PHYS 3330 Module 5 Self Assessment Practice Problems

Module 5 Self Assessment Practice Problems

5.1
249Cf undergoes alpha decay.
(a) Write the reaction equation.
(b) Find the energy released in the decay.
Answer: (b) 6.29 MeV
5.2
Show that the alpha-emission process 226Ra –> 222Rn + 4He is energetically possible, and calculate the kinetic energy of the emitted alpha particle. The neutral atomic masses are 226.025410 u for 226Ra, 222.017578 u for 222Rn, and 4.002603 u for 4He.
Answer: 4.87 MeV
5.3
The nuclide 60Co, an odd-odd unstable nucleus, is used in medical and industrial applications of radiation. Show that it is unstable relative to negative beta decay. The atomic masses you need are 59.933817 u for 60Co and 59.930786 u for 60Ni .
Answer: 2.82 MeV
5.4
The nuclide 57Co is an odd-even unstable nucleus. Show that it cannot undergo positive beta decay, but that it can decay by electron capture. The atomic masses you need are 56.936291 u for 57Co and
56.935394 u for 57Fe .
Answer: -0.187 MeV, 0.835 MeV
5.5
Write the complete decay equation in the complete  notation for the beta (π›½βˆ’) decay of 3H (tritium), a manufactured isotope of hydrogen used in some digital watch displays, and manufactured primarily for use in hydrogen bombs.
Answer:
5.6
A rare decay mode has been observed in which 222Ra emits a 14C nucleus.
(a) The decay equation is 222Ra β†’ 𝐴X + 14C. Identify the nuclide π΄X.
(b) Find the energy emitted in the decay. The mass of 222Ra is 222.015353 u.
Answer: (b) 33.03 MeV
5.7
126I nuclei decay may be negatron emission, positron emission, or electron capture. Write the equation for each mode of decay, and identify the daughter nuclide.
Answer:
5.8
3H (3.016050 amu) decays to 2He (3.016030 amu) by negatron emission. What is the transition energy and negatron Emax if no isomeric transitions occur?
Answer: 0.018 MeV; 0.018 MeV
5.9
Two deuterons fuse to form a triton (a nucleus of tritium) and a proton. How much energy is liberated?
Answer: 4.03 MeV
5.10
11C (11.011432 amu) decays to 11B (11.009305 amu) by positron emission and electron capture. What is the transition energy and positron Emax if no isomeric transitions occur?
Answer: 1.98 MeV; 0.96 MeV