Convert picometer to Electron radius (classical) Online | Free Length Converter

Picometer

A picometer (pm) is an extremely small unit of length in the metric system, equal to one-trillionth of a meter (1 pm = 10⁻¹² meters). Picometers are used to measure things on the atomic and subatomic scale, such as the size of atoms or the distance between particles in a molecule. For example, a hydrogen atom is about 50 picometers in radius. This unit is mainly used in physics, chemistry, and nanotechnology. Because it's so small, you won’t see picometers used in everyday life — they are only relevant in scientific research where ultra-precise measurements are required.

Classical Electron Radius

The classical electron radius is a theoretical length scale associated with the electron, derived from classical electromagnetism. It represents the size of a hypothetical sphere where the electron’s electrostatic energy equals its rest mass energy.

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  Its value is approximately 2.818 × 10⁻¹⁵ meters (about 2.8 femtometers).

  
  
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  Calculated using fundamental constants: the electron charge, mass, and the speed of light.

  
  
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  It is not the actual physical size of the electron (which is considered point-like in quantum mechanics), but a useful scale in classical physics.

  
  
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  Used in scattering theory and classical electron models.

  
  

Key facts:

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  Classical electron radius ≈ 2.818 × 10⁻¹⁵ m

  
  
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  Represents an electromagnetic length scale, not a physical size

  
  
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  Important in classical models of electron behavior

  
  

This radius helps bridge classical and quantum views of particle physics.