What makes particles stick?
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OCUK physics community seems to be in full swing tonight,
While we are at it, I'm trying to get my head around the creation of space itself. Theres no mechanism as far as I'm aware. Universe isn't expanding into anything either. So I'm thinking the presence of energy-matter creates space-time?
hmm... its getting late.
sid
While we are at it, I'm trying to get my head around the creation of space itself. Theres no mechanism as far as I'm aware. Universe isn't expanding into anything either. So I'm thinking the presence of energy-matter creates space-time?
hmm... its getting late.
sid
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Indeed. And don't forget the Cassimir effect - that's what makes mayonnaise fluffy!Don't forget Van der Waals and other similar forces at short range.
It's been a while since I did physics. I believe the standard model dictates that the strong, weak and electromagnetic forces come about due to information exchange in the form of "virtual" photons.
But yes, in general most things around you on the atomic level will be held together by ionic (metals) or covalent (non-metals in general!) bonds. Hydrogen bonding occurs due the fact that covalent compounds aren't perfectly symmetrical.
Also, fission is "dirty" because it produces radioactive waste which cannot be easily disposed of. Fission generally turns 2 Hydrogen atoms into 1 Helium atom. And besides from making you talk funny, Helium is harmless (with the exception of being suffocated on it, but you get the idea).
Fusion is what makes the sun burn.
Nuclear forces are a ridiculously high magnitude. It perhaps could happen if you were on the edge of the a black hole, so that the force of mavity on one particle overcame the nuclear forces.
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*Long, boring post alert*
As already stated, there are basic forces in the universe that give rise to electrostatics and mavity etc, this is fundamentally physics. The study of chemistry is much more about (though not exclusively) how these varying collections of sub-atomic particles we call elements interact with each other.
Most of the ideas learnt about structure and bonding, even up to A-level are vastly simplified, and give a rough idea, but often fall down when investigated more thoroughly.
So why do atoms 'stick'? Well once you get down to it, it's all about energy. Atoms adopt structures that minimise their energy as best as possible under certain conditions of temperature, pressure etc. This might be like Salt (sodium chloride), in which positive ions of sodium and negative ions of chlorine adopt a face centered cubic lattice of alternating ions, with electrostatic forces (negative attracts positive, etc) holding them together. This makes the material solid and regular, and is the best way to arrange the atoms to give back energy in bonding and stabilise them.
Another example might be oxygen, O2. Oxygen shares electrons over two atoms, creating a bonding effect between them, based again, on electrostatics, where the negative electrons are attracted to the positive nuclei. This is more energetically favourable than an oxygen atom in typical conditions, and so this is how it exists as you know it. Oxygen isn't really described as sticky, as in normal conditions it is a gas. This is because of the interactions between molecules (O2). What's called Van der waals forces (momentary dipole moments - electrostatics!) hold them together, but only a small amount due to various other factors, such as the polarisibility and general size of the molecule. The van der waals interactions are weak, and so molecules are not held together strongly, therefore a gas is observed.
So how come other small molecules like water or methanol exist as liquids at room temperature? This is down again to the interactions between molecules. Both these substances are what's called 'polar', which introduces more electrostatic interactions between molecules. However, they are additionally stabilised by hydrogen bonding, which accounts for many anomalous properties of water and other substances not normally expected. This is an electrostatic interaction between lone pairs of electrons on oxygen atoms in water and hydrogen atoms in other molecules of water. It makes them 'stick' together more, as energy is minimised when it happens. Water is particularly stabilised by this, hence it having a much higher boiling point than otherwise predicted.
So this is why things 'stick'. Forces between molecules or atoms. E.g. in salt they are stong, and it has a very high melting point compared to a substance like oxygen, which is not a crystal, but diatomic, and held together by van der waals forces, or water, which is a liquid. Of course, there are kinetic effects (diamond exists at room temperature despite being metastable) and the basis of interactions is on the properties of the material itself, and is not easily described by one factor alone, it's different types of electrostatic interactions which arise due to the varying nature and properties of the elements.
If you don't understand any terms there, just look them up on google, most are more clearly explained elsewhere. Although everyone else is going on about sub-atomic particles and fusion, that's not too relevant to the question you asked, as you cant understand their significance unless you first know of the chemistry of the material, which explains why some things stick together in some ways and others dont. Though I may have got you wrong and you're actually wondering why nuclei stick together.
This is probably too much for GD!
As already stated, there are basic forces in the universe that give rise to electrostatics and mavity etc, this is fundamentally physics. The study of chemistry is much more about (though not exclusively) how these varying collections of sub-atomic particles we call elements interact with each other.
Most of the ideas learnt about structure and bonding, even up to A-level are vastly simplified, and give a rough idea, but often fall down when investigated more thoroughly.
So why do atoms 'stick'? Well once you get down to it, it's all about energy. Atoms adopt structures that minimise their energy as best as possible under certain conditions of temperature, pressure etc. This might be like Salt (sodium chloride), in which positive ions of sodium and negative ions of chlorine adopt a face centered cubic lattice of alternating ions, with electrostatic forces (negative attracts positive, etc) holding them together. This makes the material solid and regular, and is the best way to arrange the atoms to give back energy in bonding and stabilise them.
