Question

Consider the isotopes 63 Zn and 63 Cu. Is β+ decay possible? Is EC possible? What is

Q.+ ? What is QEC ? [M (63 Cu) = 62.929597 u: M (63 Zn) = 62.933212 u.]

Answer 1

Is β+ decay possible, we can determine ΔM

63 Zn -> 63 Cu + e+

  ΔM = 62.933212 - 62.929597 - 5.49×10⁻⁴ = 0.003066 u (Possible)

Q+ = 0.003066 x 931.5 MeV = 2.86 MeV

63 Cu -> 63 Ni + e+

  ΔM = 62.929597 - 62.9296694 - 5.49×10⁻⁴ = -0.0006214 u (Not possible)

Is EV decay possible, we can determine ΔM

63 Zn + e^- -> 63 Cu

  ΔM = 62.933212 + 5.49×10⁻⁴ - 62.929597 = 0.004164 u (Possible)

QEC = 0.004164 x 931.5 MeV = 3.88 MeV

63 Cu + e^- -> 63 Ni

  ΔM = 62.929597 + 5.49×10⁻⁴ - 62.9296694 = 0.0004766 u (Possible)

QEC = 0.0004766 x 931.5 MeV = 0.443953 MeV