Talk:Chemical element

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The first para says there are 118 elements; the third says there are 116 and goes on to say they are divided into 94 plus 23 which makes 117. Can we have a definitive number?

- Pepper 150.203.227.130 11:14, 17 October 2006 (UTC)

Element 117 hasn't been discovered yet, while 118 was just discovered. Thus, there should be 117 elements (1-116 and 118) so far discovered, of which 94 (hydrogen to plutonium) occur on Earth in at least trace quantities (astatine being the rarest, about 1 oz existing naturally on the planet).→ R Young {yakłtalk} 09:07, 20 October 2006 (UTC)



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Contents

[edit] why allotropes and isotope effect ruin the archaic definition

Allotropes -- it becomes very difficult to define which one truly represents "elemental" X. For example, which lattice structure best exemplifies "elemental nickel" -- they all have subtly different chemical properties. Or, better yet, should metallic gold or a gold nanoparticle (of which size?) should be "elemental gold"? even carbon, mundane and exquisitely important, has an infinite array of allotropes -- graphite, diamond, buckyballs of various radii, and nanotubes with varying dimensions, geometries, and even chiralities!

Isotope effect -- So even if we choose a "canonical" allotrope which represents element X, an 15O2 molecule has different properties than a 16O2 molecule. The isotope effect is glaring when dealing with hydrogen. So it still becomes possible to use chemical transformations (and a centrifuge -- is using "physics" cheating?) to break up an "element" in the old sense, and reassemble it into a set of compounds with different chemical properties.

Now if we choose a canonical allotrope and a canonical isotope, our definition of element becomes useless, since, a D2 molecule is a different element than an H2 molecule, and we lose any contextual meaning. The nice thing about the modern definition is that by not being a "clinical definition", it enables a synthesis of the commonalities observed between isotopes, leaves wiggle rome for differences amongst the same, and highlights gross differences between different elements. This is the hallmark of good definition.

Unless something new is discovered that confounds this definition, chemists will continue to use it. {{subst:unsigned2|08:05, 26 July 2005|67.124.223.202}

[edit] Great photo gallery

User:RTC/element photos is a great comparison table of all the elements.--Menchi 20:44, 2 Apr 2005 (UTC)

[edit] List?

Shouldn't there be some kind of list of all the elements, so that people could find what they wanted? Technically, the whole point of this page should be to:

  1. Tell the people about what a chemical element is
  2. Introduce the periodic table as a way to organise the elements
  3. Tell what the elements are

So... Just a suggestion... you know... {{subst:unsigned2|22:34, 8 September 2005|64.16.177.145}

  • Well, what you're describing is pretty much the Periodic Table, just expanded. Go start it and lets see what you can come up with.

CherryT 03:53, 10 October 2006 (UTC)

[edit] AMU Calculation

Hello all. I wrote a brief that explains how exactly the atomic masses for elements are calculated under the section that does breifly mention the subject of mass. I'm not quite certain how and where to leave the citation for it, any input is appreciated. I am not sure if the position within the article for my breif is appropriate, again input is appreciated. This is my first major post to Wikipedia and also my first post as a user with an account. I'm looking forward to contributing to Wikipedia.

Hi Morgana The Argent, think you’re doing a great job. Regarding your questions:
  • You could also consider to put your calculation example at Atomic mass or Atomic mass unit, and leave a shorter less detailed description in this article. However, there’s no hard rule that says so.
  • The position in the article itself seems okay to me.
Congrats on your first major post. Van helsing 14:52, 7 June 2006 (UTC)
PS. You already discovered the tilde (~~~~) thingy to sign your talk page posts?

[edit] Nonelement symbols

I move this part here now .. did not belong in Chemical Compound for sure .. might need a discussion where they d belong

Nonelements, especially in organic and organometallic chemistry, often acquire symbols which are inspired by the elemental symbols. A few examples:

Suggestion: seperate article? --Dirk Beetstra T C 06:28, 4 August 2006 (UTC)

[edit] The Origin of the Elements

I've read somewhere that current science explains the origin of the elements by stating that no elements existed (except helium and hydrogen) after bigbang, but later others formed because of the cooling and heating. Is this right? Can someone add this kind of information on the page?--Quinlan Vos 15:42, 8 October 2006 (UTC)

[edit] Naturally Occuring Substances?

