Problem
In order to appreciate the various aspects of the topics discussed in this book, some
useful questions are given here. It is hoped that while attempting these questions,
some of the intricacies of the subject will get revealed in a better manner.
1. Explain the significance of the binding energy and the packing fraction in understanding the stability of a radioactive isotope.
2. For
238 U 90 , the binding energy per nucleon is 7.576 MeV. Calculate the mass of
this isotope. Mass of hydrogen is 1.008145 amu and that of neutron is 1.008986
amu, where 1 amu = 931 MeV.
3. The following atomic masses are given below:
20 F 9 = 20.006341 amu
20 Ne 10 = 19.998765 amu
20 Ne 11 = 20.015236 amu
Based on the mass consideration, suggest which of these nuclides will decay by
β-emission, γ -emission, and by orbital electron capture? Calculate the decay
energy in MeV.
4. Explain the type of decay
32 P 15 undergoes. Discuss the thermodynamic reasons
for such type of decay. Masses of a few isotopes are given for you to substantiate your discussions.
32 P 15 = 31.973908 amu,
32 Si 16 = 31.974020 amu and
32 Si 16 = 31.972074 amu.
5. Distinguish among β
− , β
+ , and k-capture decay processes. Explain the conditions under which radioactive isotopes can decay by these processes.
6. A certain radioactive substance (assume that it does not have any radioactive
parent) has a half-life of 8.0 days. What fraction of the initial amount will be left
after (i) 16 days and (ii) 39 days?
7. Define “Mass defect” and “Packing fraction”. From the masses given below,
calculate the binding energy in MeV for (i) an additional neutron to
239 Pu 94 and
(ii) an additional proton to
52 Mn 25 .
© The Author(s), 2021
M. Sharon and M. Sharon, Nuclear Chemistry,
https://doi.org/10.1007/978-3-030-62018-9
223
In order to appreciate the various aspects of the topics discussed in this book, some
useful questions are given here. It is hoped that while attempting these questions,
some of the intricacies of the subject will get revealed in a better manner.
1. Explain the significance of the binding energy and the packing fraction in understanding the stability of a radioactive isotope.
2. For
238 U 90 , the binding energy per nucleon is 7.576 MeV. Calculate the mass of
this isotope. Mass of hydrogen is 1.008145 amu and that of neutron is 1.008986
amu, where 1 amu = 931 MeV.
3. The following atomic masses are given below:
20 F 9 = 20.006341 amu
20 Ne 10 = 19.998765 amu
20 Ne 11 = 20.015236 amu
Based on the mass consideration, suggest which of these nuclides will decay by
β-emission, γ -emission, and by orbital electron capture? Calculate the decay
energy in MeV.
4. Explain the type of decay
32 P 15 undergoes. Discuss the thermodynamic reasons
for such type of decay. Masses of a few isotopes are given for you to substantiate your discussions.
32 P 15 = 31.973908 amu,
32 Si 16 = 31.974020 amu and
32 Si 16 = 31.972074 amu.
5. Distinguish among β
− , β
+ , and k-capture decay processes. Explain the conditions under which radioactive isotopes can decay by these processes.
6. A certain radioactive substance (assume that it does not have any radioactive
parent) has a half-life of 8.0 days. What fraction of the initial amount will be left
after (i) 16 days and (ii) 39 days?
7. Define “Mass defect” and “Packing fraction”. From the masses given below,
calculate the binding energy in MeV for (i) an additional neutron to
239 Pu 94 and
(ii) an additional proton to
52 Mn 25 .
© The Author(s), 2021
M. Sharon and M. Sharon, Nuclear Chemistry,
https://doi.org/10.1007/978-3-030-62018-9
223