Another example might be oxygen, O2. Oxygen shares electrons over two atoms, creating a bonding effect between them, based again, on electrostatics, where the negative electrons are attracted to the positive nuclei. This is more energetically favourable than an oxygen atom in typical conditions, and so this is how it exists as you know it. Oxygen isn't really described as sticky, as in normal conditions it is a gas. This is because of the interactions between molecules (O2). What's called Van der waals forces (momentary dipole moments - electrostatics!) hold them together, but only a small amount due to various other factors, such as the polarisibility and general size of the molecule. The van der waals interactions are weak, and so molecules are not held together strongly, therefore a gas is observed.
So how come other small molecules like water or methanol exist as liquids at room temperature? This is down again to the interactions between molecules. Both these substances are what's called 'polar', which introduces more electrostatic interactions between molecules. However, they are additionally stabilised by hydrogen bonding, which accounts for many anomalous properties of water and other substances not normally expected. This is an electrostatic interaction between lone pairs of electrons on oxygen atoms in water and hydrogen atoms in other molecules of water. It makes them 'stick' together more, as energy is minimised when it happens. Water is particularly stabilised by this, hence it having a much higher boiling point than otherwise predicted.
So this is why things 'stick'. Forces between molecules or atoms. E.g. in salt they are stong, and it has a very high melting point compared to a substance like oxygen, which is not a crystal, but diatomic, and held together by van der waals forces, or water, which is a liquid. Of course, there are kinetic effects (diamond exists at room temperature despite being metastable) and the basis of interactions is on the properties of the material itself, and is not easily described by one factor alone, it's different types of electrostatic interactions which arise due to the varying nature and properties of the elements.
If you don't understand any terms there, just look them up on google, most are more clearly explained elsewhere. Although everyone else is going on about sub-atomic particles and fusion, that's not too relevant to the question you asked, as you cant understand their significance unless you first know of the chemistry of the material, which explains why some things stick together in some ways and others dont. Though I may have got you wrong and you're actually wondering why nuclei stick together.
This is probably too much for GD!
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Heating things works a charm!
I think it depends on how you define space and in how many dimensions you look at the universe. Suffice to say I wouldn't understand any concise explanation.
http://en.wikipedia.org/wiki/Shape_of_the_Universe
This http://en.wikipedia.org/wiki/Friedmann-Lemaître-Robertson-Walker
was (is) the solution. Don't know how the theory has changed since I last read the article. Again there was a bbc documentary looking at it using basic maths and logic.
edit: I should add that there is no "edge" to the universe.
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Fusion bombs have been made since the 50s.
Ah, Hydrogen bombs per chance?
I knew I couldn't have been completely factually sound!
It's probably better to say that rather than we haven't been able to - it's more of a case that it isn't yet a commercially viable option for producing energy.
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So am I getting the wrong end of the stick if I say I'm nothing more than an electromagnetic/ static force joining already existing particles together? What is it that creates the force?
Thanks Ghost,
But, i've already read those and know them well. I have an exam on cosmology on tuesday lol.
The universe is expanding but not into anything per say so space is being created where there wasn't but a mechanism for this isn't clear.
sid
That's physics, and for that reason, as a chemist, i'm out!
Imbalance of charge creates the force.
Ah, Hydrogen bombs per chance?
I knew I couldn't have been completely factually sound!
It's probably better to say that rather than we haven't been able to - it's more of a case that it isn't yet a commercially viable option for producing energy.
We can do it, we just can't control it to produce energy in a useful way, like we can with fission. We can make fusion go bang, but not fizz. Which is okay for bombs, but not for powering our homes.
Exchange particles are what you are thinking of, they are usually bosons, a la Higg's.
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Indeed, that's the basis of it, but why and how that force exists is beyond me i'm afraid. Any physicists here to tell us why different charges attract and like charges repel? It sounds more simple than it actually is I think. My A-level physics teacher was an absolute joke, and i've done no 'proper' physics since getting to uni!
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Can you explain? What makes an imbalanced charge? Or any sort of charge for that matter?
Damned iphone and fat fingers
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Of course we can use it to produce energy, what do you think makes the big nuclear bombs go "bang" ?
We just can't use that energy in a useful way
Missing various steps...
Its all about hard spheres and electrostatics
Then its all about electron orbitals
Then its all about quantum mechanics
After which you get quantum field theory.
Probably worse things after this.
I failed my degree partway through quantum mechanics.
Every step you go through things make less intuitive sense, mathematics become more obscene, and correlation with experiment improves. I can get roughly as far as quantum tunneling before I give up and want to play with a milling machine instead
Its all about hard spheres and electrostatics
Then its all about electron orbitals
Then its all about quantum mechanics
After which you get quantum field theory.
Probably worse things after this.
I failed my degree partway through quantum mechanics.
Every step you go through things make less intuitive sense, mathematics become more obscene, and correlation with experiment improves. I can get roughly as far as quantum tunneling before I give up and want to play with a milling machine instead
Of course we can use it to produce energy, what do you think makes the big nuclear bombs go "bang" ?
We just can't use that energy in a useful way
I thought that it was clear that that is exactly what I meant, evidently not.