1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The graphs of radioactivity

  1. Jun 14, 2012 #1
    What would be the shape of an "Activity versus Number of Atoms present" graph look like... We know that A=-λN ... They are propotional but there is a negative sign.. What would be the graph?? Thanks in advance!
     
  2. jcsd
  3. Jun 14, 2012 #2

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    Activity is proportional to the number of atoms with a positive constant.
     
  4. Jun 14, 2012 #3

    jtbell

    User Avatar

    Staff: Mentor

    Maybe your book does it differently, but to me, activity is a positive quantity so A = λN. Over time, the number of undecayed atoms decreases at a rate that equals the (negative of the) activity, and this is where the minus sign comes in: dN/dt = -A = -λN.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: The graphs of radioactivity
  1. Radioactive isotopes (Replies: 3)

  2. Radioactive decay (Replies: 1)

  3. Radioactivity Question (Replies: 4)

  4. Radioactive iodine (Replies: 1)

Loading...