.

- Atom

16 related topics with Alpha

Atomic nucleus

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A figurative depiction of the helium-4 atom with the electron cloud in shades of gray. In the nucleus, the two protons and two neutrons are depicted in red and blue. This depiction shows the particles as separate, whereas in an actual helium atom, the protons are superimposed in space and most likely found at the very center of the nucleus, and the same is true of the two neutrons. Thus, all four particles are most likely found in exactly the same space, at the central point. Classical images of separate particles fail to model known charge distributions in very small nuclei. A more accurate image is that the spatial distribution of nucleons in a helium nucleus is much closer to the helium electron cloud shown here, although on a far smaller scale, than to the fanciful nucleus image. Both the helium atom and its nucleus are spherically symmetric.

The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.

Electron

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Subatomic particle whose electric charge is negative one elementary charge.

A beam of electrons deflected in a circle by a magnetic field

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.

The electron's mass is approximately 1836 times smaller than that of the proton.

The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavelength for a given energy.

The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without, allows the composition of the two known as atoms.

Hydrogen

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Chemical element with the symbol H and atomic number 1.

Depiction of a hydrogen atom with size of central proton shown, and the atomic diameter shown as about twice the Bohr model radius (image not to scale)

Hydrogen gas is colorless and transparent, here contained in a glass ampoule.

Phase diagram of hydrogen. The temperature and pressure scales are logarithmic, so one unit corresponds to a 10x change. The left edge corresponds to 105 Pa, which is about atmospheric pressure.

Hydrogen emission spectrum lines in the visible range. These are the four visible lines of the Balmer series

NGC 604, a giant region of ionized hydrogen in the Triangulum Galaxy

For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons.

A composite particle proton is made of two up quark and one down quark, which are elementary particles

Subatomic particle

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The Standard Model classification of particles

In physical sciences, a subatomic particle is a particle that composes an atom.

According to the Standard Model of particle physics, a subatomic particle can be either a composite particle, which is composed of other particles (for example, a proton, neutron, or meson), or an elementary particle, which is not composed of other particles (for example, an electron, photon, or muon).

Deuterium

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One of two stable isotopes of hydrogen (the other being protium, or hydrogen-1).

Ionized deuterium in a fusor reactor giving off its characteristic pinkish-red glow

Emission spectrum of an ultraviolet deuterium arc lamp

The "Sausage" device casing of the Ivy Mike H bomb, attached to instrumentation and cryogenic equipment. The 20-ft-tall bomb held a cryogenic Dewar flask with room for 160 kg of liquid deuterium.

The nucleus of a deuterium atom, called a deuteron, contains one proton and one neutron, whereas the far more common protium has no neutrons in the nucleus.

Hadron

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Composite subatomic particle made of two or more quarks held together by the strong interaction.

All types of hadrons have zero total color charge (three examples shown)

Most of the mass of ordinary matter comes from two hadrons: the proton and the neutron, while most of the mass of the protons and neutrons is in turn due to the binding energy of their constituent quarks, due to the strong force.

Protons and neutrons (which make the majority of the mass of an atom) are examples of baryons; pions are an example of a meson.

Muon

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Elementary particle similar to the electron, with an electric charge of −1 e and a spin of 1⁄2, but with a much greater mass.

Cosmic ray muon passing through lead in cloud chamber

As with the decay of the non-elementary neutron (with a lifetime around 15 minutes), muon decay is slow (by subatomic standards) because the decay is mediated only by the weak interaction (rather than the more powerful strong interaction or electromagnetic interaction), and because the mass difference between the muon and the set of its decay products is small, providing few kinetic degrees of freedom for decay.

They were negatively charged but curved less sharply than electrons, but more sharply than protons, for particles of the same velocity.

The muon was the first elementary particle discovered that does not appear in ordinary atoms.

The nucleus of a helium atom. The two protons have the same charge, but still stay together due to the residual nuclear force

Strong interaction

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The fundamental couplings of the strong interaction, from left to right: gluon radiation, gluon splitting and gluon self-coupling.

An animation of the nuclear force (or residual strong force) interaction between a proton and a neutron. The small colored double circles are gluons, which can be seen binding the proton and neutron together. These gluons also hold the quark/antiquark combination called the pion together, and thus help transmit a residual part of the strong force even between colorless hadrons. Anticolors are shown as per [[:File:Quark Anticolors.svg|this diagram]]. For a larger version, click here

Strong interaction or strong nuclear force is a fundamental interaction that confines quarks into proton, neutron, and other hadron particles.

On a larger scale (of about 1 to 3 femtometer), it is the force (carried by mesons) that binds protons and neutrons (nucleons) together to form the nucleus of an atom.

Force (in units of 10,000 N) between two nucleons as a function of distance as computed from the Reid potential (1968). The spins of the neutron and proton are aligned, and they are in the S angular momentum state. The attractive (negative) force has a maximum at a distance of about 1 fm with a force of about 25,000 N. Particles much closer than a distance of 0.8 fm experience a large repulsive (positive) force. Particles separated by a distance greater than 1 fm are still attracted (Yukawa potential), but the force falls as an exponential function of distance.

Nuclear force

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Corresponding potential energy (in units of MeV) of two nucleons as a function of distance as computed from the Reid potential. The potential well is a minimum at a distance of about 0.8 fm. With this potential nucleons can become bound with a negative "binding energy."

Comparison between the Nuclear Force and the Coulomb Force.
a - residual strong force (nuclear force), rapidly decreases to insignificance at distances beyond about 2.5 fm,
b - at distances less than ~ 0.7 fm between nucleons centers the nuclear force becomes repulsive,
c - coulomb repulsion force between two protons (over 3 fm force becomes the main),
d - equilibrium position for proton - proton,
r - radius of a nucleon (a cloud composed of three quarks).
Note: 1 fm = 1E-15 m.

A simplified Feynman diagram of a strong proton–neutron interaction mediated by a virtual neutral pion. Time proceeds from left to right.

An animation of the interaction. The colored double circles are gluons. Anticolors are shown as per [[:File:Quark Anticolours.png|this diagram]] ([[:File: Nulcear Force anim.gif|larger version]]).

The same diagram as that above with the individual quark constituents shown, to illustrate how the fundamental strong interaction gives rise to the nuclear force. Straight lines are quarks, while multi-colored loops are gluons (the carriers of the fundamental force). Other gluons, which bind together the proton, neutron, and pion "in flight", are not shown.

The nuclear force (or nucleon–nucleon interaction, residual strong force, or, historically, strong nuclear force) is a force that acts between the protons and neutrons of atoms.

Baryon

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Type of composite subatomic particle which contains an odd number of valence quarks .

Combinations of three u, d or s quarks forming baryons with a spin-1⁄2 form the uds baryon octet

For example, a proton is made of two up quarks and one down quark; and its corresponding antiparticle, the antiproton, is made of two up antiquarks and one down antiquark.

The most familiar baryons are protons and neutrons, both of which contain three quarks, and for this reason they are sometimes called triquarks.

These particles make up most of the mass of the visible matter in the universe and compose the nucleus of every atom.