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Searchterm 'Proton' found in 1 term [
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Proton
A proton is a basic particle located in the nucleus of an atom. The number of protons in the nucleus governs the chemical properties of that element. The positive electrical charge is equal to the negative charge of an electron and the mass is similar to that of a neutron (see also baryon). The proton belongs to the group of hadrons and is composed out of three quarks.
A hydrogen (H1) nucleus is build of one proton.
Proton beam therapy is the preferred treatment for cancers near the eye and the spinal cord.
Atom
An atom is the basic particle of matter, the smallest (~10-8cm) particle of a chemical element. Atoms consist of a nucleus with neutrons, positive charged protons and orbiting negative charged electrons. The chemical properties of elements are defined largely by the number of protons in the nucleus. The number of electrons is similar to the number of protons. An atom is ionized when the number of electrons is not equal to the number of protons; the resulting electrical charge depends on the difference between the number of protons and the number of electrons.

See Rutherford-Bohr Atom Model, Ionization.
Rutherford-Bohr Atom Model
Ernest Rutherford and Niels Bohr developed in the early 20th century a solar system like model of the atoms, in which electrons orbit around the nucleus (protons and neutrons) held by electromagnetic forces (protons - electrons).
The nucleus is held together by a very strong but short distance nuclear force, attracting all nucleons. While the protons positive charges try pushing it apart, is it the balance between protons and neutrons which decide over an elements stability.
In their model the energy of orbiting electrons is quantized into fixed values. Electrons in outer orbits are more loosely bound than the ones at inner orbits and affect an atom's chemical properties.
Erwin Schrodinger and Werner Heisenberg developed probability functions which assigns the electrons to cloud like spaces instead of fixed orbits.
Beta Particle
Henri Becquerel demonstrated beta particles in 1900. Identical with electrons is there negative charge at -1. Their mass is 549 millionths of one AMU, 1/2000 of the mass of a proton or neutron. Beta particles consist of high energetic electrons emitted by radioactive nuclei or neutrons. By the process of beta decay, one of the neutrons in the nucleus is transformed into a proton and a new atom is formed which has one less neutron but one more proton in the core. Beta decay is accompanied by the emission of a positron (the antiparticle of the electron), a positive charged antineutrino. Beta particles have a greater range of penetration than alpha particles but less than gamma rays or x-rays. The name beta was coined by Rutherford in 1897. The traveling speed of beta particles depends on their energy. Because of their small mass and charge beta particles travel deep into tissues and cause cellular damage and possible cancer.

See also Radiation Shielding.
Electron Capture
(K-capture) An unstable atom with too many protons in the nucleus, and not enough energy to emit a positron, reaches a stable state in the way, that one proton captured an electron from the atom's inner shell (K-shell) and change to a neutron. A neutrino is emitted from the atoms nucleus by this process. The atomic mass of the atom is unchanged, but the decreased number of protons transformed the atom to a different element.
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