{
  "version": "https://jsonfeed.org/version/1.1",
  "title": "chem-bla-ics",
  "description": "Chemblaics (pronounced chem-bla-ics) is the science that uses open science and computers to solve problems in chemistry, biochemistry and related fields.",
  "home_page_url": "https://chem-bla-ics.linkedchemistry.info/",
  "feed_url": "https://chem-bla-ics.linkedchemistry.info/2011/01/22/atomic-weights-are-not-constant.json",
  "icon": "https://chem-bla-ics.linkedchemistry.info/assets/images/chem-bla-ics_logo.png",
  "language": "en",
  "authors": [
    {
      "name": "Egon Willighagen",
      "url": "https://orcid.org/0000-0001-7542-0286",
      "_orcid": "0000-0001-7542-0286"
    }
  ],
  "items": [

    {
      "id": "https://doi.org/10.59350/jdzbx-6ne63",
      "url": "https://chem-bla-ics.linkedchemistry.info/2011/01/22/atomic-weights-are-not-constant.html",
      "title": ""Atomic weights are not constant" !!!",
      "content_html": "<p>In case you missed it, “standard atomic weights are not constants of nature”\n(doi:<a href=\"http://dx.doi.org/10.1351/PAC-REP-10-09-14\">10.1351/PAC-REP-10-09-14</a>)!\nWow, chemistry upside down. This is bigger than the new arsenic life they found!</p>\n\n<p>Calm down, calm down. Nothing to see here, move on.</p>\n\n<p>It was actually news a some weeks back, but a <a href=\"https://twitter.com/#!/MatToddChem/status/28787041277837312\">tweet by @MatToddChem</a>\nand a question by <a href=\"http://blueobelisk.shapado.com/questions/for-the-calculation-of-masses-in-open-babel-where-is-the-table-of-atomic-masses-sourced-from\">Antony on the Blue Obelisk eXchange</a>,\nmade me write up this post.</p>\n\n<p>Facts: 1. atomic weights have never been constant; 2. isotopic weight are constants\nof nature. The difference is simple, but the public was amazed last month and\nreaffirmed that science is just another religion. (In fact, the Dutch political\nwizard Wilders calls religion just a politic ideology, so, science is just politics;\nQ.E.D. :).</p>\n\n<p>Atomic weights are used to calculate the weight of samples, or, the other way\naround, how many molecules we have in 1 mg of some organic sample. Now, at this\nmacroscopic level, and looking at carbons, we have actually to do with a mix\nof, mostly I guess, <sup>12</sup>C and <sup>13</sup>C, more or less 99% and\n1% each. Now, these percentage reflect a mixture. Mixture composition has never\nbeen natural constants, so the claim by the authors of the paper is weird, to\nsay the least. In fact, it has been know for years that the isotope ratios vary\naround the world. Hence, the molecular weight of compound X is not the same\nhere as somewhere else. That’s all.</p>\n\n<p>Now, the <a href=\"http://www.blueobelisk.org\">Blue Obelisk</a> has been making this information\naggregated by IUPAC available under a permissive license. The most recent release\nstill has a MIT license, but the next release will be even more permissive an\nhave the CC0 waiver.</p>\n\n<h4>References</h4>\n<div class=\"csl-bib-body\">\n    <div class=\"csl-entry\">Wieser, M. E., &#38; Coplen, T. B. (2010). Atomic weights of the elements 2009 (IUPAC Technical Report). <i>Pure and Applied Chemistry</i>, <i>83</i>(2), 359–396. https://doi.org/10.1351/pac-rep-10-09-14 <a href=\"https://doi.org/10.1351/PAC-REP-10-09-14\">CrossRef</a> <a href=\"https://qlever.scholia.wiki/doi/10.1351/PAC-REP-10-09-14\">Scholia</a></div>\n  </div>",
      "summary": "In case you missed it, “standard atomic weights are not constants of nature” (doi:10.1351/PAC-REP-10-09-14)! Wow, chemistry upside down. This is bigger than the new arsenic life they found!",
      
      "date_published": "2011-01-22T00:10:00+00:00",
      "date_modified": "2011-01-22T00:10:00+00:00",
      "tags": ["blue-obelisk","chemistry","iupac"],
      "_references": [
        
          
          
            { "url": "https://doi.org/10.1351/PAC-REP-10-09-14", "doi": "10.1351/PAC-REP-10-09-14"
             }
            
          
        ],
      
      
      
      
      
      
        "authors": [ { "name": "Egon Willighagen", "url": "https://orcid.org/0000-0001-7542-0286" } ]
      
    }

  ]
}