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Author Topic: How is diamond formed by carbon atoms?  (Read 9467 times)

Offline jccc

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How is diamond formed by carbon atoms?
« on: 02/08/2014 09:41:07 »
Within the diamond structure, the distance between any two electrons is larger than the distance between any electron and carbon nucleus, if f=kq1q2/r^2 stands.

I cannot imagine such structure in 3d space. It seems logically impossible. 

What do you know/think? Thanks!
« Last Edit: 02/08/2014 09:59:39 by jccc »


 

Offline alancalverd

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Re: How is diamond formed by carbon atoms?
« Reply #1 on: 02/08/2014 13:53:35 »
Presumably you are talking about conduction-band electrons?
 

Offline chiralSPO

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Re: How is diamond formed by carbon atoms?
« Reply #2 on: 02/08/2014 14:34:02 »
Within the diamond structure, the distance between any two electrons is larger than the distance between any electron and carbon nucleus, if f=kq1q2/r^2 stands.

I cannot imagine such structure in 3d space. It seems logically impossible. 

What do you know/think? Thanks!

You are correct that this is logically impossible. You are incorrect in asserting that the electrons have to be farther from each other than from the nucleus. In the case of carbon, there are 6 electrons per nucleus, so there is no way for that statement to be true. I don't see how it would follow from the force equation shown...
 

Offline UltimateTheory

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Re: How is diamond formed by carbon atoms?
« Reply #3 on: 02/08/2014 14:41:53 »
jccc, density of diamond is ~3.5 g/cm^3
graphite has ~2.1-2.2 g/cm^3
Calculate from this, quantity of atoms in that volume.
Then you can calculate average distances between nucleus.
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #4 on: 02/08/2014 15:26:59 »
Presumably you are talking about conduction-band electrons?

What kind of band depends on how scientists name it. Just any bond between atoms is mystery to me.

How could electrons get to so close to each other under super strong repulsion force between them?

How could they are so farther away from strong attraction/nucleus?
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #5 on: 03/08/2014 00:08:54 »
How could we love any stuff we don't understand so much?

Bloody diamond.
 

Offline evan_au

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Re: How is diamond formed by carbon atoms?
« Reply #6 on: 03/08/2014 07:27:14 »
Quote from: jccc
How could electrons get to so close to each other under super strong repulsion force between them?

The Pauli exclusion principle says that no two electrons can share exactly the same quantum state.

However, one aspect of the quantum state is the spin direction, sometimes shown as spin up & spin down (not to be confused with up & down quarks).

This means that there can be two electrons in each atomic orbital (this applies to all elements higher than Hydrogen). This means that the wave function of two electrons frequently share the same volume of space (despite their mutual repulsion).

Maybe someone else could explain how an anti-symmetric wavefunction accomplishes this feat?
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #7 on: 04/08/2014 01:28:52 »
Let's take a look at gold atom, so many electrons around nucleus, how is another gold atom able to even get to closer? Any two au atoms should repel each other.

Maybe some gluons are escaped from the nucleus? Can we call quantum cops?
 

Offline Bill S

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Re: How is diamond formed by carbon atoms?
« Reply #8 on: 04/08/2014 13:54:33 »
Quote
Let's take a look at gold atom, so many electrons around nucleus, how is another gold atom able to even get to closer? Any two au atoms should repel each other.

Would I not be right in thinking that atoms (as distinct from ions) are neutral, so there would be no net repulsive force?
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #9 on: 04/08/2014 14:51:31 »
Quote
Let's take a look at gold atom, so many electrons around nucleus, how is another gold atom able to even get to closer? Any two au atoms should repel each other.

Would I not be right in thinking that atoms (as distinct from ions) are neutral, so there would be no net repulsive force?

Good morning, Bill.

If atoms are neutral then they will not attract or repel other atoms by EM force, they will only have gravity attraction.

Say atoms are neutral is like to say married couples are sexless, but in fact, they can have group sex at well.

The mystery is the real structure of the atom, why is positive and negative charges not discharge?

Quantum condom?
« Last Edit: 04/08/2014 16:35:34 by jccc »
 

Offline chiralSPO

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Re: How is diamond formed by carbon atoms?
« Reply #10 on: 04/08/2014 17:14:55 »
Neutral atoms do not attract each other electrostatically, the way ions would. However, especially with large atoms, like gold, there are still electrostatic forces that attract them (see London Dispersion Force: http://en.wikipedia.org/wiki/London_dispersion_force)

If gold atoms get too close, they will repel (again electrostatics and Pauli exclusion)

However, there is another attractive force that keeps the atoms together in solid or molten states of gold, where the atoms are very close to each other, but not close enough to repel strongly. This force is commonly referred to as "bonding." It is a quantum phenomenon that is responsible for all types of chemical bonding other than ionic bonds (as are found in salts like NaCl or Fe2O3. Essentially, electrons near nuclei can be described as occupying orbitals. These orbitals can be centered on a single atom, or distributed among several different atoms that are close to each other.

