Chemistry (B) HW Chapter 25 (Due May 23, Test May 28)
Matching
Match each item with the correct statement below.
a. / positron / d. / transuranium elementb. / alpha particle / e. / gamma radiation
c. / beta particle / f. / transmutation
____ 1. element with atomic number greater than 92
____ 2. energetic electron from decomposed neutron
____ 3. particle of charge +1 and mass equal to that of an electron
____ 4. conversion of an atom of one element to an atom of another element
Match each item with the correct statement below.
a. / fission / e. / scintillation counterb. / fusion / f. / neutron absorption
c. / Geiger counter / g. / neutron moderation
d. / radioisotope
____ 5. element with unstable nucleus
____ 6. combination of two nuclei to form a nucleus of greater mass
____ 7. process that decreases the number of slow-moving neutrons
____ 8. process that slows down neutrons so a reactor fuel can capture them to continue a chain reaction
____ 9. radiation detector that makes use of a phosphor-coated surface
____ 10. radiation detector that makes use of a gas-filled metal tube
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 11. An unstable nucleus ____.
a. / increases its nuclear mass by fission / c. / emits energy when it decaysb. / increases its half-life / d. / expels all of its protons
____ 12. Which is the most susceptible to damage from ionizing radiation?
a. / soft tissue / c. / woodb. / paper / d. / lead
____ 13. What particle is emitted in alpha radiation?
a. / electron / c. / helium nucleusb. / photon / d. / hydrogen nucleus
____ 14. A beta particle is a(n) ____.
a. / photon / c. / helium nucleusb. / electron / d. / hydrogen nucleus
____ 15. What is the change in atomic mass when an atom emits a beta particle?
a. / decreases by 2 / c. / remains the sameb. / decreases by 1 / d. / increases by 1
____ 16. What is the change in atomic mass when an atom emits gamma radiation?
a. / decreases by 2 / c. / remains the sameb. / decreases by 1 / d. / increases by 1
____ 17. What is the change in the atomic number when an atom emits an alpha particle?
a. / decreases by 2 / c. / increases by 1b. / decreases by 1 / d. / increases by 2
____ 18. What is the change in atomic number when an atom emits a beta particle?
a. / decreases by 2 / c. / increases by 2b. / decreases by 1 / d. / increases by 1
____ 19. What is the change in atomic number caused by the emission of gamma radiation?
a. / decreases by 2 / c. / remains the sameb. / decreases by 1 / d. / increases by 1
____ 20. Which of the following materials is necessary to stop an alpha particle?
a. / three feet of concrete / c. / single sheet of aluminum foilb. / three inches of lead / d. / single sheet of paper
____ 21. What particle decomposes to produce the electron of beta radiation?
a. / proton / c. / electronb. / neutron / d. / positron
____ 22. What symbol is used for beta radiation?
a. / e / c. / eb. / e / d. / e
____ 23. Which of the following materials is necessary to stop a beta particle?
a. / three feet of concrete / c. / thin pieces of woodb. / three inches of lead / d. / single sheet of paper
____ 24. Which of the following materials is most effective for stopping gamma radiation?
a. / several cm of lead / c. / single sheet of aluminum foilb. / one cm of water / d. / single sheet of paper
____ 25. Which type of ionizing radiation can be blocked by clothing?
a. / beta radiation / c. / gamma radiationb. / X radiation / d. / alpha radiation
____ 26. What is the change in atomic mass number when an atom emits an alpha particle?
a. / decreases by 2 / c. / increases by 2b. / decreases by 4 / d. / increases by 4
