Francium has isotopes so how can it's atomic mass be a whole number?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
2
down vote

favorite












Why do francium, radon, radium, and actinium have whole numbers for average atomic mass even though they have isotopes? But then elements like beryllium, fluorine, and sodium are listed as having no isotopes but yet they have a decimal for their average atomic mass?










share|improve this question









New contributor




M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.















  • 1




    The Wikipedia data for Francium, Radon, Radium, and Actinium has mass numbers (protons + neutrons) not atomic masses since all the isotopes of these elements are radioactive.
    – MaxW
    56 mins ago










  • Elemant's names aren't capitalised.
    – Mithoron
    1 min ago














up vote
2
down vote

favorite












Why do francium, radon, radium, and actinium have whole numbers for average atomic mass even though they have isotopes? But then elements like beryllium, fluorine, and sodium are listed as having no isotopes but yet they have a decimal for their average atomic mass?










share|improve this question









New contributor




M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.















  • 1




    The Wikipedia data for Francium, Radon, Radium, and Actinium has mass numbers (protons + neutrons) not atomic masses since all the isotopes of these elements are radioactive.
    – MaxW
    56 mins ago










  • Elemant's names aren't capitalised.
    – Mithoron
    1 min ago












up vote
2
down vote

favorite









up vote
2
down vote

favorite











Why do francium, radon, radium, and actinium have whole numbers for average atomic mass even though they have isotopes? But then elements like beryllium, fluorine, and sodium are listed as having no isotopes but yet they have a decimal for their average atomic mass?










share|improve this question









New contributor




M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











Why do francium, radon, radium, and actinium have whole numbers for average atomic mass even though they have isotopes? But then elements like beryllium, fluorine, and sodium are listed as having no isotopes but yet they have a decimal for their average atomic mass?







physical-chemistry






share|improve this question









New contributor




M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 1 min ago









Mithoron

3,59782744




3,59782744






New contributor




M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 1 hour ago









M Floehr

141




141




New contributor




M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






M Floehr is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







  • 1




    The Wikipedia data for Francium, Radon, Radium, and Actinium has mass numbers (protons + neutrons) not atomic masses since all the isotopes of these elements are radioactive.
    – MaxW
    56 mins ago










  • Elemant's names aren't capitalised.
    – Mithoron
    1 min ago












  • 1




    The Wikipedia data for Francium, Radon, Radium, and Actinium has mass numbers (protons + neutrons) not atomic masses since all the isotopes of these elements are radioactive.
    – MaxW
    56 mins ago










  • Elemant's names aren't capitalised.
    – Mithoron
    1 min ago







1




1




The Wikipedia data for Francium, Radon, Radium, and Actinium has mass numbers (protons + neutrons) not atomic masses since all the isotopes of these elements are radioactive.
– MaxW
56 mins ago




The Wikipedia data for Francium, Radon, Radium, and Actinium has mass numbers (protons + neutrons) not atomic masses since all the isotopes of these elements are radioactive.
– MaxW
56 mins ago












Elemant's names aren't capitalised.
– Mithoron
1 min ago




Elemant's names aren't capitalised.
– Mithoron
1 min ago










2 Answers
2






active

oldest

votes

















up vote
2
down vote













For highly radioactive elements that don't occur in large quantities in nature, the mass number listed is the mass number of the most stable isotope. When this is done, the value is often written in brackets. The wikipedia page for the Periodic table has some nice details on the organization of the table and the values included.






share|improve this answer



























    up vote
    2
    down vote













    For elements with no stable isotope (i.e. Francium, Radium, and Actinium), the atomic mass is chosen to be that of the longest lived isotope.



    Sodium has more than one isotope, so that statement is not true. But more generally, the masses for stable elements are reflective of the natural abundance of each isotope in a sample of the element.






    share|improve this answer




















      Your Answer





      StackExchange.ifUsing("editor", function ()
      return StackExchange.using("mathjaxEditing", function ()
      StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
      StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
      );
      );
      , "mathjax-editing");

      StackExchange.ready(function()
      var channelOptions =
      tags: "".split(" "),
      id: "431"
      ;
      initTagRenderer("".split(" "), "".split(" "), channelOptions);

      StackExchange.using("externalEditor", function()
      // Have to fire editor after snippets, if snippets enabled
      if (StackExchange.settings.snippets.snippetsEnabled)
      StackExchange.using("snippets", function()
      createEditor();
      );

      else
      createEditor();

      );

      function createEditor()
      StackExchange.prepareEditor(
      heartbeatType: 'answer',
      convertImagesToLinks: false,
      noModals: true,
      showLowRepImageUploadWarning: true,
      reputationToPostImages: null,
      bindNavPrevention: true,
      postfix: "",
      imageUploader:
      brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
      contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
      allowUrls: true
      ,
      onDemand: true,
      discardSelector: ".discard-answer"
      ,immediatelyShowMarkdownHelp:true
      );



      );






      M Floehr is a new contributor. Be nice, and check out our Code of Conduct.