Please see: http://en.wikipedia.org/wiki/Covalent_bond  http://en.wikipedia.org/wiki/Molecular_orbital   http://en.wikipedia.org/wiki/Metallic_bonding
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #11 on: 04/08/2014 17:32:44 »
Neutral atoms do not attract each other electrostatically, the way ions would. However, especially with large atoms, like gold, there are still electrostatic forces that attract them (see London Dispersion Force: http://en.wikipedia.org/wiki/London_dispersion_force)

If gold atoms get too close, they will repel (again electrostatics and Pauli exclusion)

However, there is another attractive force that keeps the atoms together in solid or molten states of gold, where the atoms are very close to each other, but not close enough to repel strongly. This force is commonly referred to as "bonding." It is a quantum phenomenon that is responsible for all types of chemical bonding other than ionic bonds (as are found in salts like NaCl or Fe2O3. Essentially, electrons near nuclei can be described as occupying orbitals. These orbitals can be centered on a single atom, or distributed among several different atoms that are close to each other.

Please see: http://en.wikipedia.org/wiki/Covalent_bond  http://en.wikipedia.org/wiki/Molecular_orbital   http://en.wikipedia.org/wiki/Metallic_bonding

So that's how diamond formed?
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #12 on: 04/08/2014 19:17:40 »
I guess I asked the dumbest question in history.

No scientist is dumb enough to give away the real secret of how to use carbon to make diamond.

They tell you pressure and temperature, smoothy. 
 

Offline chiralSPO

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Re: How is diamond formed by carbon atoms?
« Reply #13 on: 04/08/2014 21:18:47 »
Yes, temperature and pressure will determine what phase of matter to expect. Every substance (even mixtures of substances) has several phases that it can be in, as determined by the temperature and pressure (not just solid, liquid, gas, supercritical fluid, plasma; but also things like diamond vs graphite--see water as an example: http://upload.wikimedia.org/wikipedia/commons/thumb/0/08/Phase_diagram_of_water.svg/700px-Phase_diagram_of_water.svg.png)

Graphite transforms into diamond at high pressures because the atoms get squeezed closer together. As the nuclei shift, the electronic structure around them changes as well.

In graphite, each carbon atom is bonded to 3 other carbon atoms, and they are all in a plane. Each atom has two electrons that are as low in energy as they can get (1s orbital). The next highest in energy (3 electrons per atom) are shared between two neighboring carbon atoms (one can think of these as sigma bonds), and the highest energy electrons (1 electron per carbon) are free to exist anywhere in the lattice (one can think of these as an extended pi bond or a conduction band).

In graphite, the bonds between carbon atoms are shorter than in diamond, but there are only three atoms bonded to an atom. In diamond there are four carbon atoms bonded to each carbon atom (except at the very edge of the diamond, but let's not think about that here...) The 2-D layers of graphite are not nearly as close to one another as the carbon atoms are to their neighbors within the plane, so as the planes are squeezed together, the highest energy electrons rearrange to accommodate the different geometry. In diamond, all of the electrons are localized to single atoms or the bonds that exist between two atoms (this is why diamond is an excellent electrical insulator while graphite is a good conductor).

It is worth pointing out that diamond does revert back to graphite (very slowly) when the pressure is released.
« Last Edit: 04/08/2014 21:20:56 by chiralSPO »
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #14 on: 04/08/2014 21:38:31 »
Graphite transforms into diamond at high pressures because the atoms get squeezed closer together. As the nuclei shift, the electronic structure around them changes as well.

How much pressure will be enough to push electrons into nucleus? Isn't between them is 99.9999 empty space and strong attraction force?

You are making circles, empty circle.

I hope we can get school money refund. Do you?
« Last Edit: 05/08/2014 19:03:27 by jccc »
 

Offline Bill S

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Re: How is diamond formed by carbon atoms?
« Reply #15 on: 04/08/2014 21:47:22 »
Quote
It is worth pointing out that diamond does revert back to graphite (very slowly) when the pressure is released.

Diamonds are not "for ever" once the pressure is off; but they stick around long enough to make it seem as though they are.
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #16 on: 05/08/2014 07:31:46 »
In graphite, each carbon atom is bonded to 3 other carbon atoms, and they are all in a plane. Each atom has two electrons that are as low in energy as they can get (1s orbital). The next highest in energy (3 electrons per atom) are shared between two neighboring carbon atoms (one can think of these as sigma bonds), and the highest energy electrons (1 electron per carbon) are free to exist anywhere in the lattice (one can think of these as an extended pi bond or a conduction band).

Is this a joke? Who seriously believe it? Or it is the best model one can get?

 

Offline evan_au

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Re: How is diamond formed by carbon atoms?
« Reply #17 on: 05/08/2014 10:55:17 »
Quote
No scientist is dumb enough to give away the real secret of how to use carbon to make diamond.
These days, patents are freely available on the web. Try:

Method of making diamonds
Method for creating diamonds via detonation by utilizing explosive formulation with a positive to neutral oxygen balance - this one doesn't apply pressure smoothly!

