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Name: Zackie R.
Status: student
Age: 13
Location: N/A
Country: N/A
Date: 2001-2002

When a proton or a neutron are not in a nucleus they die very quickly, so what happens to that dead particle? According to the laws of physics they just can't disappear.

Zackie, The particles do not die. It is possible for particles to "decay" into other particles. One example is a neutron decaying into a set of three particles: a proton, an electron, a neutrino. It is possible for particles to join with other atoms. It is also possible for lone proton to join with an electron, thus becoming a hydrogen atom. A free proton or neutron does not disappear. It finds a way to become part of an atom or to change into different particles.

Dr. Ken Mellendorf
Illinois Central College

"Free" neutrons have a half life of ~12 min and decay by emission of a beta particle (electron), presumably yielding a proton. The energies can be found in any "Table of Neuclides" in any handbook of physics and / or chemistry. All the conservation laws are obeyed (energy/momentum/etc.), so there are no "dead" particles remaining. The proton, and the deuteron both are stable, at least on any time scale less than "cosmic".

The mass ~3 isotope tritium has a half life of about 12 years.

None of the particles disappear.

Vince Calder

Protons outside of nuclei have not been observed to do anything. They just stay on being protons. A neutron by itself can "decay" into a neutron, a positron, and an antineutrino. Nothing disappears, it just isn't a neutron any more.

Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois

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