Follow Slashdot blog updates by subscribing to our blog RSS feed


Forgot your password?

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).


Periodic Table of Elements To Get an Update 99

Posted by timothy
from the elementally-my-dear-watson dept.
Lazarian writes "Scientists from around the world have put forth an update to the Periodic Table of Elements. In particular, they are changing the manner in which atomic weights of ten elements are expressed. From the article: 'For example, sulfur is commonly known to have a standard atomic weight of 32.065. However, its actual atomic weight can be anywhere between 32.059 and 32.076, depending on where the element is found.'"
This discussion has been archived. No new comments can be posted.

Periodic Table of Elements To Get an Update

Comments Filter:
  • Again? (Score:5, Informative)

    by Hope Thelps (322083) on Saturday December 18, 2010 @02:39PM (#34601216)

    Again? [].

    • by migla (1099771)

      The title and summary of the first occurrence of the story was so bad, that they decided to give it another shot.

    • Re:Again? (Score:5, Funny)

      by PatPending (953482) on Saturday December 18, 2010 @02:54PM (#34601332)

      Previously, this story was posted from the thulium-and-thalium dept.

      This story was posted from the elementally-my-dear-watson dept.

      Please, we've already sulfured enough!

    • When all duplicate posts argon from /., it will be even borium than it is now.
    • by ascari (1400977)
      It happens periodically, as the name implies...
  • by Anonymous Coward

    Atomic weight depends on the number of neutrons, which determines the isotope. Isotopes may be found with different frequencies in different environments, but this is a far cry from saying that atomic weight changes based on the location of the atom.

  • dupe (Score:5, Insightful)

    by wizardforce (1005805) on Saturday December 18, 2010 @02:54PM (#34601330) Journal

    one can imagine the challenge now to educators and students who will have to select a single value out of an interval when doing chemistry calculations," says Dr. Fabienne Meyers, associate director of IUPAC

    not really, if it's a problem now, it was then too since these weights didn't magically change. Really, it doesn't terribly matter much as it is, the discrepancy is tiny and for most molecules, largely irrelevant. For any calculation that really reall matters, you won't be using the range on the table, you'd be measuring the isotope ratio in your sample and for times when it doesn't, well, that's self explanatory.

    • Even for most of the calculations that matter, unless there are specific reasons to be more than usually picky, we can usually get away with adopting the integer masses for the elements that we learned in Chemistry 101.
  • Ok, IANAC but... I thought an atomic mass was an approximation based upon the masses of the most common isotypes weighted based upon how frequently they occur in nature... no?

  • by Hognoxious (631665) on Saturday December 18, 2010 @02:56PM (#34601350) Homepage Journal

    While we're at it, maybe this is a good time for you colonials to finally learn how to spell?

    • by ColdWetDog (752185) on Saturday December 18, 2010 @03:06PM (#34601442) Homepage
      Just as soon as you guys learn how to cook.
      • Re: (Score:2, Insightful)

        by Anonymous Coward
        You lot have cheese in a can. I rest my case.
        • Just as I was thinking, "America--Fuck Yeah!," I realized we have Cheeze Whiz []. And we also have it in a "Light" version. Sigh.
          • Cheez-whiz isn't food, it's a 'food product'. Thus, it is more along the lines of industrial chemicals and probably should be vetted by the EPA (but that's another story).

            No, we're talking about 'cooking'. Putting presumably edible materials together in a manner that makes them palatable and nutritious. British cooking, while I will reserve judgment about nutrition (boiling vegetables until the lose all consistency can't be good for nutritional value), can certainly be faulted for palatability (Haggis,
            • by tomhudson (43916)

              Cheez-whiz isn't food, it's a 'food product'. Thus, it is more along the lines of industrial chemicals and probably should be vetted by the EPA (but that's another story).

              Cheez Whiz - something even my dogs won't eat. And dogs will eat baby diapers and "treats" from the kitty litter box. And yet parents will feed it to their kids.

              Announcer: First prize is a year's supply of Cheeze Whiz.
              Contestant: What's second prize?
              Announcer: TWO year's supply of Cheeze Whiz.

              -- Barbie

            • And don't get me started on British automobiles....

              What's wrong with Bentleys? Or Rolls-Royces? Or Jaguars? Or Land Rovers? What about Lotus?
              There are more, too.

              • He said British. Bentley are German (VW). Rolls Royce are German (BMW). Jaguar are Indian (Tata), as are Land Rover.

                • You mean their owners are. In most cases they are subsidiaries rather than brands, and in all cases their actual factories are in the UK. They don't make knock-offs of foreign designs (like Vauxhall vs Opel). They may not be all-British, but it's hard to argue that they're not British.

    • by Kozz (7764) on Saturday December 18, 2010 @03:10PM (#34601462)

      Re:Aluminium. Sulphur.

      While we're at it, maybe this is a good time for you colonials to finally learn how to spell?

