SCI 270: On Nuclear Technology Practice Problems

1. The rest masses of 64Ni28, and 64Zn30 are 63.9280 and 63.9291 amu respectively. It is well known that 64Cu29 under goes electron emission, positron emission, and electron capture of the beta decay process. The overall half life of 64Cu29 is 12.9 h. From the energies of decay Edecay given below, evaluate the mass of 64Cu29, and complete the blanks below. (See the Lecture Notes on Radioactive Decays - transmutations of nuclides)

Note the relationship between the overall decay constant and the partial decay constant:

Overall l = S lpartial       or       lpartial = fraction * loverall

Decay
reaction
Decay
energy
MeV
Percentage Partial
half-life
Mass of 64Cu29
Cu ® b- + ____0.58 40 _____ h ______
Cu ® b+ + ____0.66 19 _____ h ______
Cu + e- ® ____ no data 41 _____ h not a blank
Comment on the two masses of Cu so evaluated:

__________________________________________________________

__________________________________________________________

_____-thermic___

2. Is the process of converting a pair of proton and antiproton into neutron and antineutron exothermic or endothermic?

How much energy is required or released in this conversion?

Mass of protonMass of neutronAmount of energy

________________

________________

________________

How can the energy be supplied or removed in this process?