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

Element abundance on earth's crust

  1. Aug 29, 2009 #1
    May any one help me on how to define the units used to define the abundance of elements on earth's crust "It's written ppb(parts per billion by weight)"
    I really fail to define that!!!
  2. jcsd
  3. Sep 5, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    One ppb is one pound per billion pounds or one gram per billion grams. There are no units since they cancel.

    ie. [STRIKE]pounds[/STRIKE] of silicon/billion [STRIKE]pounds[/STRIKE] crust = ppb silicon in earth's crust
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook