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Posted

we`re taught there are 3 types of particles to make up an atom, the Proton Neutron and Electron.

 

but since Neutrons are made of Protons and Electrons as evidenced in the making of a Neutron star and in their Breaking in a Beta decay.

 

aren`t there really only 2 types of particle and not 3?

 

and since Hydrogen is made of 1 of each of these, is that why Hydrogen is probably the most Cosmologically important element?

Posted

no, there are really 7 that make up normal matter, 3 types of quark and electrons...

 

Of course there are also neutrinos (3 types I think), tauons, muons, anti-particles for all of the others, I can't remember how many fundamental particles the standard model predicts but it is a surprisingly large number...

 

There's a list of fermions here:

 

http://en.wikipedia.org/wiki/Standard_Model#List_of_standard_model_fermions

 

But I've not read most of the other stuff on the page...

Posted

that`s ok, but I`m not interested in going That far down the scale, I`m looking at Cosmology from a Chemists perspective.

 

in terms of Elements and what the difference is between each element (which is Surprising Little in reality).

 

Hydrogen seems to be the Key, it`s the perfect balance of a + and - charge and under the right conditions Anything can be made from it.

Posted

But saying neutrons are made of protons is incorrect...

 

A Neutron is two down quarks and an up quark. Whereas a proton is two ups and a down..

Posted

so a neutron does Not consist of a Proton and an Electron squeezed together?

 

and yet that`s exactly what happens when a Neutron star is formed, the electrostatic repulsion of the electrons is no longer sufficient to overcome gravity, and eventually gravity wins and squishes the protons and electrons together to make Neutrons!

Posted
so a neutron does Not consist of a Proton and an Electron squeezed together?

 

No.

 

and yet that`s exactly what happens when a Neutron star is formed, the electrostatic repulsion of the electrons is no longer sufficient to overcome gravity, and eventually gravity wins and squishes the protons and electrons together to make Neutrons!

 

That's not something I recall from when we studied neutron stars, but it was a few years ago... The neutron ---> proton, an electron and an electron antineutrino decay is more complicated than them just being squashed together...

 

http://hyperphysics.phy-astr.gsu.edu/hbase/particles/proton.html#c4

Posted

and yet that`s exactly what happens when a Neutron star is formed, the electrostatic repulsion of the electrons is no longer sufficient to overcome gravity, and eventually gravity wins and squishes the protons and electrons together to make Neutrons!

 

In principle, there is an interaction which can turn an electron and an up quark into a neutrino and a down quark. This interaction could in principle turn an electron and proton into a neutron and neutrino, and this is what happens in neutron stars.

 

But there are two difficulties with the interaction. Firstly, it is a weak interaction, so very short range. Secondly the neutrino and down quark combined are heavier than the up quark and electron, so you need to put quite a bit of energy in to make up the difference (E=mc2).

 

But if you push the electron really close to the proton (like in the formation of a neutron star), eventually they are close enough together to overcome the range problem and the energy of the electromagnetic interaction (or in other words, the energy required to push them so close) is enough to make up the mass difference, and whoosh, they convert to neutron and neutrino (and since both of these are neutral the electromagnetic repulsion, and its associated energy, is no longer there).

 

Incidentally, it is a good job that there are these two difficulties with the interaction, otherwise you would have rapid proton decay, which could be rather catastrophic to the entire universe.

Posted

Just because when something falls apart, it turns into two things, doesn't mean that it was originally made of those two things. For instance, in the case of gamma-radiation, the gamma photon wasn't there all along. The idea that it should have been comes from intuition gained from the medium scale which doesn't apply at the atomic scale, as is my understanding.

Posted

Photons are elementary particles, they are often thought of as more wave-esque, but everything in the world expresses wave like properties and it doesn't stop them from being particles.

Posted

well You can use the term "Gamma Particles" all you like, I`d rather Not.

 

I`ll stick to Gamma rays or X-Rays if it`s all the same to you.

Posted

The terminology is far from the point. The fact is that photons (and everything else) are both waves and particles.

 

There is no way that a photon is any more wave like than an electron or that an electron is more particle like than a photon. There is no getting around the fact that photons just are fundamental particles.

Posted

an electron has Mass.

yes there IS a difference, btw, stop Hijacking the thread and get back to topic will you, it`s not the 1`st thread you`v done this in directly after I`v posted.

Posted

but since Neutrons are made of Protons and Electrons as evidenced in the making of a Neutron star and in their Breaking in a Beta decay.

Neutrons aren't made from protons and electrons. A neutron is made of 2 down-quarks and 1 up-quark, while protons are made of 2 up-quarks and 1 down-quark. And an electron acts like a light quark itself
aren`t there really only 2 types of particle and not 3?
There are more than 2 or 3. Think of quarks, gamma rays, electron-neutrinos, tau-neutrinos, muon-neutrinos, photons, gravitons, gluons etc.

