[jsmith613]

I know that a molecule consists of 1 or more atoms, but (this might sound like a stupid question), is diamond a molecule

My doubts come from here: http://wiki.answers.com/Q/How_many_carbon_atoms_make_up_one_diamond_molecule

[billnotgatez]

I do not have an answer, but I like the question.

[Borek]

A friend of mine - back in eighties - did his MS calculating (QM) how many atoms are necessary for a crystal to behave like crystal. Not that I remember anything else :-/

[MrTeo]

Well, diamond is a covalent crystal, so it's made up "only" (I use the quotes as perfect crystals are really rare and most of the crystals we get in touch with are actually full of imperfection, e.g. different atoms in the structure which sometimes give the compund a characteristic aspect, such as the color in some kinds of diamonds) of C atoms linked with covalent bonds.

So obviously we can think at it like a "giant molecule", even if it's more correct to consider it a crystal (also because we could only write C_n for its formula, as there are no fixed edeges for the atoms that can link together).

[Jules18]

I read somewhere that chemically it's almost exactly like graphite (in pencil "leads") but it's just structured a little differently and more densely. 

[Borek]

I read somewhere that chemically it's almost exactly like graphite (in pencil "leads") but it's just structured a little differently and more densely.

It is almost as precise as if you have stated that notebook after being squeezed in hydraulic press doesn't change - its elements are just structured a little bit differently and more densely.

[MrTeo]

I read somewhere that chemically it's almost exactly like graphite (in pencil "leads") but it's just structured a little differently and more densely. 

Well, in graphite there are "plane surfaces" made up of carbon atoms linked together with Van der Waals forces, which allow us to easily break those bonds and write with a pencil 

[Arctic-Nation]

Though you might not always be able to write with a pencil, you'll always be able to scratch your message with a diamond-tipped pen.

[kunjal8015]

Diamonds is not a molecule, it's a covalent network of carbonds arranged in a way that allows the diamond to form it's properties

so is graphite, graphite is also covalent network but the carbon atoms in graphite are arranged differently.

http://www.avogadro.co.uk/structure/chemstruc/network/g-molecular.htm

[billnotgatez]

@kunjal8015

So according to your definition is H₂ a molecule
Can you compare and contrast this with a diamond

[Ida Isotope]

I would consider it a molecule. If you are going more in depth you can most likely call it something else but it is a molecule.

Wouldn't the basic definition of molecule be ..2 or more atoms?

[billnotgatez]

@Ida Isotope -

What is a mixture?

[stevet]

I know from Materials chemistry that diamond is classified as a covalent solid, something similar to a form of phosphorus (i cant remember which one). I guess the arguments in this thread depends on what the accepted definitions of a molecule, mixture etc are...but a the end of the day, that is more philosophical, and really, of no importance, as long as we know what is actually going on inside the diamond, or any other structure for that matter. 

But since we are on the topic of diamonds...a question...if diamond consists of a network of tetrahedral carbon atoms bonded to 4 other tetrahedral carbon atoms, what is happening at the surface of a diamond crystal? Just something I have pondered before...

Steve

[billnotgatez]

but a the end of the day, that is more philosophical, and really, of no importance,

Philosophically speaking I would tend to disagree

 

For instance when we do calculations involving hydrogen there are times we have to look at it as H₂ rather than H

[Ida Isotope]

@Ida Isotope -

What is a mixture?

It is when 2 or more different subjects are "mixed" or combined. Not mixed chemically though.