Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Did carbon exist naturally in Earth?

  1. Oct 19, 2006 #1
    I was doing a test on the other day and i came across a question.The question is:

    What is the element that cannot exist naturally in Earth?


    I choose carbon,but my tuition teacher said he thinks it is sulphur.He wasn;t very sure of his answer though.So,i wonder what it is?What is the answer?
  2. jcsd
  3. Oct 19, 2006 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    "Native," or natural occurrences, of all four in elemental form are well documented; can you furnish the exact statement of the question?
  4. Oct 19, 2006 #3


    User Avatar
    Science Advisor
    Homework Helper

    I read somewhere that it was gold.
    Natural in this sense, means that it isn't a significant contsituant of the dust cloud that formed the earth.

    I have no idea of the validity of either the claim or the supporting argument.
  5. Oct 20, 2006 #4
    if the question was 100% correct

    I think gold is the best choice.
    It's a rare metal and the most heavy too, so it may have been formed by fusion of other elements.
  6. Oct 20, 2006 #5
    They're all natural elements. Just about every element (except for perhaps the larger trans-uranics) can be produced in a stellar nucleosynthesis, but the half lives of all the transuranics and technetium is small enough for it all to have decayed so that on eart, naturally ocurring elements are all Z less than or equal to 92 (and there isn't any technetium, Z = 43)
  7. Oct 20, 2006 #6
  8. Oct 21, 2006 #7
    well,to be more exact, my question is which of the four elements cannot exist in the natural state in our earth?
  9. Oct 21, 2006 #8


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Try rephrasing yourself; don't use "natural state," it isn't too clear what you mean. All four exist as "pure" (uncombined) elements; two, carbon and sulfur appear in more than one allotrope.
  10. Oct 22, 2006 #9

    The question is probably: "Which of these elements can not appear in pure form (meaning not an alloy)." If that is so, the answer is silver. Gold always appears in pure form. Sulfur appears in pure form at the edges of volcanos. Carbon is in pure form in diamonds. Only silver is always an alloy.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook