Neutrons Definition and 224 Threads

Just one quick question I couldn't find an answer on the internet to, after a long search. We are taught that atoms are made from protons, neutrons and electrons only. There are many other leptons and hadrons existing, but where are they in this story?

I was checking and I couldn't find a similar thread so I am going to ask it here. I read a paper from Franz Wilczek and I do see that Protons mass comes from the masses of quarks and gluons but they account for only part of the protons mass , so where does the other part comes from , I guess...

Dear Physics Forum, I wanted to know if there is any theory of elementary particles that explains why protons, neutrons, and electrons assemble into atoms? When these particles were first made in the Universe, why do the assemble into atoms? For example, why don't electrons simply bind...

I am just curious, for nuclear power plant or nuclear weapon/detonation, how to create a beam of neutron that's energetic enough to go inside the U-235 atom and trigger the chain reactions? What was the most conventional or the oldest way to create this beam of neutrons in lab back in the...

If the free neutron decays in only 15 minutes, why are neutrons in the nucleus attached to protons stable? This has always bewildered me. Just a side question, are 'tetraneutrons' stable or even possible?

This paper is getting splashed all over the science news heres the arxiv version: http://arxiv.org/pdf/1203.1035.pdf heres the Physics world version: http://phys.org/news/2012-06-neutrons-parallel-world.html They seem to be claiming 5 sigma , any thoughts? Less prosaic explantions?

and nuclei are so small(on an atomic level!). is it that there are SO many atoms around and that thermal neutrons are still incredibly fast, that if there is a reflector surrounding(lets say we're talking about a critical mass of uranium and an uncontrolled chain reaction), that the neutron will...

So, watching the chart of isotopes (or nuclides), where I have isotopes put according to how stable they are, I have seen that the stable elements have more neutrons than protons. And I wonder why that is? Is it because neutrons are responsible for binding the nucleus with nuclear force...

What state of matter are atomic particles be in? A friend of mine suggested they might be virtual particles.

"Neutrons don't decay in nuclei because no available states" incorrect? Hello, If I understand correctly, the argument for a neutron (usually) not decaying when in a nucleus, is that the resulting proton would then have to occupy a high energy level, the lower levels already being occupied...

During certain processes, there can be free neutrons. If an accelerator beam hits into a target, it can spray neutrons into a cloud, called neutron skyshine for example. What happens to these neutrons that float around? My guess would be that they float around until they beta decay into a...

Can accelerating neutrons emit electromagnetic waves? Will neutrons absorb or reflect EM waves? If not, what would a very large collection of neutrons look like? (I am assuming there are no protons/electrons present and the neutrons are not decaying)

I am new to nuclear engg., i want to know the phenomenon of elastic scattering of neutrons. Resources available in the net suggest that in materials containing atoms of low atomic mass(hydrogen), neutrons of all energies can lose a significant fraction of their energy in a single elastic...

What if: There are only discrete protons in the atomic nucleus combined with electrons (not the orbital ones) being shared,in some random manner, leaving a net positive charge. The two particles only become discrete with the known different characteristics when the atom is "smashed" and a...

If there was some way to strip matter of it's neutrons, would that give you matter of all the same properties except for inertia? Or would it diffuse throughout space? I kind of get the notion that neutrons act as anchors to keep objects in one place. Maybe that's what a black hole does and...

Ok I am kinda happy becuase this is my first Post on this website. I love physics. I am wondering if we as humans have established the knowledge of what exactly Protons, Neutrons, and Electrons are. Down to their core, could they be energy? By energy I mean a source of power small or big. I...

Why can't I have a neutral particle come into a cloud chamber and leave a track? I was reading about cloud chambers and it says when the charged particle comes in it ionizes the vapor in the chamber. But why couldn't a neutron come in and ionize the particles in the chamber with its kinetic...

life of a single free neutron is nearly 15 min. what is the life if 2 are more neutrons adhering together? will it increase or same?

Elastic and Inelastic neutrons scattering..! How I can find the energy lost by the neutron in elastic scattering and inelastic scattering, if we assumed its isotropic scattering in the center of mass?

Elastic and Inelastic neutrons scattering..! How I can find the energy lost by the neutron in elastic scattering and inelastic scattering, if we assumed its isotropic scattering in the center of mass?

Hello everyone, Is there such a thing as range graph as a function of the energy for the neutrons in matter? I have been looking for it all over the web, but I just found the cross sections plotted when the neutron comes from different reactions. Is there a more general graph that discribes the...

How many free neutrons in the universe are there decaying at any given time?

http://physicsworld.com/cws/article/news/3525 I was reading this article about the neutron drop experiment. And it says " According to the researchers, these heights correspond to the peaks in a standing wave created when the de Broglie wave of the neutron interferes with its reflection...

The absorption or emission of W bosons changes neutrons to protons or protons to neutrons.Also,W bosons are almost 100 times as massive as the proton.The question is-How can a neutron emit a particle much more massive than itself and convert into a proton?

