Name _____________________ CHEM 1004 Homework #12 Fall 2010 (Buckley) This homework is due on Monday, December 6, at class time. 1. (5 points) Fill in the missing particle in each of the following equations. Be sure to include its mass number and atomic number. 32 16 7 4 Sn 01n 11 p ______ Be 10 e _______ 0 ______ 187 76 Os 1 e 98 42 Mo 12 H 01n _______ 1 U 01n 135 54 Xe 2 0 n _______ 235 92 2. (2 points) An important use of americium-241 is in smoke detectors. What particle is emitted when americium-241 decays to neptunium-237? 3. (3 points) The half-life of tritium (hydrogen-3) is 12.3 years. If 60 mg of tritium is released from a nuclear power plant, how many mg remain after: a. 12.3 years b. 61.5 years c. 123 years 4. Iodine-131 is commonly used in treatment and diagnosis of thyroid issues. a. Write the nuclear equation for the decomposition of iodine-131 through β particle emission. b. The half-life of iodine-131 is 8 days. If the patient initially has a dose of 10 mg of iodine-131, how much would remain after 24 days? c. If the level had to get down to 0.078 mg from 10 mg for the patient to be considered “safe”, how many days would it take to be safe?