Quote from: jccc
How much pressure will be enough to push electrons into nucleus? Isn't between them is 99.9999% empty space and strong attraction force?

It takes the pressures found inside a supernova to form a helium, carbon and iron plasma into a neutron star.
« Last Edit: 05/08/2014 11:03:11 by evan_au »
 

Offline alancalverd

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Re: How is diamond formed by carbon atoms?
« Reply #18 on: 05/08/2014 16:38:22 »
In graphite, each carbon atom is bonded to 3 other carbon atoms, and they are all in a plane. Each atom has two electrons that are as low in energy as they can get (1s orbital). The next highest in energy (3 electrons per atom) are shared between two neighboring carbon atoms (one can think of these as sigma bonds), and the highest energy electrons (1 electron per carbon) are free to exist anywhere in the lattice (one can think of these as an extended pi bond or a conduction band).

Is this a joke? Who seriously believe it? Or it is the best model one can get?



It explains what we know about graphite, predicts what we found with pyrolytic carbon and graphene, and is consistent with the stereochemistry of all carbon compounds - including diamond. How good an explanation do you want?

As for manufacturing diamonds, there is a market for artificial diamond grit and a limited gem market for clear "GE" diamonds, but they are fairly easily distinguished from the natural product and have little impact on the absurd market for mined gem diamonds.   
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #19 on: 05/08/2014 17:34:49 »
All I care is the real structure of atoms, may carbon or gold or hydrogen.

Besides pulling out quantum laws, no one has an logical answer to:
What force keeps opposite charges apart as electron and proton in atoms?

Isn't force the mechanism for everything?



 

Offline evan_au

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Re: How is diamond formed by carbon atoms?
« Reply #20 on: 05/08/2014 18:17:21 »
Quote
Or is it the best model one can get?
Images of graphene using an atomic force microscope support this model. See here.

Quote
Isn't force the mechanism for everything?
There is a saying in physics that "Anything which is not explicitly forbidden by a law must occur (somewhere)".

Electrons collapsing into protons under human-friendly conditions is explicitly forbidden by the laws of quantum theory.

(For some humorous variations on this saying, see: http://en.wikipedia.org/wiki/Everything_which_is_not_forbidden_is_allowed#National_traditions)
 

Offline chiralSPO

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Re: How is diamond formed by carbon atoms?
« Reply #21 on: 05/08/2014 18:51:32 »

Besides pulling out quantum laws, no one has an logical answer to:
What force keeps opposite charges apart as electron and proton in atoms?


Perhaps this is a reason not to discount "quantum laws" ???
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #22 on: 05/08/2014 18:59:23 »

Besides pulling out quantum laws, no one has an logical answer to:
What force keeps opposite charges apart as electron and proton in atoms?


Perhaps this is a reason not to discount "quantum laws" ???

If that's your way of science.

You win again. Dear Friend.

The electron is super lonesome, the proton is extra honny. They love each other more than ANYthing.

Why is your God forbidden them to make love?
« Last Edit: 05/08/2014 19:11:15 by jccc »
 

Offline jccc

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Re: How is diamond formed by carbon atoms?
« Reply #23 on: 23/08/2014 14:36:24 »
So what's the answer to this simple question?

Is this a real science forum?

Am I dreaming?
 

Offline alancalverd

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Re: How is diamond formed by carbon atoms?
« Reply #24 on: 23/08/2014 19:47:56 »
All I care is the real structure of atoms, may carbon or gold or hydrogen.
But you have asked for an explanation of the structure of a compound, not an atom.
 
Quote
Besides pulling out quantum laws, no one has an logical answer to:
What force keeps opposite charges apart as electron and proton in atoms?

Quantum laws. Logic, as perceived by most people, has very little to do with the reality of atomic physics. 

Quote
Isn't force the mechanism for everything?

No. It's a macroscopic summation of the real mechanisms.

In science you have to start with what is, not what you think ought to be, and then work out how reality works.

Now let us suppose that we have six electrons that "want to be" as far from each other as possible, but in some way disposed around a nucleus. It turns out that two can occupy a spherically symmetric orbital, with paired spins. Now we need to distribute four in some sort of symmetry (because a symmetric structure will have the lowest energy). But there are other carbon atoms nearby, each with four outer electrons. So we can construct a 3-dimensional lattice in which pairs of electrons with opposite spins occupy orbitals aligned with the axes of tetrahedra with a nucleus at the center of each tetrahedron, and voila, diamond.   

Alas, this simple explanation involves paired spins, which is a quantum mechanical concept. However given that elementary quantum mechanics is over 100 years old and part of the school syllabus, I think we can be forgiven for using it. Especially as no other explanation works. 

« Last Edit: 23/08/2014 19:50:56 by alancalverd »
 

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Re: How is diamond formed by carbon atoms?
« Reply #24 on: 23/08/2014 19:47:56 »

 

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