The Sound Of Settled Science

Climate Cult 43 Comments

The periodic table? Is nothing sacred?

For the first time in history, a change will be made to the atomic weights of some elements listed on the Periodic table of the chemical elements posted on walls of chemistry classrooms and on the inside covers of chemistry textbooks worldwide.
The new table, outlined in a report released this month, will express atomic weights of 10 elements – hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine and thallium – in a new manner that will reflect more accurately how these elements are found in nature.
“For more than a century and a half, many were taught to use standard atomic weights — a single value — found on the inside cover of chemistry textbooks and on the periodic table of the elements. As technology improved, we have discovered that the numbers on our chart are not as static as we have previously believed,” says Dr. Michael Wieser, an associate professor at the University of Calgary, who serves as secretary of the International Union of Pure and Applied Chemistry‘s (IUPAC) Commission on Isotopic Abundances and Atomic Weights. This organization oversees the evaluation and dissemination of atomic-weight values.

43 Replies to “The Sound Of Settled Science”

  3. Very funny Kate.
    Next they’ll say that Pluto’s not a planet.
    Seriously though, I have no qualms with a more accurate PT. I’d imagine some sort of chart, or calculation will be devised to point students to the correct range of atomic weights; or, some type of fudge factor multiplier. Perhaps, bonus marks for a more accurate answer.

  4. I believe they already said that Pluto isn’t really a planet. Maybe they’ll change their minds again in a few decades.

  5. a century and a half of scientific concensus gone poof!
    What next, they’ll find out the earth isn’t flat and the sun doesn’t revolve around it ?

  8. In other words, we can say this change is equivalent to an editorial style-sheet ammendment?
    Now the atomic weight of card blanche would be….

  13. If I’m not mistaken this is another non-story (like the arsenic-based life fiasco). The atomic weight of an element is considered to be the weighted average of the atomic masses of the element’s isotopes, as found in nature. Each specific isotope has a specific, non-varying atomic mass. All that is happening in this update from the IUPAC is better quantification of the range of variance of the relative portions of the various isotopes as found in differing locations in nature. So what we have here is a slight improvement in the statistical presentation in the formal standard periodic table, but nothing is new here: nothing in physics or chemistry or nature has changed, no normal casual periodic tables, in textbooks for example, need be changed.

    Here’s a specific example which will perhaps help clarify the situation, for those less familiar with these matters. I’ll use Silicon for this example. The atomic mass of the 28-Si isotope is 27.976926532, and about 92.21 to 92.25% of the Si atoms occurring in nature are 28-Si. The atomic mass of the 29-Si isotope is 28.976494700, and about 4.69 to 4.67% of the Si atoms occurring in nature are 29-Si. The atomic mass of the 30-Si isotope is 29.973770171, and about 3.10 to 3.08% of the Si atoms occurring in nature are 30-Si. Previously, the atomic weight of Si was calculated by using natural abundances of 92.2297% for 28-Si, 4.6832% for 29-Si, and 3.0872% for 30-Si, so an atomic weight of 28.0854 was shown on the standard periodic table, assuming a symmetrical distribution. The change that is being made is that now the range of atomic weights for Si, from the case where there is 92.25% of the light stuff and less of the heavy stuff, to the case where there is 92.21% of the light stuff and more of the heavy stuff, will be shown in the standard periodic table, instead of a single normalized value. Something like this: [ 28.084 to 28.092 ].

  14. I have the girfriend’s marked on the calendar,and it does change from month to month,kind of like what Mr. Vίtruvious says.My advice is just to be careful what you say and do around those times.

  15. In practice, most lab applications will not change. The previous weight will be used to make solutions etc. Only a few obscure labs doing rare work might be affected by the new and improved ranges.
    On a theoretical level, like in education, there may be some implications. Everyone who has taken chemistry knows at least one teacher/prof/lab instructor who will make his poor students suffer when working out chemistry problems with these new ranges.
    After all, who can forget this true-to-life model of a sadistic science instructor instructor.
    http://www.youtube.com/watch?v=ezKkoOxbl-c&NR=1
    (if link doesn’t work)

  16. In practice, most lab applications will not change. The previous weight will be used to make solutions etc. Only a few obscure labs doing rare work might be affected by the new and improved ranges.
    On a theoretical level, like in education, there may be some implications. Everyone who has taken chemistry knows at least one teacher/prof/lab instructor who will make his poor students suffer when working out chemistry problems with these new ranges.
    After all, who can forget this true-to-life model of a sadistic science instructor :
    http://www.youtube.com/watch?v=ezKkoOxbl-c&NR=1

  17. And yet we still act based on what we (think we) know about the atomic table, despite the science behind it not being “settled.”

