PHYS 3330 Module 3 Self Assessment Practice Problems

Module 3 Self Assessment Practice Problems

3.1
Give the symbol for the following:
(a) the isotope of helium with mass number 4
(b) the isotope of tin with 66 neutrons
(c) an isotope with mass number 235 that contains 143 neutrons
Answer:
3.2
(a) Compute the approximate nuclear radius of carbon (A = 12), germanium (A = 70), and bismuth (A = 209).
(b) Compute the density of a typical nucleus.
(c) Find the resultant mass if we could produce a nucleus with a radius of 1 cm.
Answer: (a) 2.7 fm, 4.9 fm, 7.1 fm (b) 2 × 1017 kg∕m3 (c) 9 × 1011 kg
3.3
The most common kind of iron nucleus has mass number A = 56. Find the radius, approximate mass, and approximate density of the nucleus.
Answer: 9.3 x 10-26 kg, 4.1 x 10-43 m3, 2.3 x 1017 kg/m3
3.4
A deuterium atom is made up of a proton (atomic mass 1.007276 u), an electron (atomic mass 0.000548 u), and a neutron (atomic mass 1.008665 u). The mass of the deuterium atom is 2.014102 u. Find the energy in MeV required to bring about the disintegration of the deuterium into hydrogen plus a neutron.
Answer: 2.24 MeV
3.5
How much energy would be released if six hydrogen atoms and six neutrons were combined to form 12C?
Answer: 92.4 MeV
3.6
An antiproton is a proton with a negative charge. What energy would be emitted if a proton annihilated an antiproton?
Answer: 1876 MeV
3.7
What is the energy equivalent to the mass of an electron? Because the mass of a particle increases with velocity, assume that the electron is at rest.
Answer: 0.511 MeV
3.8
Group the following atoms as isotopes, isotones,and isobars: 131Xe, 132Xe, 130I, 133Xe, 131I, 129Te, 132I, 130Te, 131Te .
Answer:
3.9
The nuclei 11B and 11C are called mirror nuclei, because the number of protons in 11B equals the number of neutrons in 11C and the number of neutrons in 11B equals the number of protons in 11C. The atomic mass of 11C is 11.011434 u, and the atomic mass of 11B is 11.009305 u.
(a) Calculate the binding energies of 11B and 11C.
(b) Which of the two nuclei has the larger binding energy? Why is this so?
Answer: 76.3 MeV, 73.5 MeV
3.10
An alpha particle is strongly bound. The 12C nucleus might be modeled as a composite of three alpha particles. Compare the binding energy of 12C with three times the binding energy of an alpha particle. Which of these quantities is larger, and why might this be so?
Answer: 92.2 MeV, 85 MeV