Target Exam

CUET

Subject

Physics

Chapter

Nuclei

Question:

The mass of the chlorine ${^{}_{17}Cl}^{35}$ nucleus is 34.98 amu, which has protons of mass 17.133025 amu and neutrons of mass 18.155970 amu, The binding energy of the nucleus is nearly

Options:

287.82 MeV

270.0034 MeV

387.07 MeV

87.009845 MeV

Correct Answer:

287.82 MeV

Explanation:

The correct answer is Option (1) → 287.82 MeV

Given:

Mass of $^{35}_{17}\text{Cl}$ nucleus, $M_\text{nucleus} = 34.98\ \text{amu}$

Mass of protons: $17 \times 1.007825 = 17.133025\ \text{amu}$

Mass of neutrons: $18 \times 1.008665 = 18.155970\ \text{amu}$

Total mass of nucleons: $M_\text{nucleons} = 17.133025 + 18.155970 = 35.288995\ \text{amu}$

Mass defect: $\Delta m = M_\text{nucleons} - M_\text{nucleus} = 35.288995 - 34.98 = 0.308995\ \text{amu}$

Binding energy: $E_b = \Delta m \cdot 931.5\ \text{MeV/amu} \approx 0.309 \cdot 931.5 \approx 288\ \text{MeV}$

∴ Binding energy of $^{35}_{17}\text{Cl}$ nucleus ≈ 288 MeV