Electron Radius (Classical) to Femtometer Converter
Unit Converter
Instant · Precise · Universal
32 units available
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How to Convert Electron Radius (Classical) to Femtometer
To convert to meters: multiply by 2.8179403262 × 10⁻¹⁵.
re = e²/(4πε₀mec²) ≈ 2.8179 × 10⁻¹⁵ m, where e is electron charge and me is electron mass.
For example, 1 Electron Radius (Classical) (re) = 2.817940326 Femtometer (fm).
Electron Radius (Classical) to Femtometer — Common Values
| Electron Radius (Classical) (re) | Femtometer (fm) |
|---|---|
| 0.1 | 0.2817940326 |
| 0.5 | 1.408970163 |
| 1 | 2.817940326 |
| 2 | 5.635880652 |
| 5 | 14.08970163 |
| 10 | 28.17940326 |
| 25 | 70.44850815 |
| 50 | 140.8970163 |
| 100 | 281.7940326 |
| 500 | 1408.970163 |
| 1000 | 2817.940326 |
About Electron Radius (Classical) (re)
Definition
The classical electron radius is a theoretical length scale derived from the electron's charge and mass, approximately 2.818 × 10⁻¹⁵ meters.
Mathematical Relationship
re = e²/(4πε₀mec²) ≈ 2.8179 × 10⁻¹⁵ m, where e is electron charge and me is electron mass.
Conversion Formula
To convert to meters: multiply by 2.8179403262 × 10⁻¹⁵.
Practical Applications
Used in calculating X-ray and gamma-ray scattering probabilities off electrons (Thomson and Compton scattering).
Interesting Facts
Despite its name, the electron is a point particle in quantum theory — the 'classical radius' is a theoretical construct, not the electron's actual size.
Common Mistakes
Assuming this is the actual physical size of the electron — quantum mechanics shows the electron has no measurable size.
Educational Tips
Think of it as the scale at which classical electromagnetic self-energy equals the electron's mass-energy.
About Femtometer (fm)
Definition
The femtometer is a unit of length equal to 10⁻¹⁵ meters, commonly used to measure the size of atomic nuclei.
Mathematical Relationship
1 fm = 10⁻¹⁵ m = 1,000 am = 10⁻⁶ nm. One meter equals 10¹⁵ femtometers.
Conversion Formula
To convert fm to meters: multiply by 10⁻¹⁵. To convert meters to fm: multiply by 10¹⁵.
Practical Applications
Describing the size of protons (~0.87 fm radius) and nuclear diameters (1–15 fm depending on the element).
Interesting Facts
A proton's charge radius is approximately 0.87 fm. The diameter of a uranium-238 nucleus is about 15 fm.
Common Mistakes
Confusing femtometers with nanometers — a femtometer is one million times smaller than a nanometer.
Educational Tips
Remember: atoms are ~0.1 nm, but nuclei are ~1–10 fm — nuclei are about 100,000 times smaller than the whole atom.