There was a period of time when particles where being discovered very fast, and there was a joke that any brilliant physicist who didn't discover a particle at that time, would get a Nobel!

 

and since Hydrogen is made of 1 of each of these, is that why Hydrogen is probably the most Cosmologically important element?
That is just an assumption!
Posted
that`s ok, but I`m not interested in going That far down the scale, I`m looking at Cosmology from a Chemists perspective.

I would highly recommend you read "The Magic Furnace" by Marcus Chown.

 

http://www.amazon.co.uk/Magic-Furnace-Marcus-Chown/dp/0099578018

 

 

Every breath you take contains atoms forged in the blistering furnaces deep inside stars. Every flower you pick contains atoms blasted into space by stellar explosions that blazed brighter than a billion suns." Thus begins The Magic Furnace , an eloquent, extraordinary account of how scientists unraveled the mystery of atoms, and helped to explain the dawn of life itself.

 

The historic search for atoms and their stellar origins is truly one of the greatest detective stories of science. In effect, it offers two epics intertwined: the birth of atoms in the Big Bang and the evolution of stars and how they work. Neither could be told without the other, for the stars contain the key to unlocking the secret of atoms, and the atoms the solution to the secret of the stars. Marcus Chown leads readers through the major theories and experiments that propelled the search for atomic understanding, with engaging characterizations of the major atomic thinkers--from Democritus in ancient Greece to Binning and Rohrer in twentieth-century New York. He clarifies the science, explaining with enthusiasm the sequence of breakthroughs that proved the existence of atoms as the "alphabet of nature" and the discovery of subatomic particles and atomic energy potential. From there, he engagingly chronicles the leaps of insight that eventually revealed the elements, the universe, our world, and ourselves to be a product of two ultimate furnaces: the explosion of the Big Bang and the interior of stars such as supernovae and red giants.

 

Chown successfully makes these massive concepts accessible for students, professionals, and science enthusiasts. His story sheds light on all of us, for in essence, we are all stardust.

Posted

iNow, yeah man, I just love this stuff, reading it or watching the documentaries about it :)

 

it`s Fantastic!

 

 

(have a Virtual Rep Point).

Posted
well You can use the term "Gamma Particles" all you like, I`d rather Not.

 

I`ll stick to Gamma rays or X-Rays if it`s all the same to you.

What about Cathode rays? Do you like that term? We use Cathode rays a lot. In CRT Monitors (and TVs) they use Cathode Rays (Hence the name Cathode Ray Tube).

But what are cathode rays? They are...

 

...electrons

 

:doh:

 

Yes, what you have specifically labeled as a "Particle" is also labled as a "Ray". :eek:

 

So the "label" is realy just a language convention and not really describing what they are. So Gamma Rays could also be called Gamma Particles (High energy Photons).

 

In fact, under QM all matter and force carrying particles (like phonots) becave both as Waves (rays) and Particles.

 

The two slit experiment deomstrates this. Particles will not interfere with each other, but waves will (it is a fundamental property of waves). Both Light and Electrons (also protons, neutrons and even molecules) also show this interference pattern of waves. But the detector at the end only records a single point of impact (rather than a wave front). So this experiment demonstrate that they are all waves (interference) and demonstrates that they are particles (single point impacts).

 

Calling them a "Particle" or a "Wave" (Ray) is a linguistic convention when dealing with that aspect of the objects behaviour.

 

They are all neither particle or wave. They are something that we, as of yet, don't really have a word for (I propose "Wavicle" :D ).

 

aren`t there really only 2 types of particle and not 3?

Well it might be that all particles are just variations on a single fundimental particle, but we don't really know yet (or even if that is possible).

 

Again, this is down to convention. We need a way to seperate the differnet behaviours of particles. Neutrons have a different mass and electric charge to a proton or electron, so we call it a different particle.

 

Actually, a Proton and Neutron are made up of multiple partices (as has been stated eariler) and the ratios of them are different (2 Up and 1 Down as compared to 1 Up and 2 Down).

 

Lets look at it another way:

An atom is made up of multiple "particles" (Protons, Electrons and Neutrons). If we have a different configuration of particles (more or less of one type of particle in the atom), then we call it a differnet type of atom. We can have Hydrogen, Oxygen, Radium, etc. They behave differently and have different properties (mass, valency, etc).

 

You would not call a Hydrogen atom the same as a Carbon atom, even though it is made up of exactly the same types of particles, just in different ratios and amounts.

 

This is the same for a neutron and proton.

 

Think about it.

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