  18. WOW, even I understand that, Sagacious one. Thanks. You stopped me from suggesting that someone should stand athwart the PT and shout STOP. (I think that’s my first use of ‘athwart’, LOL).
    O/T, Vitruvius, but I think you’d really like Albert Jay Nock’s Memoirs of a Superfluous Man. I’m barely into it, but he strongly questions the notion that the benefits of universal literacy outweigh the costs. His view bears an uncanny resemblance to your Pathology of the Blogosphere (TM) theory.

  19. You’re welcome, Me No Dhimmi. Someone has to call out these
    bullshit stories about science, it may as well be me. I do think that
    universal literacy would be a good idea, though, or (based on blog
    data) even 50% literacy. We should try for it some day.

  21. Changing the mass standard from 16O/16 to 12C/12 to
    19F/19 has had some effect. As did the changing definition of the litre.

  22. Vivitrius has it exactly right. The idea that this is some great overturning of scientific consensus is pure bullshit. Not surprised to see Kate jumping on it, though. Anything that can be twisted to make the scientific process look bad is Good Propaganda for Komrade Kate.

  23. The change to the base for the molar mass constant from C to O to F does have some effect, John, as 12-C ÷ 12 = 12 ÷ 12 = 1.00000, 16-O ÷ 16 = 15.99491461956 ÷ 16 = 0.99968, and 19-F ÷ 19 = 18.99840322 ÷ 19 = 0.99991, but as you can see the effect is small enough to ignore for normal calculations. The definition of the liter, on the other hand, doesn’t enter into it, I don’t think: atomic weights and masses don’t depend on the volume of the substance being considered.

    And look on the bright side, Alex. At least the folks ’round these parts do correctly understand that the notion that anthropogenically produced carbon dioxide based global warming (or whatever its nom du jour is) is based on science is: fraudulent.

  24. alex;Where in the Hell do you get your info? Kate wrote nothing and yet you read something that she wrote.Are you off your meds? A proff at the Univ.of Calgary said it,and a reporter wrote it. Arent you a little defensive after Climategate and phil jones? Maybe somebody should check the good proffs numbers.

  25. This is great news!
    I can finally pass Organic Chemistry without using a balanced energy equation. Will they sell these at Staples, because that was easy!

  26. I’m having too much fun watching old Muppets Beaker and Bunsen videos.
    Changing the definition of the liter won’t effect amu or moles but it’ll certainly mess with molarity.

  27. Agreed, Bennett, yet the molarity, the molar concentration of a solution
    (usually expressed as the number of moles of solute per liter of solution)
    really doesn’t enter into the topic at hand, I don’t think.

  28. I suppose, Vίt, but I’ll take a swing at a Burke’s Connection: The post says that the periodic table is “sacred”, the periodic table is part of chemistry, chemistry includes molarity, a dyslexic may see molarity as morality, morality is related to religion and religion is sacred just like the periodic table.
    Actually the question of liters and the periodic table came up between you and John. I was just following the meandering path.

  29. As no one so far has answered Kate’s question explicitly, I will do so: N O.
    The point about the change in the litre is, I suppose, that all of this mucking about with fundamentals is a nuisance, and can lead to errors.
    Now in point of fact the litre as a cubic decimetre is satisfying in a way that the volume of a kg of water at 4 deg C and 1 atm is not.
    The litre was originally the cubic dm. Then in 1901 (according to Wikipedia) it was officially changed to the vol of a kg of water.
    But I don’t think most physicists paid any attention to the new definition – in the `60s the litre was a cubic dm in physics classes and blah blah blah in
    chemistry.

  31. No wonder none of my experiments were successful. Like being stuxnetted. Thanks consensus freaks!

  32. argggh, i spent forever working with those numbers and now they want me to change them? Is oxygen no longer to be 15.999 g/m? Hydroge no longer 1.0079 g/m?
    It’s amazing how many people we’ve flunked for not knowing things that were later proven to be false…

  34. Whats this thing about moles?The only thing that I know about moles,is that when they are following each other down a mole hole,all they can smell is molasses

  36. I haven’t a clue what this is all about either (sigh), and again, not sure I care, though I suppose someone has to.

  38. Atomic Weights, OF COURSE!!
    Why didn’t I think of it before!
    No wonder I’ve had poor sleep since y2k….

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