For the alternative theorists:

[Write4U]

In reply to leopold, re: your #1296 post.

Don't kill the "messenger!" Yes...you're correct. You cannot "see" something that small, without a lot of help.

If you "read the whole reference" that I mentioned, it states you would need a "scanning electron microscope" to see them.

I have doubt that a "lattice structure" of carbon could exceed "normal" parameters of definitions as an element.

I agree that I made a misjudgment with the phrase "sub-molecular"....I should have said "smaller than a molecule". (is this better?)
........

I'm not "Mr. Wizard" or "Mr. Science" and have no ambitions to be an "authority" on the internet, or anywhere else...I just mentioned something I think was on PBS a couple of years ago! Yes, leopold...I'm aware of what "carbon" and it's six known forms are. I know what a frickin' diamond is!

http://en.wikipedia.org/wiki/Diamond_cubic

DIAMOND CUBIC CRYSTAL,
The diamond cubic crystal structure is a repeating pattern of 8 atoms that certain materials may adopt as they solidify. While the first known example was diamond, other elements in group 14 also adopt this structure, including α-tin, the semiconductors silicon and germanium, and silicon/germanium alloys in any proportion.

Apparently nature did find a way to use these structures for different purposes. Is there a difference in the concepts of "adapt" and "adopt"? It is always thus. No matter how small a thing, it always seems to have certain properties which are shared by or compatible to other things. Potential uses of a structure are expressed and applied in many universal applications, if it is mathematically possible, it'll happen, maybe it already has.

When we get smaller than that we end up with "elements" (fundamental atoms) and surprise, some atoms "really

like" each other and will bond, producing "offspring". Love began long before Life....

 

[Gerry Nightingale]

In reply to leopold, re: your #1299.

Okay, leopold...."white flag" is up! All I did was mention something to paddoboy concerning (maybe) the general direction of the thread...the tremendous amounts of

itsy-bitsy "diamonds" around! Are you obliquely inferring I "made it up?" Why would I?

......

I don't want to "fight" over how excruciatingly precise it is possible to be and "parsing meanings" of what "this or that" does or does not mean.

......

FYI, Nature will do as it sees fit to do...the last time I checked, she make a molecule or an atom do the "Funky Chicken" and also make really...really small carbon "links".

I also said I MADE A MISTAKE with "sub-molecular" when I meant "smaller than a molecule" say, of water.

......

I am not going to allow you to "goad" me into hijacking this Topic with "what you think" of "how small a diamond can be".





(Thanks for reading!)

 

[Aqueous Id]

I have doubt that a "lattice structure" of carbon could exceed "normal" parameters of definitions as an element.

I agree that I made a misjudgment with the phrase "sub-molecular"....I should have said "smaller than a molecule". (is this better?)
........

No, because it makes no sense to say "a molecule is smaller than a molecule". A lattice is an patterned arrangement of atoms or molecules so it can't be said to be smaller than a molecule. I suppose we could go figure out how big the unit cell for a diamond lattice is, but it's going to be much bigger than, say, a hydrogen molecule (H[sub]2[/sub]). So it's not technically correct to say there is such a thing as diamond smaller than a molecule.

The smallest "piece" of a diamond contains 8 Carbon atoms. That's bigger than a lot of stuff.

 

[Write4U]

Sub-molecular = atomic, or elemental, or nano.

Chemical Element,
A chemical element is a pure chemical substance consisting of a single type of atom distinguished by its atomic number, which is the number of protons in its atomic nucleus. Elements are divided into metals, metalloids, and non-metals. Familiar examples of elements are carbon, nitrogen, oxygen, silicon, arsenic, aluminium, iron, copper, gold, mercury, and lead

The lightest chemical elements, including hydrogen, helium and smaller amounts of lithium, beryllium and boron, are thought to have been produced by various cosmic processes during the Big Bang and cosmic-ray spallation. Production of heavier elements, from carbon to the very heaviest elements, proceeded by stellar nucleosynthesis, and these were made available for later solar system and planetary formation by planetary nebulae and supernovae, which blast these elements into space.[1] The high abundance of oxygen, silicon, and iron on Earth reflects their common production in such stars. While most elements are generally stable, a small amount of natural transformation of one element to another also occurs in the decay of radioactive elements as well as other natural nuclear processes

http://en.wikipedia.org/wiki/Chemical_element
Does evolution already start at this scale?

