User talk:Matt Arenas Mercado

Welcome!

Welcome to the Citizendium! We hope you will contribute boldly and well. Here are pointers for a quick start. You'll probably want to know how to get started as an author. Just look at CZ:Getting Started for other helpful "startup" links, and CZ:Home for the top menu of community pages. Be sure to stay abreast of events via the Citizendium-L (broadcast) mailing list (do join!) and the blog. Please also join the workgroup mailing list(s) that concern your particular interests. You can test out editing in the sandbox if you'd like. If you need help to get going, the forums is one option. That's also where we discuss policy and proposals. You can ask any constable for help, too. Me, for instance! Just put a note on their "talk" page. Again, welcome and have fun! Hayford Peirce 01:43, 13 April 2010 (UTC)

Welcome!

Thanks for contributing to inorganic chemistry. It's always pleasing to see newcomers becoming active in a helpful way. Howard C. Berkowitz 19:32, 8 October 2010 (UTC)

Matt, I echo Howard's welcome! I really appreciate your help with Inorganic chemistry. And I hope to see your finished Graphite article soon. Milton Beychok 15:07, 9 October 2010 (UTC)

Thank you very much! I saw Mr. Beychok's request for assistance in my mail. I will try my best to get Graphite up to standards. Matt Arenas Mercado 22:19, 9 October 2010 (UTC)

Re-work and expand Atoms and Molecules ??

Matt, at your earliest convenience, could you re-work/re-write/rewrite the Atoms and Molecules article? It is in very poor shape at the moment.

Also, please just call me Milt ... rather than Mr. Beychok. Milton Beychok 19:39, 19 October 2010 (UTC)

Alright, sir, if you insist... but I'd still probably call you Mr. Beychok if we ever have the pleasure of meeting in real life.

I'm sorry if it's taking me a while to get Graphite going. I'm a slow writer. I made the effort to put a structure up, though. At least, this way, it'll be easier for people to see what they can contribute to it. Matt Arenas Mercado 14:16, 21 October 2010 (UTC)

Matt, the Atoms and Molecules article has been deleted. I saved those two sections and stored them in one of my sandboxes at User:Milton_Beychok/Sandbox2. If you should come across a chemistry article that can use them, you know where they are. I also saved the image in the same place. If I should later decide to delete them, I will let you know first. Milton Beychok 04:49, 27 October 2010 (UTC)

Thanks, Milt. I made a copy of the page on my computer to save you the trouble of notifying me. If there's anything else you need help with, just ask. Matt Arenas Mercado 14:56, 27 October 2010 (UTC)

Definition of allotropy/Graphite as an allotrope

Carbon allotropes

Yes, graphite is an allotrope of carbon. According to wisegeek there are 8:

"Carbon is the substance with the greatest number of allotropes, with 8 discovered so far....

These allotropes include the amorphous carbon allotrope, carbon nanofoam, carbon nanotube, the diamond allotrope, fullerene allotrope, graphite, lonsdaleite, and ceraphite allotrope. Coal and soot are both both forms of amorphous carbon, one of the most common carbon allotropes."

I am familiar with graphite, diamond, carbon nanotubes and fullerene, but I would have to look up the others. David E. Volk 01:07, 10 November 2010 (UTC)

Some references for 'allotrope'

Allotrope

Reads as follows:

Allotropes are two or more forms of the same element in the same physical state (solid, liquid, or gas) that differ from each other in their physical, and sometimes chemical, properties. The most notable examples of allotropes are found in groups 14, 15, and 16 of the periodic table. Gaseous oxygen, for example, exists in three allotropic forms: monatomic oxygen (O), a diatomic molecule (O2), and in a triatomic molecule known as ozone (O3).

A striking example of differing physical properties among allotropes is the case of carbon. Solid carbon exists in two allotropic forms: diamond and graphite. Diamond is the hardest naturally occurring substance and has the highest melting point (more than 6,335°F [3,502°C]) of any element. In contrast, graphite is a very soft material, the substance from which the "lead" in lead pencils is made.

The allotropes of phosphorus illustrate the variations in chemical properties that may occur among such forms. White phosphorus, for example, is a waxy white solid that bursts into flame spontaneously when exposed to air. It is also highly toxic. On the other hand, a second allotrope of phosphorus known as red phosphorus is far more stable, does not react with air, and is essentially nontoxic.

Allotropes differ from each other structurally depending on the number of atoms in a molecule of the element. There are allotropes of sulfur, for example, that contain 2, 6, 7, 8, 10, 12, 18, and 20 atoms per molecule (formulas S2 to S20). Several of these, however, are not very stable.

The term allotrope was first suggested by Swedish chemist J. J. Berzelius (1779-1848). He took the name from the Greek term allotropos, meaning other way. Berzelius was unable to explain the structure of allotropes, however. The first step in that direction was accomplished by British father and son crystallographers W. H. and L.W. Bragg in 1914. The Braggs used x-ray diffraction to show that diamond and graphite differ from each other in their atomic structure.

Also see our Chemical elements article. Section under 'Allotropes' has another reference for allotropes, which gives more allotropes of carbon than above.

I'll see what more I can find for you. Anthony.Sebastian 03:44, 10 November 2010 (UTC)

Thanks for the responses.

Do you know of a definition stating whether or not the atoms of an allotrope have to be bonded covalently througout? Graphite has a layered structure with the layers not bound covalently. There has been a lot of effort towards the isolation of the graphite layers, graphene, lately link, link, link and I would like to refer to an allotrope definition that can clearly define the relationship between the two: is graphene another allotrope or just a graphite layer etc.? Matt Arenas Mercado 12:10, 11 November 2010 (UTC)

I recently read that carbon has some 40 allotropes. It would not surprise me if both graphene and graphite qualify as allotropes, as both have their different structural configurations. I'll track down the reference for you. Anthony.Sebastian 22:30, 11 November 2010 (UTC)

Anthony, I've seen your edit at the allotrope article. My university's library doesn't carry McMurry, Fay's General Chemistry: Atoms First, yet. Did it supply a definition of allotropy?

If graphene is another allotrope, graphite would be unique among other allotropes - for it to be made up of another allotrope. Matt Arenas Mercado 02:30, 14 November 2010 (UTC)

Matt, here, some additional links re graphene, some with links for further information. Bottom line, many label graphene as a carbon allotrope, usually without critical justification; others say it's not an allotrope of carbon, and explain why it is not.

How Graphene Could Revolutionize Electronics.

It is not an allotrope of carbon because the sheet is of finite size:::::, and because and other elements appear at the edge in nonvanishing stoichiometric ratios; a typical graphene would have the chemical formula C62H20. Graphenes are the 2-D counterparts of 3-D graphite.

Patent application title: GRAPHENE-BASED TRANSISTOR.

Graphene not a carbon allotrope.

Pauling’s dreams for graphene.

List of references on graphene from physics journals.

My bottom line. Graphene itself comes in several/many different forms. Whether some are or are not 'allotropes of carbon' seems not to be a key issue. I'd discuss graphene in relation to graphite without making a point about whether it's a carbon allotrope, or be non-committal about it.

I'll get back to you soon about what I can find re definitions of allotrophy. Anthony.Sebastian 19:39, 14 November 2010 (UTC)

Thanks. Nonetheless, my query remains unanswered. If anybody else has a definition for allotropy related with this issue, I'm all ears. Matt Arenas Mercado 12:15, 23 November 2010 (UTC)