`` NEWTON Beta Decay, Protons, Neutrons
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Name: Bridget
Status: student
Grade: 9-12
Location: IL
Country: USA
Date: Winter 2013-14

In chemistry class, I am learning about radioactive decay of nuclei. In beta decay, a neutron splits into a proton and an electron. In positron emission, a proton becomes a neutron and a positron. My question is this: how can a neutron be composed of a proton and an electron when a proton is composed of a neutron and a positron? For example, if a neutron is a proton and an electron and if a proton is a neutron and a positron, then a neutron would technically be a neutron, a positron, and an electron. How does this work?

Bridget, A neutron is not composed of a proton and an electron. Also, a proton is not composed of a neutron and a positron. Particles can change into other particles through an interaction often called the ?weak force?. This is the interaction that controls most of radioactivity. In beta decay, a neutron changes into a set of three particles: proton, electron, anti-neutrino. In positron emission, a proton changes into three particles: neutron, positron (i.e. anti-electron), neutrino. The neutrinos are almost massless particles that have no charge and do very little. They are very difficult to detect. Still, reality requires them to keep all the particle properties of the universe balanced.

Energy, rather than particles, is the basis of the structure of the universe. Atoms are made of a combination of particles and energy. Particles are made of energy. As for what energy actually is, that has never been discovered. Scientists know how to use energy and how to measure it, but we have never figured out just what it is. I suspect languages of the world do not have the words for it.

Dr. Ken Mellendorf Physics Instructor Illinois Central College

You are not asking a simple question – perceptive but not trivial. The “explanation” exceeds the capacity of a site like NEWTON. The web site referenced here: http://en.wikipedia.org/wiki/Beta_decay will “explain” the processes, but that “explanation” is not trivial. It will take some “digging” on your part to unravel the complicated processes. But that is how Mother Nature is operating in this process.

Vince Calder

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