3. Older specifications for UF6 required that the concentration of neutron poisons be kept at manageable levels. In the 1970s, for instance, the Department of Energy required that the total thermal-neutron absorption of all neutron poisons not exceed the equivalent of 8 pm boron. Determine the concentration (in ppm or g/ KgU) equivalent to 8 pm boron: for each of the following: (a) boron; (b) cadmium; (c) dysprosium; (d) europium; (e) gadolinium; (f) samarium; (g) silver.