Nanotechnology (sometimes shortened to "nanotech") is the manipulation of matter on an atomic, molecular, and supramolecular scale. The earliest, widespread description of nanotechnology[1][2] referred to the particular technological goal of precisely manipulating atoms and molecules for fabrication of macroscale products, also now referred to as molecular nanotechnology.

http://en.wikipedia.org/wiki/Sub-molecular_engineering

 

[Gerry Nightingale]

In reply to AIP's this "thread", re: ?

I am glad there exists a definable source "what is possible". "Wikipedia".

"It is incorrect to say a diamond can be smaller than molecule". Really? (think that thru a little more)



(Thanks for reading!)

 

[Write4U]

In reply to AIP's this "thread", re: ?

I am glad there exists a definable source "what is possible". "Wikipedia".

"It is incorrect to say a diamond can be smaller than molecule". Really? (think that thru a little more)

As I understand it: A diamond is a carbon structure, a "set" of carbon molecules, but a diamond itself is not a molecule (unless you want to call it a super-molecule) nor can it be smaller than a carbon molecule, let alone a single carbon atom.

 

[leopold]

. . . but a diamond itself is not a molecule (unless you want to call it a super-molecule) . . .

trippy needs to get in here and explain this but in my opinion a diamond is probably the only "single" molecule you will ever see with the un-aided eye.
there might be others but i can't think of any.

 

[Write4U]

trippy needs to get in here and explain this but in my opinion a diamond is probably the only "single" molecule you will ever see with the un-aided eye.
there might be others but i can't think of any.

Your question is like asking if the sun is a giant hydrogen molecule. Unless carbon is mixed with other chemicals it just is carbon. It can take so many shapes that the name "carbon molecule" is a meaningless term, other than saying, "this is a bunch of carbon atoms" or the fancier, "a carbon lattice".

Diamond allotropes,
Carbon is capable of forming many allotropes due to its valency. Well known forms of carbon include diamond and graphite. In recent decades many more allotropes and forms of carbon have been discovered and researched including ball shapes such as buckminsterfullerene and sheets such as graphene. Larger scale structures of carbon include nanotubes, nanobuds and nanoribbons. Other unusual forms of carbon exist at very high temperature or extreme pressures.

http://en.wikipedia.org/wiki/Allotropes_of_carbon

Actually carbon is not a "single" molecule at all. To actually see a single carbon molecule, you need to go down much smaller. Graphene (another form of carbon) can be seperated into a single atomic layer, but still can only be seen if collected in great quantities.

If we were to completely black out a piece of paper with a pencil, would we call it a paper covered by a single (large) carbon molecule?

This is my layman's view. If a more precise explanation is available, I'd love to hear it!.
CARBON seems to be pretty important to life on earth. It is both a giver and taker of life.

 

[leopold]

Your question is like asking if the sun is a giant hydrogen molecule. Unless carbon is mixed with other chemicals it just is carbon. It can take so many shapes that the name "carbon molecule" is a meaningless term, other than saying, "this is a bunch of carbon atoms".

http://en.wikipedia.org/wiki/Allotropes_of_carbon

a molecule is 2 or more atoms linked together.
hydrogen can be both atomic (nascent) and molecular because as soon as it's formed it combines with itself.
oxygen is the same way.
my question is: can a 50 carat pure diamond be considered a molecule.
it fits the definition.

Actually carbon is not a "single" molecule at all.

carbon is an atom, not a molecule.

If we were to completely black out a piece of paper with a pencil, would we call it a paper covered by a single (large) carbon molecule?

no.

CARBON seems to be pretty important to life on earth.

and to a lot of other things as well.

 

[Beer w/Straw]

If I had a girl, I'd want to name her that.

Fluorine.

(Yes, I am bipolar myself.)

:EDIT:

calcium fluoride, not a single atom.

 

[Write4U]

a molecule is 2 or more atoms linked together.
hydrogen can be both atomic (nascent) and molecular because as soon as it's formed it combines with itself.
oxygen is the same way.
my question is: can a 50 carat pure diamond be considered a molecule.
it fits the definition.

carbon is an atom, not a molecule.

Right, so why are we talking about carbon in terms of molecules? A 50 carat pure carbon molecule?

Molecule, wiki;

Molecules as components of matter are common in organic substances (and therefore biochemistry). They also make up most of the oceans and atmosphere. However, the majority of familiar solid substances on Earth, including most of the minerals that make up the crust, mantle, and core of the Earth, contain many chemical bonds, but are not made of identifiable molecules. Also, no typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond, quartz, or sodium chloride). The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding, which means that solid metals are also not made of molecules. In glasses (solids that exist in a vitreous disordered state), atoms may also be held together by chemical bonds without presence of any definable molecule, but also without any of the regularity of repeating units that characterises crystals.

