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Name:  David P. Bligh
Status: other
Age: 40s
Location: N/A
Country: N/A
Date: 2000-2001

What is the radius of a proton?


The radius of a proton depends on how you mean radius. It turns out that a proton is not actually a ball. Latest experiments show that a proton is made of three smaller particles called quarks. Quarks have a size too small to measure. They may have no size at all. These three quarks spin around each other very quickly. In reality, a proton does not have a radius. As for radius of orbits, that involves an area of quantum mechanics that is still being explored. We do not yet know enough about the force between quarks to determine a value for orbit sizes within a proton, or a neutron.

Dr. Ken Mellendorf
Illinois Central College

Atomic nuclei are roughly spherical, and have a radius given by: R=Ro*A^1/3 where Ro = 1.2x10^-15 meters and A is the atomic number. These are experimentally determined by electron scattering.

Vince Calder

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