Nuclear Chemistry - HW PSI AP Chemistry Name 1) In balancing the nuclear reaction 238 92U 234 90E + 4 2He, the identity of element E is. A) Pu B) Np C) U D) Pa E) Th 2) This reaction is an example of. 210 84Po 206 82Pb + A) alpha decay B) beta emission C) gamma emission D) positron emission E) electron capture 3) The missing product from this reaction is. 121 53I 121 52Te + A) 4 2He B) 0-1e C) 1 0n D) 0 1e E) 0 0 4) This reaction is an example of. 41 20Ca 41 19K + A) alpha decay B) beta decay C) positron decay D) electron capture E) gamma emission 5) Nuclei above the belt of stability can lower their neutron-to-proton ratio by. A) beta emission B) gamma emission C) positron emission D) electron capture E) Any of the above processes will lower the neutron-to-proton ratio. 6) Bombardment of uranium-235 with a neutron generates tellurium-135, 3 neutrons, and.
A) zirconium-98. B) krypton-101. C) krypton-103. D) strontium-99. E) zirconium-99. 7) The reaction shown below is responsible for creating 14 C in the atmosphere. What is the bombarding particle? 14 7N + 14 6C + 1 1H A) alpha particle B) electron C) neutron D) positron E) proton 8) 131 I has a half-life of 8 days. Assuming you start with a 1.6 mg sample of 131 I, how many mg will remain after 16.0 days? A) 0.835 B) 0.268 C) 0.422 D) 0.440 E) 0.400 9) The decay of a radionuclide with a half-life of 4.3 x 10 5 years has a rate constant (in yr -1 ) equal to. A) 6.2 x 10 5 B) 1.6 x 10-6 C) 2.3 x 10-6 D) 2.8 x 10-3 E) 5.9 x 10-8 10) The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the mass defect (in amu) of a 60 27Co nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.) A) 27.7830 B) 0.5489 C) 0.5405 D) 0.0662 E) 0.4827 11) All atoms of a given element have the same A) mass number. B) number of nucleons. C) atomic mass. D) number of neutrons. E) atomic number.
12) Atoms containing radioactive nuclei are called A) radionuclides. B) radioisotopes. C) nucleons. D) nuclides. E) radioisophores. 13) What happens to the mass number and the atomic number of an element when it undergoes beta decay? A) Neither the mass number nor the atomic number change. B) The mass number decreases by 4 and the atomic number decreases by 2. C) The mass number does not change and the atomic number increases by 1. D) The mass number does not change and the atomic number decreases by 2. E) The mass number increases by 2 and the atomic number increases by 1. 14) Which one of the following is a correct representation of a beta particle? A) 4 2e B) 1 0β C) 0 1e D) 0-1e E) 2 4β 15) Which one of the following processes results in an increase in the atomic number? A) gamma emission B) positron emission C) beta emission D) alpha emission E) corrosion 16) Of the following processes, which one changes the atomic number? A) alpha emission B) beta emission C) electron capture D) positron emission E) All of these processes change the atomic numbers. 17) What radioactive element is used to diagnose medical conditions of the heart and arteries? A) cobalt-60 B) thallium-201 C) radium-226 D) radon-222 E) thorium-234 18) In what type of radioactive decay does the atomic number of the product increase by one?
A) alpha B) beta C) gamma D) positron emission E) electron capture 19) Which type of radioactive decay results in no change in mass number and atomic number for the starting nucleus? A) alpha B) beta C) positron emission D) electron capture E) gamma 20) What happens to the mass number and the atomic number of an element when it emits gamma radiation? A) The mass number remains unchanged while the atomic number decreases by one. B) The mass number decreases by four and the atomic number decreases by two. C) The mass number increases by four and the atomic number increases by two. D) The mass number remains unchanged while the atomic number increases by one. E) The mass number and atomic numbers remain unchanged. 21) What happens to the mass number and the atomic number of an element when it emits gamma radiation? A) The mass number remains unchanged while the atomic number decreases by one. B) The mass number decreases by four and the atomic number decreases by two. C) The mass number increases by four and the atomic number increases by two. D) The mass number remains unchanged while the atomic number increases by one. E) The mass number and atomic numbers remain unchanged. 22) The beta decay of cesium-137 has a half-life of 30.0 years. How many years must pass to reduce a 25 mg sample of cesium-137 to 8.7 mg? A) 46 B) 32 C) 3.2 D) 50 E) 52 23) The half-life for beta decay of strontium-90 is 28.8 years. A milk sample is found to contain 10.3 ppm strontium-90. How many years would pass before the strontium-90 concentration would drop to 1.0 ppm? A) 92.3 B) 0.112 C) 186 D) 96.9 E) 131
24) The half-life of 131 I is 0.220 years. How much of a 500.0 mg sample remains after 24 hours? A) 496 mg B) 560 mg C) 219 mg D) 405 mg E) 337 mg 25) The basis for the carbon-14 dating method is that A) the amount of carbon-14 in all objects is the same. B) carbon-14 is very unstable and is readily lost from the atmosphere. C) the ratio of carbon-14 to carbon-12 in the atmosphere is a constant. D) living tissue will not absorb carbon-14 but will absorb carbon-12. E) All of the above are correct. 26) The curie is a measure of the A) number of disintegrations per second of a radioactive substance. B) total energy absorbed by an object exposed to a radioactive source. C) lethal threshold for radiation exposure. D) number of alpha particles emitted by exactly one gram of a radioactive substance. E) None of the above is correct. 27) The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the mass defect (in amu) of a 60 29Ni nucleus? (The mass of a nickel-60 nucleus is 59.9308 amu.) A) 0.5449 B) 1.2374 C) 0.5491 D) 28.7930 E) 1.3066
1) E 2) A 3) D 4) C 5) A 6) A 7) C 8) E 9) B 10) B 11) E 12) B 13) C 14) D 15) C 16) E 17) B 18) B 19) E 20) E 21) C 22) A 23) D 24) A 25) C 26) A 27) C Answer Key: