1. Not finding help here? Sign up for a free 30min 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!

Bombardment of Nitrogen-14 with an alpha particle

  1. Jun 17, 2017 #1
    Question:
    When alpha particles, having kinetic energy 3.0000 MeV bombard nitrogen-14 nuclei, oxygen-17 forms and the reaction releases a proton. Calculate the kinetic energy shared by the reaction products.
    Nitrogen-14 = 14.000307 amu
    Helium-4 = 4.00260 amu
    Oxygen-17 = 16.99913 amu
    Proton = 1.00727 amu
    1 amu = 931 MeV

    Attempt at question:
    I cannot derive the textbook answer (1.65 MeV). I found the increase in mass to be 0.00073 amu which equals 0.67963 MeV. I subtract this from 3.0000 MeV, but I got instead 2.32037 MeV. Does anyone know how to obtain the textbook solution? Thanks a lot.
     
  2. jcsd
  3. Jun 17, 2017 #2
    Hi,
    If you want to calculate the q-value of the reaction you must have a better precision in your atomic mass (see https://www-nds.iaea.org/amdc/ame2016/mass16.txt)
    If you take this mass number you will have Q=-1.192 MeV. Q <0 because the reaction is endothermic (threshold reaction)
    PSR
     
  4. Jun 17, 2017 #3

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    You should use the isotopic mass of 1H, otherwise you miss an electron (the other isotope masses are with electrons).

    If I calculate it, the reaction is not even possible.

    Edit: You have a typo in the nitrogen mass, there is one more zero than it should be.

    I get 1.81 MeV.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Bombardment of Nitrogen-14 with an alpha particle
  1. Alpha particles (Replies: 3)

  2. Alpha particle (Replies: 4)

Loading...