       

      draft saved


      draft discarded


















      StackExchange.ready(
      function ()
      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fchemistry.stackexchange.com%2fquestions%2f103729%2ffrancium-has-isotopes-so-how-can-its-atomic-mass-be-a-whole-number%23new-answer', 'question_page');

      );

      Post as a guest






























      2 Answers
      2






      active

      oldest

      votes








      2 Answers
      2






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes








      up vote
      2
      down vote













      For highly radioactive elements that don't occur in large quantities in nature, the mass number listed is the mass number of the most stable isotope. When this is done, the value is often written in brackets. The wikipedia page for the Periodic table has some nice details on the organization of the table and the values included.






      share|improve this answer
























        up vote
        2
        down vote













        For highly radioactive elements that don't occur in large quantities in nature, the mass number listed is the mass number of the most stable isotope. When this is done, the value is often written in brackets. The wikipedia page for the Periodic table has some nice details on the organization of the table and the values included.






        share|improve this answer






















          up vote
          2
          down vote










          up vote
          2
          down vote









          For highly radioactive elements that don't occur in large quantities in nature, the mass number listed is the mass number of the most stable isotope. When this is done, the value is often written in brackets. The wikipedia page for the Periodic table has some nice details on the organization of the table and the values included.






          share|improve this answer












          For highly radioactive elements that don't occur in large quantities in nature, the mass number listed is the mass number of the most stable isotope. When this is done, the value is often written in brackets. The wikipedia page for the Periodic table has some nice details on the organization of the table and the values included.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered 56 mins ago









          Tyberius

          6,27731859




          6,27731859




















              up vote
              2
              down vote













              For elements with no stable isotope (i.e. Francium, Radium, and Actinium), the atomic mass is chosen to be that of the longest lived isotope.



              Sodium has more than one isotope, so that statement is not true. But more generally, the masses for stable elements are reflective of the natural abundance of each isotope in a sample of the element.






              share|improve this answer
























                up vote
                2
                down vote













                For elements with no stable isotope (i.e. Francium, Radium, and Actinium), the atomic mass is chosen to be that of the longest lived isotope.



                Sodium has more than one isotope, so that statement is not true. But more generally, the masses for stable elements are reflective of the natural abundance of each isotope in a sample of the element.






                share|improve this answer






















                  up vote
                  2
                  down vote










                  up vote
                  2
                  down vote









                  For elements with no stable isotope (i.e. Francium, Radium, and Actinium), the atomic mass is chosen to be that of the longest lived isotope.



                  Sodium has more than one isotope, so that statement is not true. But more generally, the masses for stable elements are reflective of the natural abundance of each isotope in a sample of the element.






                  share|improve this answer












                  For elements with no stable isotope (i.e. Francium, Radium, and Actinium), the atomic mass is chosen to be that of the longest lived isotope.



                  Sodium has more than one isotope, so that statement is not true. But more generally, the masses for stable elements are reflective of the natural abundance of each isotope in a sample of the element.







                  share|improve this answer












                  share|improve this answer



                  share|improve this answer










                  answered 54 mins ago









                  PJ R

                  3865




                  3865




















                      M Floehr is a new contributor. Be nice, and check out our Code of Conduct.









                       

                      draft saved


                      draft discarded


















                      M Floehr is a new contributor. Be nice, and check out our Code of Conduct.












                      M Floehr is a new contributor. Be nice, and check out our Code of Conduct.











                      M Floehr is a new contributor. Be nice, and check out our Code of Conduct.













                       


                      draft saved


                      draft discarded














                      StackExchange.ready(
                      function ()
                      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fchemistry.stackexchange.com%2fquestions%2f103729%2ffrancium-has-isotopes-so-how-can-its-atomic-mass-be-a-whole-number%23new-answer', 'question_page');

                      );

                      Post as a guest













































































                      Comments

                      Popular posts from this blog

                      What does second last employer means? [closed]

                      Installing NextGIS Connect into QGIS 3?

                      One-line joke