Names ______Date ____ Period ____
Group Quiz – NUCLEAR CHEMISTRY
Multiple Choice – write the correct letter to the left of the number (2 points each).
____1. When low-mass nuclei combine to form more-massive nuclei, they undergo
a. radioactive decay b. fusion c. fission d. nuclear disintegration.
_____2. Which of the following symbols is used to represent beta emissions?
a. β b. H c. n d.
_____3. Which of the following symbols is used to represent gamma ray emissions?
a. e b. H c. n d.
_____4. Which of the following symbols is used to represent positron emissions?
a. e b. H c. β d.
_____5. Which of the following types of radiation has the greatest ability to penetrate matter?
a. alpha rays b. gamma rays c. beta rays d. protons
_____6. Which of the following elements undergoes nuclear fusion reactions to provide the primary source of energy from the sun?
a. uranium b. plutonium c. hydrogen d. iron
_____7. Which of the following particles causes a nuclear fission reaction in a uranium nucleus?
a. e b. H c. n d.
_____ 8. In the nuclear decay process called electron capture, what change occurs to the atomic number of the capturing atom?
a. It increases by one b. It decreases by one c. It increases by two d. It decreases by two
_____ 9. In the nuclear decay process called electron capture, what change occurs to the mass number of the capturing atom?
a. It increases by four b. It decreases by one c. It decreases by four d. It remains the same
_____ 10. When an atom undergoes radioactive decay by emitting an alpha particle, what change occurs to the atomic number of that atom?
a. It increases by one b. It decreases by one c. It increases by two d. It decreases by two
_____ 11. When an atom undergoes radioactive decay by emitting an alpha particle, what change occurs to the mass number of that atom?
a. It increases by one b. It decreases by one c. It decreases by two d. It decreases by four
_____ 12. When an atom undergoes radioactive decay by emitting a beta particle, what change occurs to the atomic number of that atom?
a. It increases by one b. It decreases by one c. It increases by two d. It decreases by two
_____ 13. When an atom undergoes radioactive decay by emitting a beta particle, what change occurs to the mass number of that atom?
a. It increases by one b. It decreases by one c. It decreases by four d. It remains the same
_____ 14. When ~Np undergoes beta decay, which of the following is produced?
a. Pu b. U c. Pa d. U
_____15. Half-life is the length of time in which half of the atoms in a sample
a. undergo radioactive decay b. undergo nuclear fission
c. undergo nuclear fusion d. react chemically
_____ 16. When an atom releases energy through gamma rays, what properties of the nucleus are changed?
a. both mass number and atomic number decrease b. mass number decreases and atomic number increases
c. both mass number and atomic number increase d. both mass number and atomic number remain constant.
_____ 17. What do scientists call the sequence of rapidly occurring reactions that result when a nuclear fission reaction produces enough neutrons to produce more fission reactions?
