- #1
Invinoveritas
- 9
- 0
Do they just destroy each other?
Bob S said:The only case when atomic electrons interact with the nucleus is in a type of beta decay called K capture
Bob S said:when a proton in the nucleus does not have enough energy to decay to a neutron and a positron, but does have enough energy to decay to a neutronif it can capture an electron from the K shell.
Bob S said:Beryllium-7 is an example.
Vanadium 50 said:Um...not exactly. An electron interacts electromagnetically with a nucleus, and there is a small correction to the atomic energy levels due to the electron spending a fraction of its time inside the nucleus.
feynmann said:Is there another force that counteracts the force of charge trying to pull them together?
If not, then why the electron won't fall into the proton?
Phrak said:Gravitating a little closer to the OP question...
A free neutron decays into a proton, an electron and an anti nuetrino in about 10 minutes. A free neutron is free--it's not inside a nucleus. The resultant particles go buzzing off in all directions, each with some kinetic energy. So the opposite charges of the electron and positron are not enough to keep them bound together. It takes some energy to get them to stick together into one particle.
(Or maybe the question was 'why don't an electron and proton anihilate each other? But I think Invinoveritas was scared away by the 10 dollar words.)
Invinoveritas said:Ideas on what would happen?
What would happen to the energy that was previously keeping them apart?
feynmann said:Is there another force that counteracts the force of charge trying to pull them together?
If not, then why the electron won't fall into the proton?
malawi_glenn said:This is what lead one to consider quantum mechanics: "why does not the electron fall into the proton?"
The easiest answer is that the form of the solutions to the Schrödinger Equation prevents this, only in the ground state, there is a non zero probability for the electron to be located at the origin (where the nucleus resigns) - we have to forget about that particles are tiny balls with classical forces acting between them.
Second is that from QM, we get something called the Heisenberg uncertainty relation, the electron can not be located at a specific position with 100% certainty, only with less. Thus one can only talk about a probability per unit time that an electron undergoes inverse beta decay with a proton in the nucleus.
So there is no additional force, we just have to forget about our classical, intuitive picture of particles as being tiny balls with classical forces acting on them.
Vanadium 50 said:Not exactly. Na-22, for example can and does emit positrons but also has a 10% branching ratio for electron capture..
malawi_glenn said:well yes, since I just said that there is no additional 'force',
there are two forces involved, whereas gravity is 10^-19 times weaker than EM-force. The reason for the electron not spiralling down to the nucleus due to attractive EM-force is just the imposing of certain physical boundary conditions to the Schrödinger equation, which isthe "equation of motion" at quantum level.
malawi_glenn said:well yes, since I just said that there is no additional 'force',
there are two forces involved, whereas gravity is 10^-19 times weaker than EM-force. The reason for the electron not spiralling down to the nucleus due to attractive EM-force is just the imposing of certain physical boundary conditions to the Schrödinger equation, which isthe "equation of motion" at quantum level.
alxm said:Do you have a ref. for that? I've never heard of such a correction being done.
Obviously there's an effect, since the nucleus is not the infinitesimal point charge it's usually modeled as, but it's still dang small. I can't imagine the effect being larger than something on the parts-per-million scale of the electronic energy. (and certainly smaller than the thermal energy at any reasonable temperature, making it physically insignificant)
Your estimation is in the right ballpark, but you are wrong that it can not be measured.alxm said:Do you have a ref. for that? I've never heard of such a correction being done.
Obviously there's an effect, since the nucleus is not the infinitesimal point charge it's usually modeled as, but it's still dang small. I can't imagine the effect being larger than something on the parts-per-million scale of the electronic energy. (and certainly smaller than the thermal energy at any reasonable temperature, making it physically insignificant)
Proton Structure Corrections to Hydrogen Hyperfine SplittingAs a result, the total calculated hyperfine splitting now has a standard deviation slightly under 1 part-per-million, and is about 1 standard deviation away from the measured value.
Invinoveritas said:Thank you.
I was just thinking about how great it would be if you could force an atom to collapse itself and release energy in that process.
malawi_glenn said:This is what lead one to consider quantum mechanics: "why does not the electron fall into the proton?"
The easiest answer is that the form of the solutions to the Schrödinger Equation prevents this, only in the ground state, there is a non zero probability for the electron to be located at the origin (where the nucleus resigns) - we have to forget about that particles are tiny balls with classical forces acting between them.
Second is that from QM, we get something called the Heisenberg uncertainty relation, the electron can not be located at a specific position with 100% certainty, only with less. Thus one can only talk about a probability per unit time that an electron undergoes inverse beta decay with a proton in the nucleus.
So there is no additional force, we just have to forget about our classical, intuitive picture of particles as being tiny balls with classical forces acting on them.
feynmann said:But how do we know Schrödinger Equation is correct. I guess the answer is that experiments confirm its predictions. So the reason to the OP, "why electrons won't crash to their proton" is that experiment show electrons won't crash to their proton
malawi_glenn said:You would then need energy to do that, and since atoms are weakly bound, you would not gain that much. The energies in atoms are of the order 10eV, whereas in nuclei the energies are of the order 1MeV, i.e 100 000 times bigger.
humanino said:Your estimation is in the right ballpark, but you are wrong that it can not be measured.
An electron-proton collision is a type of interaction between an electron and a proton, the two fundamental particles that make up an atom. This collision occurs when the electron and proton come into close proximity and are subjected to strong electromagnetic forces.
When an electron crashes into its proton, the two particles undergo a process known as scattering. This means that the electron and proton will deflect off of each other, changing the direction and energy of both particles.
During a collision, the negatively charged electron and positively charged proton will experience a strong attraction due to their opposite charges. This attraction causes the electron to move towards the proton, resulting in a close interaction between the two particles.
The effects of an electron-proton collision can vary depending on the energy and angle of the collision. In general, this type of collision can result in the creation of new particles, such as positrons or photons, and can also produce electromagnetic radiation.
Scientists study electron-proton collisions to better understand the fundamental properties of matter and the forces that govern the behavior of particles at the subatomic level. These collisions can also provide insights into the structure of atoms and the nature of the universe.