A report on Atom, Atomic nucleus, Proton and Strong interaction

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

A model of the atomic nucleus showing it as a compact bundle of the two types of nucleons: protons (red) and neutrons (blue). In this diagram, protons and neutrons look like little balls stuck together, but an actual nucleus (as understood by modern nuclear physics) cannot be explained like this, but only by using quantum mechanics. In a nucleus that occupies a certain energy level (for example, the ground state), each nucleon can be said to occupy a range of locations.

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.

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

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.

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.

Ernest Rutherford at the first Solvay Conference, 1911

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

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 This model of electrons in orbits is obsolete.

Proton detected in an isopropanol cloud chamber

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

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

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

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.

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.

- Atomic nucleus

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

- Strong interaction

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

- Proton

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

- Atom

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

- Atom

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.

- Strong interaction

The nucleus of an atom consists of neutrons and protons, which in turn are the manifestation of more elementary particles, called quarks, that are held in association by the nuclear strong force in certain stable combinations of hadrons, called baryons.

- Atomic nucleus

The two up quarks and one down quark of a proton are held together by the strong force, mediated by gluons.

- Proton

The quarks are held together by the strong interaction (or strong force), which is mediated by gluons.

- Atom

4 related topics with Alpha

Neutron

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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 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.

Protons and neutrons constitute the nuclei of atoms.

Like protons, the quarks of the neutron are held together by the strong force, mediated by gluons.

Hadron

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

In particle physics, a hadron ("stout, thick") is a composite subatomic particle made of two or more quarks held together by the strong interaction.

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.

Almost all "free" hadrons and antihadrons (meaning, in isolation and not bound within an atomic nucleus) are believed to be unstable and eventually decay into other particles.

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.

Because they are composed of quarks, baryons participate in the strong interaction, which is mediated by particles known as gluons.

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

The nuclear force binds nucleons into atomic nuclei.

By this new model, the nuclear force, resulting from the exchange of mesons between neighboring nucleons, is a residual effect of the strong force.