Quick question: photons do not interact with other photons photons do interact with electrons photons do interact with protons (I think) so do they intereact with neutrons? How could you tell, if the energy state of the neutron changed from absorbing a photon?

Hi all, I would like to know what is the relation between charge and mass (of electron/proton/neutron). How far their masses involve in force that exists between them ?

Homework Statement I am given an equation, say (239/94)Pu-->(110/53)Fe+(125/41)Nb+4neutrons I am asked to calculate the relativistic energy so I do that. Q=m(left)-m(right)c^2 I know that m(left)=m(Pu) I know that m(right)=m(110Fe)+m(125Nb)+4m(neutron) (i put the answer into MeV for...

Question-A certain crystal has a set of planes spaced 0.376 nm apart. A beam of neutrons strikes the crystal at normal incidence and the first maximum of the diffraction pattern occurs at a scattering angle (i.e angle between incoming neutrons and reflected beam) of 41.4 degrees. What is the de...

When two free neutrons collide at high speed do they ricochet off one another like billiard balls? If so, what is the force that they exert on one another in order to change their velocities? It clearly isn't gravitational or electromagnetic. The only other fundamental forces are the strong...

In the early universe the quarks where moving freely. So I am wondering how did the quarks enter the protons and neutrons shell/wall after the temperature where ok for it to happen? Or, how did the protons and neutrons encapsulate the quarks?

The quarks in neutrons have opposide charges and therefore they should attract, but why don't they just fall into each other. Is it the Heisenberg principle or degeneracy pressure?

What is the difference between the particle formed by the combining of a proton and a neutron and a neutron?

Homework Statement A pion is a spin-0 particle with a negative unit charge. A neutron is a spin-1/2 particle with no charge. A proton is a spin-1/2 particle with positive unit charge. One can construct an unstable version of the hydrogen atom where the nucleus contains both a proton and a...

Homework Statement In a double slit experiment, a beam of neutrons with speed 0.6m/s is diffracted by two apertures which are 0.05μm apart. a. What is the neutron wavelength? b. Where does the first minimum appear? Homework Equations \lambda = \frac{h}{p} dsin\theta =(m+\frac{1}{2})\lambda...

(1) Is there any equation to determine how many neutrons there should be to keep an atom stable? I don't mean mass - number of protons. I mean the equation that can determine an interval of neutrons based on atomic number only and the forces. (2)Why can't there be an hydrogen atom with 6...

Greetings, What force keeps neutrons apart? And quarks? What keeps them from collapsing together? Thanks

Why atomic mass doesn't match the number of protons and neutrons in it? for example mercury mass is 200 gmol but it has only 80 protons and 80 neutrons. From where does 40 gmol come from?

Homework Statement Fission reaction: 10n + 23592U --> 14156 + 9236 Kr + 3(10n) Why in the world is there a neutron on the left side of this rxn? Why not just reduce the number of neutrons on the right side to two?

My teacher explained that when a large nucleus has too few neutrons, the binding energy is not enough to hold the nucleus together. But by adding neutrons the binding energy increases without increasing the repulsion between nucleons, and thus the nucleus can stay together. But atoms that have...

Can we or have we made an atom of neutrons?

If we bombard a gas or plasma of Deuterium with Neutrons will they "stick" and from Tritium?

My question: do there exist particles similar to atomic nuclei, but made only of neutrons? If not, then why? I suspect that this would be beta-unstable, but it should live for some time and get observed somehow.

Homework Statement on a test, i wrote neutrons for something that flows (laminar) On some occasions do they flow smoothly? Homework Equations The Attempt at a Solution

I have been given the impression that the weak force is what holds the neutron together (preventing it from decaying to an electron and proton) and that the neutron eventually decayed, despite this weak force, by 'tunneling out' Is that right or am I way off?

i understand that free neutrons are unstable and decay within about 10 mins, presumably because of the weak nuclear force would anti neutrons theorectically behave in the same way, or would anitmatter-matter chirality impact at all?

How do we know protons, neutrons and electrons exist? And what exactly is a positive or negative charge?... meaning what is it that makes it positive or negative.

Can there be any particle other than a proton or a neutron that can remain stably in the nucleus of an atom at ordinary temperatures and pressures? I'm aware of hypernuclei (nuclei containing hyperons) but none of those are stable. I understand that they all decay weakly. Is there any...

Why is it that neutrons don't stick together? As far as I know the nuclear force is also acting between 2 neutrons and not just between neutrons and protons. So why are there no ultra dense neutron objects consisting of a large number of neutrons, except of course for neutron stars where...

Hello; My physics teacher asked me to name the combinations of quarks that could make up a proton and a neutron; uud = proton udd = neutron But is that all? Does it have to be 2 up quarks and 1 down quark to make the proton? Why not 2 charm quarks and 1 strange quark, for example? Or 2...

before i start i wanted to make it clear that this is NOT homework. its just a quick question which puzzled me and my friend In the shell model of the nucleus. i found a statement that said that since both neutrons and protons are fermions, there are restricted to 2 of each at each energy...