____ 27. What does the band of stability for atomic nuclei refer to?
a. / the ratio of protons to neutronsb. / the ratio of neutrons to protons
c. / the ratio of beta particles to neutrinos
d. / the ratio of alpha particles to beta particles
____ 28. If an isotope decays by the process of beta emission, ____.
a. / the mass number changesb. / the atomic number changes
c. / protons are given off
d. / the number of neutrons remains the same
____ 29. What particle is needed to complete this nuclear reaction?
Rn Po + _____
a. / He / c. / Hb. / e / d. / n
____ 30. How does an atom with too many neutrons relative to protons undergo radioactive decay?
a. / by emitting an alpha particle / c. / by emitting gamma radiationb. / by emitting a beta particle / d. / by emitting X radiation
____ 31. What particle does argon-39 (atomic number 18) emit when it decays to potassium-39 (atomic number 19)?
a. / neutron / c. / protonb. / electron / d. / alpha particle
____ 32. What particle is needed to complete the following nuclear equation?
Mn ____ + e
a. / Co / c. / Feb. / Mn / d. / Cr
____ 33. What particle is needed to complete the following equation?
N + ____ C + H
a. / n / c. / Heb. / e / d. / e
____ 34. What is the approximate half-life of uranium-238?
a. / hundreds of years / c. / millions of yearsb. / thousands of years / d. / billions of years
____ 35. Which of the following naturally occurring radioisotopes would be most useful in dating objects thought to be millions of years old?
a. / carbon-14; t = 5.73 10 yearsb. / potassium-40; t = 1.28 10 years
c. / thorium-234; t = 25 days
d. / radon-222; t = 3.8 days
____ 36. The production of carbon-14 ____.
a. / takes place in the upper atmosphereb. / is mostly due to fallout from nuclear explosions
c. / occurs to a large extent in nuclear reactors
d. / is caused by photosynthesis in plants
____ 37. What happens in a chain reaction?
a. / Products that start a new reaction are released.b. / Reactants that have two parts split.
c. / Products that are radioactive are lost.
d. / Radioactive reactants are deposited on control rods.
____ 38. Controlled nuclear chain reactions ____.
a. / take place in nuclear reactorsb. / are always fusion reactions
c. / never produce radioactive by-products
d. / are characteristic of atomic bombs
____ 39. Which type of coolant(s) usually is (are) used to remove heat from a nuclear reactor core?
a. / water only / c. / liquid sodium or waterb. / liquid sodium only / d. / CFCs
____ 40. Nuclear fusion ____.
a. / takes place in the sun / c. / can be controlled in the laboratoryb. / occurs at low temperatures / d. / is used in medicine
____ 41. What does neutron absorption accomplish in a nuclear reactor?
a. / It slows down the reaction.b. / It speeds up the reaction.
c. / It increases the rate of heat absorption.
d. / It recycles the fuel.
____ 42. Control rods made of ____.
a. / carbon / c. / plutoniumb. / liquid sodium / d. / cadmium
____ 43. What substances are used as moderators in a nuclear reactor?
a. / carbon and water / c. / plutonium and neptuniumb. / liquid sodium and water / d. / cadmium or other metal
____ 44. Which of the following statements is correct?
a. / Water is used to moderate (slow down) neutrons in a nuclear reactor.b. / Carbon control rods are used to absorb neutrons in a nuclear fission reaction.
c. / A very high temperature is required to initiate a nuclear fission reaction.
d. / The energy released from the sun is the result of a nuclear fission reaction.
____ 45. What type of radiation is best detected by a scintillation counter?
a. / alpha radiation only / c. / alpha and beta radiation onlyb. / gamma radiation only / d. / all types of radiation
____ 46. What instrument is used routinely to check a person's exposure to radiation?
a. / Geiger counter / c. / film badgeb. / scintillation counter / d. / moderating rod
____ 47. What is the main detector of a Geiger counter?
a. / ionizable gas in a metal tube / c. / plates of ionizable plasticb. / phosphor-covered surface / d. / potassium metal surface
____ 48. What is the main detector of a scintillation counter?
a. / ionizable gas in a metal tube / c. / plates of ionizable plasticb. / phosphor-covered surface / d. / potassium metal surface
____ 49. Radiation therapy is used to ____.
a. / study reaction mechanisms / c. / treat cancerb. / detect elements / d. / initiate neutron activation analysis
____ 50. Radioisotopes taken internally for medical reasons ____.
a. / must be eliminated from the body slowlyb. / should be fissionable isotopes
c. / are usually deposited in fat tissue
d. / should have a short half-life