I just want to verify, because on the PToE page it says that there are 90 naturally occuring elements and in a textbook I have (though it may be dated). (UPDATE) I'm replacing it: Tech. and the other 2 supposed elements are manmade. CherryT 03:56, 10 October 2006 (UTC)

  • I'm just gonna leave it at 91, if tech. has truely been discovered in nature. Where are we derving the other two elements from?

CherryT 04:03, 10 October 2006 (UTC)

Wellll...it depends on what you mean by 'naturally occuring'. Of the first 92 elements (up to uranium) there exist stable isotopes of 90. (Technetium and promethium have no stable isotopes.) On the other hand, trace amounts of a number of unstable isotopes are generated through radioactive decay. For example, promethium, technetium, neptunium, and plutonium are continuously created through the decay of naturally occurring uranium ores; all four elements have been detected there. Supernova explosions generate a wealth of even heavier (but very short-lived) radioisotopes through Supernova nucleosynthesis. TenOfAllTrades(talk) 04:15, 10 October 2006 (UTC)

Let's stop the 'traditional but incorrect' view and put it at '94 naturally occurring elements on Earth.' By definition, that would exclude those found in stars, but include the six found only naturally through radioactive decay (technetium, prometium, astatine, francium, neptunium, and plutonium). Much of the 'synthetic' or artificial label idea was inappopriately applied to technetium, plutonium, etc because they were created artificially before being discovered naturally...although with the 1925 natural discovery of technetium a possibility, that may also need revision.→ R Young {yakłtalk} 09:22, 20 October 2006 (UTC)

From the article 'transuranium element':

Of the elements with atomic numbers 1 to 92, all but four (43-technetium, 61-promethium, 85-astatine, and 87-francium) occur in easily detectable quantities on earth, having stable, or very long half life isotopes, or are created as common products of the decay of uranium.

Note that as early as the 1960's, it was known that Neptunium and Plutonium could be found in nature (see McWhirter's Encyclopedia of Facts).→ R Young {yakłtalk} 09:51, 20 October 2006 (UTC)

[edit] Heavy vs. Dense

Correct me if I'm wrong, but isn't Element 118 the densest, not the heaviest element? I mean, you can have several atoms of oxygen that would be heavier than Element 118.

Yes, dense would be correct, but heaviest is also correct as three atoms of Element 118 would weigh more than (and have more mass than, as implied by the density) three oxygen atoms. Matwilko 00:43, 29 October 2006 (UTC)

Densest would only be accurate if it had the same volume as the other elements but still weighed more. If you have the same volume of Osmium as you do Ununoctium, Osmium would weigh more as it is much more dense than Ununoctium. So the term "heaviest" is more accurate since if you have the same number of atoms of Os as you do Uuo, Uuo would weigh more as it's per atom mass is greater than that of any other element. (Jdurg 00:08, 3 December 2006 (UTC))

[edit] Definition?

Could someone clarify this for me: The definition says "A chemical element, often called simply an element, is a substance that cannot be decomposed or transformed into other chemical substances by ordinary chemical processes. All matter consists of these elements and as of 2006, 117 unique elements have been discovered or artificially created. The smallest particle of such an element is an atom, which consists of electrons centered about a nucleus of protons and neutrons". What is a "substance" here? Oxygen may exist as O2 or O3, are these substances? If they are, the can be transformed into each other by a chemicl process. If not, why the distinction between "substance" and "atom"? --Manscher 14:15, 25 October 2006 (UTC)

Should be a link to chemical substance. O2 is not the element, O is the element (although the terms are used inconsistently, even by chemists), that O does not want to be alone results indeed that oxygen is always found as chemical substances. Hope this clarifies a bit (I don't know if these examples (to mind spring: H, O, N, F, Br, I, Cl, S, P) are sufficiently covered in wikipedia). --Dirk Beetstra T C 14:25, 25 October 2006 (UTC)
Thanks, your answer fits very well with my own conception of "element". --Manscher 15:05, 25 October 2006 (UTC)


[edit] These are the ten most common elements in the Universe as measured in parts per million

"Most common elements in the Universe. These are the ten most common elements in the Universe as measured in parts per million:"

  • by mass or by number of particles? --GangofOne 00:55, 6 November 2006 (UTC)

[edit] Wrong colour in key to illustration of periodic table

The colour used for the transition metal positions in the table itself is a kind of salmon-pink, but the colour shown in the key for the transition metals seems to be the same pinkish-red that is used for the alkali metals. Kay Dekker 22:13, 20 November 2006 (UTC)

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