Chemistry II, Nuclear Chemistry Worksheet                                Name: _____________________________ p. ____


1.          Explain the difference between a nuclear change and a chemical change.





2.          Write the equations for the decay of bismuth-209 AND uranium-240 by alpha emission.






3.          Give the definition of an isotope.  Give an example.






4.          Explain and describe what a nuclear transmutation does within the nucleus.






5.          How is it possible for an electron to be ejected from the nucleus?  Write a generic equation showing this occurring.






6.          What happens (within the nucleus) when an electron is “captured” by the nucleus?  Write a generic equation showing this occurring.





7.          Define: Half life







8.          The half-life of uranium-238 is 4.5 billion years and the ago of the Earth is 4.5 x 109 years.  What fraction of the uranium-238 that was present when Earth was formed still remains?







9.          Chromium-48 decays by b+ emission.  After 6 half-lives, what fraction of the original nuclei remains?







10.      A medical institution requests 1 gram of bismuth-214, which has a half-life of 20 minutes.  How many grams of bismuth-214 must be prepared if the shipping time is two hours?







11.      Why is the maximum recommended level of radiation exposure lower for women of childbearing age than for older women?






12.      Define: Fission.







13.      Explain what is needed for a chain reaction to occur.  Be sure to include “critical mass” within your explanation.







14.      How much energy (joules) is released in a nuclear reaction if the mass loss is 3.75 x 10-4 grams?











15.      One mole of thorium-233 decays by alpha emission to yield 3.3 x 103 kJ of energy,  How much energy is released when 2 grams of thorium-233 decays?  (the nuclear mass of thorium-233 is 233.1643 grams / mole).









16.   Describe the differences between somatic and genetic radiation.