      Okay, I'll feed the troll.

      The name originates from the Latin word 'sulfur' and Middle English 'sulfre' meaning brimstone. [cite []]

      On the other hand, the other word is a bit more blurry as to who "wins"

      ...In 1807, Davy proposed the name alumium for the metal, undiscovered at that time, and later agreed to change it to aluminum.

      Shortly thereafter, the name aluminium was adopted by IUPAC to conform with the "ium" ending of most elements. Aluminium is the IUPAC spelling and therefore the international standard.

      Aluminium was also the accepted spelling in the U.S.A. until 1925, at which time the American Chemical Society decided to revert back to aluminum, and to this day Americans still refer to aluminium as "aluminum".

      [cite []]

      • by magus_melchior (262681) on Saturday December 18, 2010 @04:11PM (#34601916) Journal

        One gripe I have about the IUPAC's insistence on -ium for aluminium is that they break that convention for elements like tantalum, platinum, molybdenum, and lanthanum. Y'know, if they really, REALLY wanted to be consistent, they'd rename those tantalium, platinium, molybdenium, and lanthanium.

        Of course, I can't complain too hard, as the ACS used "aluminium" until they changed their minds...

      • "The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990, but three years later recognized aluminum as an acceptable variant. Hence their periodic table includes both.[58] IUPAC prefers the use of aluminium in its internal publications, although nearly as many IUPAC publications use the spelling aluminum." []
      • by tsa (15680)

        They probably did that because it fit their Fahrenheits and their miles better.

      • In Latin, the word is variously written sulpur, sulphur, and sulfur (the Oxford Latin Dictionary lists the spellings in this order).

        Just going by this, 'sulfur' was not the universally accepted way to spell it in Latin. Either way, how it was spelt in latin (or greek) has no relevance of what is 'correct'.

        However, IUPAC adopted the spelling sulfur in 1990, as did the Royal Society of Chemistry Nomenclature Committee in 1992.

        But the international and British standards bodies recommend using sulfur anyway.

        From Wikipedia article. []

      • No most Americans refer to aluminum as tin foil.

      • by jsh1972 (1095519)
        Charles M. Hall, inventor of the electrolytic extraction method of producing the metal, used the -um suffix to reflect the fact that at the time, aluminum was a precious metal and wanted it to sound more like platinum. The Washington Monument has a pyramidal cap of aluminum, At that time aluminum was $1.00 per avoirdupois ounce. For perspective, silver was $1.30 per troy ounce ($1.18 per avoirdupois ounce); 100 ounces (about 2.8 kg) of aluminum were needed to produce the pyramid.
    • Just as soon as you guys get dentists.
    • by ZankerH (1401751)
      And for the saxon dogs to stop calling Wolfram "Tungsten". Schweinerei!
    • don't be such a pernickety scallywag over the titbit of difference. I just wanted to type the UK variants of scalawag and persnickety and tidbit.
    • If atomic weight weren't dimensionless you would be measuring it in ounces, but it would be slightly different values of ounce [] for both sides of the pond. Shame on you!

    • by celle (906675)

      " colonials to finally learn how to spell?"

      When I see all articles from you folks of the old continent spelled right and grammatically correct. By the way, which english version are we using? The Queens English handheld reference or the American English weightlifter edition. Spelling and grammar are irrelevant if the message is understood by those intended to receive said message.

      Kill all overbearing spelling and grammar checkers.(heil!)

      • by adamofgreyskull (640712) on Saturday December 18, 2010 @08:12PM (#34603356)
        Indeed, I've seen enough disgustingly mispelled words that if an American spells words correctly albeit in "American", then I couldn't care less.* A good faith effort to communicate well and be understood is there. Spelling and grammar differences *can* be annoying, but they don't harm understanding. It's the idiomatic phrases that are most ripe for misunderstanding anyway:

        "I saw a tramp smoking a fag the other day"

        Quite impressive the amount of misunderstanding that could come from such a short sentence, right? An English tramp of course, is an American bum. But an American tramp is an English slut. An English bum is an American fanny. And a fag as you should know, is of course a cigarette.) * Couldn't care less [], really, if there's one thing you get right. Please, make it this.

      • By the way, which *english* version are we using? The *Queens* English

        I'm using the one where names of countries and words derived from them are capitalized, and possessive nouns have an apostrophe.

    • We fixed that; our language is confusing enough as is.

      "The Yanks And The Brits Are Divided By A Common Language"

  • by ShooterNeo (555040) on Saturday December 18, 2010 @02:59PM (#34601370)

    Chemistry students don't need this many significant figures. Last time I took classes in that, I remember using about 4 significant figures (2 after the decimal) for everything.

    The hard part of any problem in science is solving it : performing the calculations with any arbitrary number of significant figures is trivial.

