You are a radiation scientist working for the space agency. A Mission Coordinator asks you to design shielding to prevent monoenergetic 10 MeV electrons from interacting with a cell culture that is to be flown on an upcoming space shuttle mission. The cell culture is covered with a 1 cm thick sheet of Lucite (density = 1.19 g/cm^3) - see figure below.
a) What thickness of lead (in cm) is required on top of the Lucite to prevent the 10 MeV electrons from reaching the culture?
b) The Mission Coordinator assumes that when the electrons are shielded out, that there will be no other radiation sources interacting with the cell culture. Assuming that your spacecraft is shielded from all other external radiations, and that we consider natural radiation from the materials and personnel surrounding the culture to be inconsequential, is she correct in her assumption?
c) What would be the effect, if any, on the radiation field around the cell culture if the positions of the lead and the Lucite were swapped?
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More effective than outer shell electrons in shielding
Please see the attached file for full problem description.
1. Why are inner shell electrons more effective than outer shell electrons in shielding?
Why is the energy diagram for multi electron atoms different from that of the hydrogen atom?
2. How many electrons in a single atom can have the following quantum numbers?
n = 2 n = 3, l = 2 n = 4, l = 1 n = 3 n = 3, l = 1, ml = - 1 n = 2, l = 1, ml = 0, ms = + ½
3. Use Pauli's Exclusion Principle, the Aufbau Principle, and Hund's rule to write the correct ground state configurations for:
Zn Si Br Fe+2 Mg+2 O-1
The following electronic configurations are incorrect; write each correctly for the ground state, and identify the element.
[He]2s3 1s12s12p7 [He]2s12p7 [Ar]4s23d34p6 [Kr]4d2 [Kr]3s23p63d3
4. Write B (basic), A (acidic), or amp (amphoteric) beside each of the following oxides:
MgO SO3 Al2O3 N2O5
Write P (paramagnetic) or D (diamagnetic) beside each of the following ions:
Na+1 Fe+2 Zn+2 O-1
5. Write the number of valence electrons beside each of the following.
Cl Fe N V
In each pair circle the most metallic: Na or Al; Pb or Ge. In each pair circle the least metallic: Bi or As; Te or BrView Full Posting Details