Register to reply

How can a proton form a neutron?

by Matriculator
Tags: form, neutron, proton
Share this thread:
Apr12-14, 01:29 PM
P: 54
This is related to a homework problem but I want to understand it as well. How can a proton break up into a positron and neutron when a neutron clearly has a greater mass than a proton?
Phys.Org News Partner Physics news on
'Squid skin' metamaterials project yields vivid color display
Team finds elusive quantum transformations near absolute zero
Scientists control surface tension to manipulate liquid metals (w/ Video)
Apr12-14, 02:39 PM
Astronuc's Avatar
P: 21,910
Positron emission occurs in proton-rich nuclei, although in many, electron capture is also possible.

An isolated proton would not decay by positron emission, but an isolated neutron will spontaneously decay.
Apr12-14, 08:17 PM
jtbell's Avatar
P: 11,862
Consider 22Na which undergoes β+ decay to 22Ne.

22Na has 11 protons and 11 neutrons, whereas 22Ne has 10 protons and 12 neutrons. Nevertheless, the mass of a 22Na nucleus is greater than the sum of the masses of a 22Ne nucleus and an electron, because of the different binding energies of 22Na and 22Ne.

Apr16-14, 11:14 AM
P: 9
How can a proton form a neutron?

An isolated proton can not decay since is the lightest particle with baryon number equals to one.
A proton in the presence of other stuff like other protons or neutrons so for instance a proton that is making up the nuclei of some atom may ''borrow" energy from this environment and then it can decay (always conserving baryon number and charge and so on) so one (very) possible outcome will be positron and neutron

Register to reply

Related Discussions
An electron and a proton can not form a neutron because they are short High Energy, Nuclear, Particle Physics 21
Neutron proton hit High Energy, Nuclear, Particle Physics 2
Neutron to Proton High Energy, Nuclear, Particle Physics 53
Is neutron-neutron fusion easier to facilitate than proton-proton General Physics 5
Proton and neutron High Energy, Nuclear, Particle Physics 11