Nuclei

Topics in this chapter

• Nuclear Size and Density
• Binding Energy and Nuclear Stability
• Radioactive Decay Calculations
• Nuclear Decay Modes and Radiations
• Nuclear Forces and Structure
• Nuclear Reactions and Energy

Cheat sheet

Practice questions

1. Question 1Q-813D5B

   The radius of a nucleus of mass number $A$ is given by $R = R_0 A^{1/3}$. If the radius of an aluminium nucleus ($_{13}^{27} ext{Al}$) is $3.6 ext{ fm}$, the estimated radius of a tellurium nucleus ($_{52}^{125} ext{Te}$) is:

   1. A.$5.0\text{ fm}$
   2. B.$6.0\text{ fm}$
   3. C.$4.5\text{ fm}$
   4. D.$3.6\text{ fm}$
   See the answer and solution
2. Question 2Q-1BA2BA

   What is the nuclear density of a nucleus having mass number $A$, given that $R_0 = 1.2 \times 10^{-15}\text{ m}$ and the average mass of a nucleon is $1.67 \times 10^{-27}\text{ kg}$?

   1. A.$2.3 \times 10^{17}\text{ kg m}^{-3}$
   2. B.$1.16 \times 10^{15}\text{ kg m}^{-3}$
   3. C.$2.3 \times 10^{14}\text{ kg m}^{-3}$
   4. D.$4.6 \times 10^{17}\text{ kg m}^{-3}$
   See the answer and solution
3. Question 3Q-E6824E

   The binding energy per nucleon for $_{2}^{4} ext{He}$ is $7.07 ext{ MeV}$ and for $_{3}^{7} ext{Li}$ is $5.60 ext{ MeV}$. Which of the following statements is true regarding their stability?

   1. A.$_{3}^{7}\text{Li}$ is more stable than $_{2}^{4}\text{He}$
   2. B.$_{2}^{4}\text{He}$ is more stable than $_{3}^{7}\text{Li}$
   3. C.Both are equally stable
   4. D.Stability cannot be compared using binding energy per nucleon
   See the answer and solution
4. Question 4Q-4964CB

   In a nuclear reaction, the mass of the products is less than the mass of the reactants by $0.02 ext{ u}$. The energy released in this reaction is approximately:

   1. A.$9.31\text{ MeV}$
   2. B.$18.62\text{ MeV}$
   3. C.$1.86\text{ MeV}$
   4. D.$931\text{ MeV}$
   See the answer and solution
5. Question 5Q-F7CD74

   A radioactive sample has a half-life of $5 ext{ years}$. What fraction of the original sample will remain undecayed after $15 ext{ years}$?

   1. A.$1/2$
   2. B.$1/4$
   3. C.$1/8$
   4. D.$1/16$
   See the answer and solution