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Facts About Particles for Kids


In the physical sciences, a particle is a small localized object to which can be ascribed several physical properties such as volume or mass. Whether objects can be considered particles depends on the scale of the context; if an object’s own size is small or negligible, or if geometrical properties and structure are irrelevant, then it can be considered a particle.

  • For example, grains of sand on a beach can be considered particles because the size of one grain of sand (~1 mm) is negligible compared to the beach, and the features of individual grains of sand are usually irrelevant to the problem at hand.
  • The concept of particles is particularly useful when modeling nature, as the full treatment of many phenomena is complex.
  • Francis Sears and Mark Zemansky, in University Physics, give the example of calculating the landing location and velocity of a baseball thrown in the air.
  • When studied in the context of an extremely small scale, quantum mechanics starts to kick in, and give rise to several phenomena such as the particle in a box problem and wave–particle duality, or theoretical considerations, such a whether particles can be considered distinct or identical.
  • The term macroscopic particle, usually refers to particles much larger than atoms and molecules.
  • Another type, microscopic particles usually refers to particles of sizes ranging from atoms to molecules, such as carbon dioxide, nanoparticles, and colloidal particles.
  • By contrast, elementary particles (also called fundamental particles) refer to particles that are not made of other particles.
  • However it is possible that some of these might turn up to be composite particles after all, and merely appear to be elementary for the moment.
  • In computational physics, N-body simulations (also called N-particle simulations) are simulations of dynamical systems of particles under the influence of certain conditions, such as being subject to gravity.
  • These simulations are very common in cosmology and computational fluid dynamics.
  • A colloid is a substance microscopically dispersed evenly throughout another substance.
  • The dispersed-phase particles have a diameter of between approximately 5 and 200 nanometers.