Problem set 4
Masses and Binding Energy
1: For this exercise the mass excess is used. The needed values are:
- n: 8071.3171 keV
- 1H: 7288.97050 keV
- 4He: 2424.91656 keV
- 56Fe: -60605.4 keV
- 142Ce: -84583 keV
- 238U: 47308.9 keV
more values can be found at http://ie.lbl.gov/toi2003/MassSearch.asp
- Calculate the mass of the following nucleides: n, 1H, 56Fe, 142Ce and 238U
- Which of these nuclieds is the most stable.
- Assume that 1.00 kg 2H fuse to give pure 4He. What is the change in mass, what is the amount of energy produced (Mev and kWh)
- Assume 1.00 kg233U fission spontaniusly and that the products only are 92Rb and 128Cs and 3 netruons per fission. What is the change in mass and what is the energy produced
- Which form of energy is the most importan with fission? Is it radiation or some other form of energy?
2: Calculate the binding energy per nucleon for 24Mg by using a table or database for atomic mass excess.
3: What is the ratio between the nuclear binding energy and the electron binding energy for 23Na when the ionisation potential of natrium is 5.14 V?
4: Use Einsteins formula and calculate the mass in MeV of the following particles:
- A neutron.
- A electron.
- The atomic mass unit “u”.
5: Calculate the average binding energy, given in MeV of the nucleons in the following nuclei:
- 40Ca with mass 29.9627 u.
- 56Fe with mass 55.9352 u.
- 208Pb with mass 207.9775 u.
6: Assume that a 233U nucleon fission and you get a 131Xe nucleus and a 101Ru nucleus and 3 netruons. What is the energy ?
- 235U: 40.916 MeV.
- 131Xe: -88.421 MeV.
- 101Ru: -87.952 MeV.
- neutron: 8.071 MeV.
7: Assume that by fission of uranium we get a energy of 200 MeV per nucleus. How far can you drive a car with 1 g of 235U as fuel. When a car uses aproximatly 1L of gasoline (density 0.70 g/cm3) for every 10 km? The heat of burning for octane is 5500kj/mole and a gasoline engine can utilize 18% of the energy.
8: calculate the ammount of energy between a reaction of hydrogen and oxygen compare the energy with that of creation of He from neutrons and hydrogen (proton+electron).
G for H2O is -237 kJ/mol and 0.0303 u is liberated when two protons two neutrons and two electronse fuse to a He-atom.
9: Determine if fusion of deuterium to helium gives more or less energy per gram than fission of uranium.
10: explain why we never find more than one stable nuclide in a isobarchain of odd nummber but in a isobarchain of even number it is possible to find more.
11: explain where we can find nuclides that desintergates with both beta+ and beta-. In addition explain why they have to be nuclei with odd proton and odd neutron.