subatomic particle

Examples of subatomic particle in the following topics:

• Particle Accelerator

  • A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds within well-defined beams.
  • While current particle accelerators are focused on smashing subatomic particles together, early particle accelerators would smash entire atoms together, inducing nuclear fusion and thus nuclear transmutation.
  • This occurs either through nuclear reactions in which an outside particle reacts with a nucleus, which can be supplied by a particle accelerator, or through radioactive decay, where no outside particle is needed.
  • Since colliders can give evidence on the structure of the subatomic world, accelerators were commonly referred to as atom smashers in the 20th century.
  • Despite the fact that most accelerators (with the exception of ion facilities) actually propel subatomic particles, the term persists in popular usage when referring to particle accelerators in general.

• Radiation

  • Subatomic particles may be more or less penetrating, and may be generated by a radioisotope or a device, depending on the type of particle.
  • Irradiation with particles may make materials radioactive, depending on the type of particles, their energy, and the type of target material: neutrons and very high-energy particles can make materials radioactive but have good penetration, whereas lower energy particles (other than neutrons) cannot make materials radioactive, but have poorer penetration.

• Nuclear Stability

  • An atom with an unstable nucleus, called a radionuclide, is characterized by excess energy available either for a newly created radiation particle within the nucleus or via internal conversion.
  • Radioactive decay results in the emission of gamma rays and/or subatomic particles such as alpha or beta particles, as shown in .
  • An atomic nucleus emits an alpha particle and thereby transforms ("decays") into an atom with a mass number smaller by four and an atomic number smaller by two.

• Early Ideas about Atoms

  • The Greeks called these particles atomos, meaning indivisible, and the modern word "atom" is derived from this term.
  • Democritus proposed that different types and combinations of these particles were responsible for the various forms of matter.
  • Like the early philosophers, Dalton's theories were not popularly accepted for much of the 19th century, but his ideas have since been accepted, with amendments addressing subatomic particles and the interconversion of energy and mass.

• The Discovery of the Parts of the Atom

  • Modern scientific usage denotes the atom as composed of constituent particles: the electron, the proton and the neutron.
  • Though originally viewed as a particle that cannot be cut into smaller particles , modern scientific usage denotes the atom as composed of various subatomic particles.
  • His explanation for this was the existence of a neutrally charged particle within the atomic nucleus.
  • In 1932, James Chadwick showed uncharged particles in the radiation he used.
  • These particles had a similar mass as protons, but did not have the same characteristics as protons.

• Implications of Quantum Mechanics

  • The behavior of the subatomic particles (electrons, protons, neutrons, photons, and others) that make up all forms of matter can often be satisfactorily described only using quantum mechanics.

• Static Electricity, Charge, and the Conservation of Charge

  • In both instances, charged particles will experience a force when in the presence of other charged matter.
  • Electric charge is carried by subatomic particles such as electrons and protons, which can be created and destroyed.
  • For example, when particles are destroyed, equal numbers of positive and negative charges are destroyed, keeping the net amount of charge unchanged.

• Atomic Theory of Matter

  • Although physicists discovered that the so-called "indivisible atom" was actually a conglomerate of various subatomic particles, the concept of atoms is still important because they are building blocks of matter and form the basis of chemistry.
  • Knowing that a gas is composed of small atomic and molecular particles, it is natural to try to explain properties of the gas from a microscopic point of view.

• John Dalton and Atomic Theory

  • Dalton hypothesized this was due to the differences in the mass and complexity of the gases' respective particles.
  • In addition, the discovery of subatomic particles has shown that atoms can be divided into smaller parts.

• The Pauli Exclusion Principle

  • More technically, it states that the total wave function for two identical fermions is antisymmetric with respect to exchange of the particles.
  • The Pauli exclusion principle governs the behavior of all fermions (particles with half-integer spin), while bosons (particles with integer spin) are not subject to it.
  • Fermions include elementary particles such as quarks (the constituent particles of protons and neutrons), electrons and neutrinos.
  • In addition, protons and neutrons (subatomic particles composed from three quarks) and some atoms are fermions and are therefore also subject to the Pauli exclusion principle.
  • In contrast, particles with integer spin (bosons) have symmetric wave functions; unlike fermions, bosons may share the same quantum states.