Class 12 Physics Solved Numericals - Unit 27 Nuclear Physics

Numerical: In 9.0 days the number of radioactive nuclei decreases to one-eighth the number present initially. What is the half-life (in days) of the material? 2. The P isotope of phosphorus has a half-life of 14.28 days. What is its decay constant in units of s-1? 3. Find the binding energy (in MeV) for lithium 3Li (atomic mass = 7.016 003 u). 4. The binding energy of a nucleus is 225.0 MeV. What is the mass defect of the nucleus in atomic mass units? 5. A copper penny has a mass of 3.0 g. Determine the energy (in MeV) that would be required to break all the copper nuclei into their constituent protons and neutrons. Ignore the energy that binds the electrons to the nucleus and the energy that binds one atom to another in the structure of the metal. For simplicity, assume that all the copper nuclei are Cu (atomic mass = 62.939 598 u). 6. Write the Beta + decay process for each of the following nuclei with their proper chemical symbols including Z and A for each daughter nucleus: (a) F (b) O 7. A device used in radiation therapy for cancer contains 0.50 g of cobalt Co (59.933 819 u). The half-life of Co is 5.27 years. Determine the activity of the radioactive material.