a. chain reaction b. nuclear fission c. electron capture d. binding energy
_____ 18. For the nuclear reaction Th à Ra + X, what is the identity of the species indicated by X?
a. electron b. neutron c. alpha particle d. proton
____19. For the nuclear reaction B + He à N + X, what is the identity of the species indicated by X?
a. electron b. neutron c. alpha particle d. proton
_____20. For the nuclear reaction Ba + X à Cs, what is the identity of the species indicated by X?
a. electron b. neutron c. alpha particle d. proton
_____21. For the nuclear reaction Fe + X à Mn, what is the identity of the species indicated by X?
a. electron b. neutron c. alpha particle d. proton
___22. For the nuclear reaction C + C à Na + X, what is the identity of the species indicated by X?
a. electron b. neutron c. alpha particle d. Hydrogen
_____23. When a heavy nucleus splits to form nuclei of intermediate mass, it undergoes
a. nuclear disintegration b. fusion c. radioactive decay d. fission
_____24. For the nuclear reaction K à Ar + X, what is the identity of the species indicated by X?
a. electron b. neutron c. alpha particle d. proton e. positron
_____25. For the nuclear reaction U à X + Th, what is the identity of the species indicated by X?
a. electron b. neutron c. alpha particle d. proton
_____26. How many half-lives are required for three quarters of the atoms in a sample to decay?
a. ¾ b. 1 ½ c. 2 d. 3
_____27. For the nuclear reaction Rn à He + X, what is the identity of the species indicated by X?
a. Rn b. Fr c. Pb d. Po
_____28. Which of the following generally move most rapidly?
a. alpha particles b. beta particles c. gamma rays d. All of the above move at equal speeds
_____29. The element formed when uranium-238 is made to capture a neutron and then undergoes beta decay is
a. plutonium (Pu) b. americium (Am) c. neptunium (Np) d. lead (Pb)
_____30. The quantity of uranium required to sustain a chain reaction is called the
a. threshold mass b. critical volume c. critical mass d. Curie mass
_____31. Which of the following scientist(s) is/are credited with discovering radioactivity?
a. Henri Becquerel b. Sir Issac Newton c. Marie and Pierre Curie d. Rosaline Franklin
_____32. Any change in the identity of an atom and in the number of protons in a nucleus is called
a. fusion b. radioactive decay c. fission d. transmutation
_____33. Transmutation has not necessarily occurred if a nucleus releases a(n)
a. alpha particle b. beta particle c. proton d. neutron
_____34. Which of the following statements is NOT true of fission?
a. Fission is started by a neutron
b. During the fission process, several neutrons are emitted
c. It produces more energy than fussion
d. A very heavy nucleus splits into several medium weight nuclei.
_____35. Which of the following tends to produce nuclei of lower mass?
a. fission only b. both fission and fusion c. fusion only d. neither fission nor fusion
_____36. Absorption of which of the following causes ordinary uranium-238 to change to uranium-239?
a. a neutron b. a proton c. an electron d. an alpha particle
_____37. In the following nuclear equation, Np à e + X, X represents which of the following?
a. U b. U c. Pu d. Pu
_____38. Which of the following are deflected LEAST by a magnetic field?
a. alpha particles b. beta particles c. gamma ray d. None of the above are deflected at all
_____39. Three of the statements below about nuclear fission and nuclear fusion are true. Which one is NOT true?
a. Nuclear fission is the type of reaction used in nuclear power plants.
b. Fusion reactions use hydrogen nuclei for fuel and fission reactions use uranium for fuel.
c. In nuclear fission, nuclei are split but in nuclear fusion nuclei are combined.
d. Scientists believe that fusion reactions produce radioactive waste that takes thousands of years to decay.
_____40. Which of the following generally have the lowest penetrating ability?
a. alpha particles b. beta particles c. gamma rays d. All of the above have the same penetrating ability
_____41. One of the nuclear symbol for an alpha particle is
a. H b. n c. e d. He
____42. In a balanced nuclear equation, the totals of which of the following must be equal on the left and right sides of the equation?
a. mass numbers only b. both mass and atomic numbers
c. atomic numbers only d. neither mass nor atomic numbers
_____43. Gamma rays are
a. electrons b. helium nuclei c. electromagnetic waves d. neutrons
_____44. Which of the following are not products of the nuclear fission of uranium?
a. neutrons b. energy c. alpha particles d. medium weight nuclei
_____45. Which of the following scientist(s) is/are credited with discovering Radium and Polonium?
a. Henri Becquerel b. Sir Issac Newton c. Marie and Pierre Curie d. Rosaline Franklin
_____46. Which of the following always decreases the number of protons by an even number?
a. fusion b. beta decay c. alpha decay d. fission
Calculations – Solve the following problems, showing ALL work (2 points each).
47. The half-life of a given isotope is 30 seconds. What mass of a 1000. gram sample will remain after 5.0 minutes? (Hint: watch your units!!)
48. After what time will only 1/32 of a sample of radon-222 remain, given that the half-life of this isotope is 3.8 days?
49. What fraction of a sample of polonium-210 (half-life = 138 days) will remain after 552 days?
50. The half-life of a given isotope is 10. years. What mass of a 100. gram sample will remain after 20. years?