SCI 270: On Nuclear Technology Practice Problems  

8. Nuclear Reactions

  1. Is the reaction 14N + 4He ® 17O + 1H, endothermic or exothermic? Evaluate the energy, Q, of the reaction. Give this amount of energy per nuclear reaction and per mole of reactants.
    Masses: H, 1.007825; n, 1.008665; He, 4.00260; 14N, 14.00307; and 17O, 16.99914.
    Conversion factor and constant: 1 amu = 1.66053e-27 kg, c = 3.0e8 m s-1 (velocity of light).


    The reaction14N (a, p) 17O is _____-thermic

    Q = ___________ MeV/reaction

        = ___________ J/mol

  2. Is the reaction 14N (n, p) 14C endothermic or exothermic? What is the mass of 14C if the beta decay energy is 0.156 MeV? Calculate the energy of the N (n, p) C reaction.


    The reaction14N (n, p) 14C is _____-thermic

    Mass of 14C = ____________ amu

    Q = ___________ MeV/reaction

  3. Complete the following reaction by giving the symbol of the products.


    14B ( , b) ________

    18N ( , b a) ________

    9Be (6Li, p) ________

    9Be (7Li, d) ________

    11B (a, p) ________

    12C (a, 2p) ________

    12C (t, p) ________

    13C (d, p) ________

    13C (t, d) ________

    Notes: a = 4He, b = 0e-, p = 1H, d = 2D, t = 3T.

     

  4. Cobalt has only one stable isotope, 59Co, whose atomic mass is 58.9332 amu. According to the Handbook of Chemistry and Physics, the cross sections for the reaction 59Co (n, g) 60 mCo reaction is 20 b; the cross sections for the reaction 59Co (n, g) 60Co reaction is 17 b; the half life of 60mCo ( , g)60Co is 10.5 m; the half life of 60Co ( , b (followed by g)) 60Ni is 5.26 y; and the decay energy of 60Co 2.819 MeV. Estimate the amount of each produced, including those nuclei that have decayed during the time when 59.0 g of 59Co is irradiated by neutrons with an intensity of 1.0e15 neutron cm-2 s-1 in a nuclear reactor for 60 seconds. Assume all nuclei begin to decay after the irradiation is finished. Estimate the number of nuclei left after 24 hours.

    Reaction Cross
    section
    Number of
    nuclei produced
    Number of Nuclei
    remain after 24 hours
    59Co (n, g) 60 mCo 20 b
    __________

    __________
    59Co (n, g) 60Co 17 b
    __________

    __________

  5. What are transuranium elements and transactinide elements? Give two nuclear reaction equations, one for the synthysis of a transuranium element, and one for the synthesis of a transactinide element. Explain your nuclear reactions for their synthesis.

    Reaction for the synthesis of a transuranium element
    __________________
    Reaction for the synthesis of a transactinide element
    __________________

  6. Why neutrons are the most important particles for the induction of nuclear reactions? What is a neutron source? What methods have been used to produce neutrons as neutron sources? What feature(s) shall be considered regarding the selection of a neutron source and why?

    No need to answer, just a guide for your study
    Answers to Practice Problems 8 are available, but do your part first. Your skills are tested and they are yours forever.

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