Download Chemistry (B) HW Chapter 25

Chemistry (B) HW Chapter 25 (Due May 23, Test May 28)
Matching
Match each item with the correct statement below.
a. positron
d. transuranium element
b. alpha particle
e. gamma radiation
c. beta particle
f. transmutation
____
____
____
____
1.
2.
3.
4.
element with atomic number greater than 92
energetic electron from decomposed neutron
particle of charge +1 and mass equal to that of an electron
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 counter
b. fusion
f. neutron absorption
c. Geiger counter
g. neutron moderation
d. radioisotope
____ 5.
____ 6.
____ 7.
____ 8.
____ 9.
____ 10.
element with unstable nucleus
combination of two nuclei to form a nucleus of greater mass
process that decreases the number of slow-moving neutrons
process that slows down neutrons so a reactor fuel can capture them to continue a chain reaction
radiation detector that makes use of a phosphor-coated surface
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 decays
b. 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. wood
b. paper
d. lead
____ 13. What particle is emitted in alpha radiation?
a. electron
c. helium nucleus
b. photon
d. hydrogen nucleus
____ 14. A beta particle is a(n) ____.
a. photon
c. helium nucleus
b. 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 same
b. 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 same
b. 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 1
b. 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 2
b. 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 same
b. 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 foil
b. three inches of lead
d. single sheet of paper
____ 21. What particle decomposes to produce the electron of beta radiation?
a. proton
c. electron
b. neutron
d. positron
____ 22. What symbol is used for beta radiation?
a. e
c.
e
b.
d.
e
e
____ 23. Which of the following materials is necessary to stop a beta particle?
a. three feet of concrete
c. thin pieces of wood
b. 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 foil
b. 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 radiation
b. 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 2
b. 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 neutrons
b. 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 changes
b. 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. H
b.
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 radiation
b. 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. proton
b. electron
d. alpha particle
____ 32. What particle is needed to complete the following nuclear equation?
Mn
____ + e
a.
c.
Co
Fe
b.
Mn
d.
Cr
____ 33. What particle is needed to complete the following equation?
N + ____
C+ H
a. n
c. He
b.
e
d.
e
____ 34. What is the approximate half-life of uranium-238?
a. hundreds of years
c. millions of years
b. 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 years
b. 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 atmosphere
b. 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 reactors
b. 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 water
b. liquid sodium only
d. CFCs
____ 40. Nuclear fusion ____.
a. takes place in the sun
c. can be controlled in the laboratory
b. 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. plutonium
b. liquid sodium
d. cadmium
____ 43. What substances are used as moderators in a nuclear reactor?
a. carbon and water
c. plutonium and neptunium
b. 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 only
b. 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 badge
b. 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 plastic
b. 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 plastic
b. phosphor-covered surface
d. potassium metal surface
____ 49. Radiation therapy is used to ____.
a. study reaction mechanisms
c. treat cancer
b. detect elements
d. initiate neutron activation analysis
____ 50. Radioisotopes taken internally for medical reasons ____.
a. must be eliminated from the body slowly
b. should be fissionable isotopes
c. are usually deposited in fat tissue
d. should have a short half-life