# Purpose of Neutrons and other q's

1. Dec 15, 2004

### Slacker

Hello. I have a few questions to ask you guys. First, what is the purpose of neutrons in an atom? What would happen if all the neutrons in the atom were spontaneously stripped away? Also, what would happen if all the electrons in an atom were spontaneously stripped away?

2. Dec 15, 2004

### Dual Op Amp

Many scientist believe that there are even smaller particles called quarks, these quarks make up an atom. They also think that there are gluons, small particles that "glue" these quarks together. The gluon "glues" the nuetron together with a force, known as the strong force. They think that in a nuetron, there is some residual strong force that "glues" the protons together. See, like charges repell, so the positive forces of the proton should repell each other, but the strong force is strong enough to overcome that electrostatic repullsion. I, simply, learned this from research, I have no idea how they theorized this or what type of research was done to devolope this theory.

Now, the scientists think that the nuetron and proton are composed of three quarks, there are up-quarks and down-quarks.
Up-quark has a charge of +2/3.
down-quark has a charge of -1/3.
Neutron has an up-quark and a down-quark.
2/3 - 1/3 - 1/3 = 0
Proton has a down-quark and two up-quarks.
2/3 + 2/3 - 1/3 = 1
As for stripping off the electrons, that would just ionize the atom.

Last edited: Dec 15, 2004
3. Dec 15, 2004

### Tjl

Just a little extra note, finding ionized atoms is not very common. Because of octet rule and how it affects the atom. So it is rare to find them in nature.

4. Dec 15, 2004

### Staff: Mentor

Neutrons and protons are nucleons, and as Dual Op Amp pointed out, it is believed they are composed of 3 quarks.

The neutron allows more than one proton to combine to form a nucleus. The nuclear force overcomes the coulomb repulsion.

If the neutrons were expelled from a nucleus, the protons would disperse. It is possible to 'knock-out' a proton or neutron, and even an alpha particle, but it is impossible to knock out a large number of individual neutrons or protons.

Atoms are ionized in plasmas, but negative and positive charges are never far away from the other. The electrons always try to recombine and settle into their 'ground state' in the electron orbitals around the nucleus.

It is much easier to ionize simple atoms like H or He, but becomes increasingly difficult to completely ionize heavier nuclei.

One look further into these matters by looking for keywords: spallation (e.g. http://www.sns.gov/, http://www.sns.gov/aboutsns/what-why.htm) and heavy ion accelerators (e.g. http://ref.web.cern.ch/ref/CERN/HR/AT2002/A5/)

5. Dec 16, 2004

### Pieter Kuiper

With too many protons in a nucleus, it will decays by "proton drip", positron emission, or alpha decay.

Or by electron capture.

Last edited: Dec 16, 2004
6. Dec 16, 2004

### misogynisticfeminist

Don't 2 protons feel the strong force when placed very close each other as well? And is it possible for 2 protons to stick together as a nuclei w/o neutrons in it?

7. Dec 16, 2004

### Dual Op Amp

Don't know, most of this is just theory. Meaning, the scientists don't know. But, if there was residual strong force, could that be the ellusive...Gravity?
If so, the well known lepton - electron - would be the solution to anti-gravity.

8. Dec 23, 2004

### Staff: Mentor

I don't believe gravity could overcome the repulsive coulombic forces of two protons. On the other hand, clearly the strong nuclear force can overcome the coulomb repulsion, that is, in the presence of a neutron.

As far as I know, He-2 does not exist, and cannot be made. We know of He3 and He4, which are both stable. He-5 can be produced, and may exist in stars.

See http://wwwndc.tokai.jaeri.go.jp/CN03/
for a list of nuclides.

9. Dec 23, 2004

### dextercioby

For about 340 years we have a formula that tells us that ANY 2 MASSIVE BODIES attract with a force who's given by:
$$F_{Newton}=G\frac{m_{1}m_{2}}{r_{12}^{2}}$$
GR does not make significant modifications for masses of the order of elementary particles like quarks,neutrons,protons...
Strong interaction is purely QUANTUM,and all of us know that,at quantum level,the concept of 'force' does not not exist.However,physicists could tell very sure that FOR ELEMENTARY PARTICLES CALLED HADRONS (particles which "feel" the strong interaction) GRAVITY IS MUCH,AS IN 'VERY MUCH',WEAKER THAN THE STRONG INTERACTION.At quantum level,we would have to compare the coupling constants for gravity (Cavendish constant) anf for QCD.Residual strong interaction is strong enough to overcome the electromagnetic interaction (note,i didn't use 'Coulomb potential') between protons.
And for the sake of history:The hypothesis that all nuclides are made up of protons and neutrons was made symultaneously by Heisenberg and Ivanenko in 1932 (the same with the discovery of neutron by Chadwick).Quark-made-up nuclei hypothesis by Murray Gell-Mann (1964) turned Heisenberg-Ivanenko's hypothesis into oblivian.But only for the ignorant...

Daniel.

PS.The goal of theoretical physicsts is to show that all particles experience/feel the strong interaction.That is to say,that all 4 fundamental interactions are unified.

Last edited: Dec 23, 2004
10. Dec 23, 2004

### marlon

What the f*** :surprised ???

Leptons (eg the electron) does NOT feel the strong force and they never will...

Unification will have to start out from a point where the coupling constants of the four interactions are equal in magnitude at one specific energy or distance-scale (you know : small energies are equivalent to large distances via Heisenberg-uncertainty). This is at about 10^(-25) metres...

Also, keep in mind that unification is NOT the same as writing down a theory of everything. At some first degree it is NOT the intention to write down ONE model that explains and describes "all" phenomena, rather we try to fit gravity into the realm of QFT by :

1) holding on to General Relativity and rewriting QFT = Loop Quantum Gravity
or by
2) holding on to QFT and "re-invent" General Relativity = String Theory

But my point is that no interaction will be completely dominant with repect to the other ones, so not all particles need to feel the strong force. However, we try to get rid of the fundamental differences of QFT and General Relativity...I am referring to uncertainty and curvature of space-time...

regards
marlon