    And for real world uses, the atomic weight of an element is going to depend on exactly what ore you are using of that element. If your problem is affected by significant figures this far to the right of the decimal, you probably need data on exactly what you are working with.

    • This time they are adding unobtainium.
    • Realistically, you're usually working with reagents that are only 99% (or so) pure, as well. In that case using more than 3 significant digits is pretty meaningless.

    • well I for one as a hard-core geek I have tatooed the periodic table on my back. Now that sucks.

      It also sucks that I can only read it through two mirrors but that's something else entirely.
      • by tsa (15680)

        And you as a hardcore geek didn't think about having it tattood as a mirror image so you can read it in the mirror. That's a lot of minus points for you dude! ;)

        • by Urkki (668283)

          And you as a hardcore geek didn't think about having it tattood as a mirror image so you can read it in the mirror. That's a lot of minus points for you dude! ;)

          Clearly you're either an owl / a yoga master / supernaturally possessed, or you've never actually tried to read anything tattooed to your in your back with just one mirror...

          • Seeing your back is only a bit more of a stretch from having your head up your ass, you know.
            • by Urkki (668283)

              Seeing your back is only a bit more of a stretch from having your head up your ass, you know.

              How does mirror fit in that scenario?

              Wouldn't it hurt?

    • by vuo (156163)
      And you think because high school chemistry classes aren't affected, nothing is? Sheesh. Just consider a simple neutralization reaction for two strong electrolytes, HA + B gives [BH+][A-]. The goal is to neutralize the acid and base exactly to give a neutral mix. Let's say that either reagent contains sulfur, which is now M = 32.059 to 32.076. This is a change of 5.3e-4 units in terms of the lower value. Now if we have for example 1 mol/l solution, then we have 5.3e-4 mol/l excess. Doesn't sound like a lot
      • Except that the chemical supplier of sulfur is going to affect the mass just as much as what some table says. The updated table is an AVERAGE of possible naturally occurring sources of sulfur.

        If your experiment is this sensitive to pH you'd have to handle this problem through ongoing measurements of it, since any teensy error anywhere would cause a similar effect.

  • So they've decided to indicate isotopic variation on the periodic table? Is that really big news?

  • by Anonymous Coward

    You need the most exact weight possible whenever accelerating and deflecting atoms - has use in particle physics, plasma physics, quantum mechanics even astrophysics - real life applications range from particle accelerators, mass spectrometers to refinement of uranium...
    Why we want more data? - Because then we learn something about nature...
    And then we can start asking questions as to why the mass varies, how much ... perhaps we see a new effect (on quantum mechanical scale), or perhaps (and I hope not) the

    • by Deadstick (535032)

      Back in 1967, the International Committee for Weights and Measures recalibrated the isotope ratios for "Standard Mean Ocean Water", which is supposed to represent worldwide average values in the oceans. They named the new standard "Vienna Standard Mean Ocean Water", and redefined the Kelvin temperature scale based on its triple point.


    • You need the most exact weight possible whenever accelerating and deflecting atoms - has use in particle physics, plasma physics, quantum mechanics even astrophysics - real life applications range from particle accelerators, mass spectrometers to refinement of uranium...

      In that case, the atoms are going to deflect by discrete amounts depending on the exact isotope of each atom. None of the individual deflections are going to depend the average isotope distribution of the whole group, which is what this topic is about.

  • This dupe was totally periodictable.
  • The REAL Reason (Score:2, Offtopic)

    by chill (34294)

    The real reason is so we can now have sponsored elements. For example:

    Nitrogen, brought to you by Air Liquide!


    Gold, from Kitco. And now a word from Glen Beck on why you should by your gold from us!

  • by nbauman (624611) on Saturday December 18, 2010 @05:13PM (#34602336) Homepage Journal

    Maybe they downgraded it.

    • by VanessaE (970834)

      Of course they downgraded it - after all, it's way down there at the bottom of the table since 1941, now collecting dust with the rest of the Actinoid Series. It barely made it into the top 100. All the popular ones like oxygen, carbon, silicon, etc. are way up near the top where they belong.

    • Hmm... I can understand that Pluto is downgraded from planet... But how element may be downgraded?
  • I have a distinct feeling I've heard about this []recently.
  • So what does this have to say about the accuracy of the International Prototype Kilogram and its various copies?
  • Oh great. It's tough enough for my introductory chem students to learn how to calculate the atomic mass of a molecule from its empirical formula when all the masses on the periodic table are single scalars. Using ranges for masses requires that they now have to add truncation, rounding, averaging, or some sort of consistent choosing to that process. They're screwed. And so is anyone who has to grade their papers (i.e., me).
  • Current atomic weights are based upon the weighted average of the atomic weight of the isotope against it's abundance. Everyone who knows anything about the periodic table knows that these numbers are not absolute.

"Say yur prayers, yuh flea-pickin' varmint!" -- Yosemite Sam