 

[paddoboy]

Bah!!! Microscopic Diamonds!! Bah!!!!

Earth-size Diamond
http://www.universetoday.com/112769...olest-known-white-dwarf-detected/#more-112769

 

[exchemist]

trippy needs to get in here and explain this but in my opinion a diamond is probably the only "single" molecule you will ever see with the un-aided eye.
there might be others but i can't think of any.

In lieu of Trippy, I can have a go at this. I think I know what you are getting at. The structure of diamond is a 3D lattice structure with covalent bonding. If you take the view that "molecules" are collections of atoms bound by covalent bonds, then you could sort of argue that diamond is a kind of giant molecule.

The trouble is that there is really more to the definition of "molecule" than this. Normally it includes the idea that a molecule is the smallest unit of matter that exhibits the properties of the substance in question. Applying this idea to diamond is a bit problematic. A single atom does not exhibit the characteristic properties of diamond, as distinct from graphite, say. Yet it is clear that once you have a mere handful of atoms bonded into a diamond lattice, the structure will behave as diamond.

Conventionally in chemistry we tend to treat lattice structures as an alternative to molecules, i.e. atoms can combine to form either molecules or lattices.

 

[Trippy]

Conventionally in chemistry we tend to treat lattice structures as an alternative to molecules, i.e. atoms can combine to form either molecules or lattices.

On the flip side one could consider the empirical formula. It works in every other case, and is especially useful when considering, for example, sillicates and alumino silicates (which by the same logic 1 grain = 1 molecule even though there is a clearly defined molecule repeated).

 

[Write4U]

On the flip side one could consider the empirical formula. It works in every other case, and is especially useful when considering, for example, sillicates and alumino silicates (which by the same logic 1 grain = 1 molecule even though there is a clearly defined molecule repeated).

wiki,

This article is about analytical chemistry. For observation rather than theory, see Empirical relationship.

In chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound.[1] A simple example of this concept is that the empirical formula of hydrogen peroxide, or H2O2, would simply be HO.

If I understand correctly, a diamond would not be a compound, but only lattices of C atoms? This lattice can take on many forms but it is based on single C atoms at any level of magnification?

An empirical formula makes no reference to isomerism, structure, or absolute number of atoms. The empirical formula is used as standard for most ionic compounds, such as CaCl2, and for macromolecules, such as SiO2.

In contrast, the molecular formula identifies the number of each type of atom in a molecule, and the structural formula also shows the structure of the molecule. Different compounds can have the same empirical formula.

http://en.wikipedia.org/wiki/Empirical_formula

 

[Trippy]

wiki,

If I understand correctly, a diamond would not be a compound, but only lattices of C atoms? This lattice can take on many forms but it is based on single C atoms at any level of magnification?

Right, so it's empirical formula might be C or maybe C[sub]5[/sub] to distinguish it from graphite (just as Yellow sulfur is S[sub]8[/sub]).

 

[Trippy]

Actually, I got that the wrong way around.

As it turns out, the diamond unit cell looks like this:

And has the formula C[sub]7.5[/sub]

And the graphite unit cell loooks like this:

And has the formula C[sub]4[/sub]

 

[leopold]

Actually, I got that the wrong way around.

As it turns out, the diamond unit cell looks like this:

And has the formula C[sub]7.5[/sub]

the formula you mentioned implies the unit you shown isn't the smallest.

 

[exchemist]

Right, so it's empirical formula might be C or maybe C[sub]5[/sub] to distinguish it from graphite (just as Yellow sulfur is S[sub]8[/sub]).

….Though to my mind yellow sulphur is not really a fair comparison, as this actually has distinct, covalently bound, molecules, each of 8 sulphur atoms, arranged in a puckered ring. The rings then stack in the crystalline solid through the far weaker attraction of intermolecular forces. Yellow sulphur melts at 115C, reflecting the weak intermolecular attraction of the S8 rings to one another.

Diamond is more like quartz, having an extended array of full covalent bonds throughout the lattice, with no subunit any more strongly bound than the rest. In these cases any subdivision is somewhat arbitrarily based on concepts such as empirical formula or repeating units of geometry, but not the bonding. These compounds have melting points in well in excess of 1000C.

 

[exchemist]

If I had a girl, I'd want to name her that.

Fluorine.

(Yes, I am bipolar myself.)

:EDIT:

calcium fluoride, not a single atom.

Yup, this (the mineral fluorite) is another example of a lattice, though in this type the bonding is ionic rather than covalent, but is also very strong. It melts at around 1400C.

The violet colour of this specimen will be due to impurities (partial substitution of Ca by other metallic atoms).