CHM1 Review for Exam 8 The following are topics and sample

Review for Exam 8
The following are topics and sample questions for the first exam.
1. Subatomic particles
a. Alpha, О±
b. Beta, ОІв€’
c. Positron, ОІ+
d. gamma, Оі
e. neutron, n
f. proton, p
1p or 1H
Penetraing ability О± < ОІв€’ = ОІ+ < Оі
2. Nuclear Reactions
a. Balancing nuclear reactions
b. Types of nuclear decay (transmutations)
i. Natural
1. Alpha
2. Beta
3. Gamma
4. Positron
5. Electron capture
ii. Induced (artificial) decay
3. Half-life - the amount of time required for half of a radioisotope to decay.
a. Fraction remaining = (1/2)N
b. N = t/T1/2 where N is the number of half-lives, t is the total amount of time
and T1/2 is the half-life of the isotope
4. Nuclear Energy
a. Nuclear Weapons
i. Gun type (Little Boy)
ii. Implosion type (Fat Man)
b. Nuclear reactors and power plant design
i. Fuel rods
ii. Control rods
iii. Moderators
iv. Cooling water
v. Turbine
vi. Containment and Shielding
c. Nuclear waste and disposal
Review for Exam 8
5. Multiple Choice (2 pts each)
Which subatomic particle has no charge?
(1) alpha particle
(2) beta particle
Which radioisotope is a beta emitter?
(1) 90Sr
(2) 220Fr
(3) 37K
(4) 238U
According to Table N, which radioactive isotope is best for determining the actual
age of Earth?
(1) 238U
(2) 90Sr
(3) neutron
(4) electron
(3) 60Co
(4) 14C
Which statement explains why nuclear waste materials may pose a problem?
(1) They frequently have short half-lives and remain radioactive for brief periods of
(2) They frequently have short half-lives and remain radioactive for extended
periods of time.
(3) They frequently have long half-lives and remain radioactive for brief periods of
(4) They frequently have long half-lives and remain radioactive for extended periods
of time.
Which type of radioactive emission has a positive charge and weak penetrating
(1) alpha particle
(2) beta particle
(3) gamma ray
(4) neutron
6. Which of these types of nuclear radiation has the greatest penetrating power?
(1) alpha
(2) beta
(3) neutron
(4) gamma
In the reaction 23993Np пѓ 23994Pu + X, what does X represent
(1) a neutron
(2) a proton
(3) an alpha particle
(4) a beta particle
Review for Exam 8
Which isotope is most commonly used in the radioactive dating of the remains of
organic materials?
(1) 14C
(2) 16N
(3) 32P
(4) 37K
9. Alpha particles and beta particles differ in
(1) mass, only
(2) charge, only
(3) both mass and charge
(4) neither mass nor charge
10. Given the nuclear reaction:
Co пѓ 0-1e + 6028Ni
This reaction is an example of
(1) fission
(2) fusion
(3) artificial transmutation
(4) natural transmutation
Which product of nuclear decay has mass but no charge?
(1) alpha particles
(2) neutrons
(3) gamma rays
(4) positrons
The change that is undergone by an atom of an element made radioactive by
bombardment with high energy protons is called
(1) natural transmutation
(2) artificial transmutation
(3) natural decay
(4) radioactive decay
As a sample of the radioactive isotope 131I decays, its half-life
(1) decreases
(2) increases
(3) remains the same
14. Nuclear fusion differs from nuclear fission because nuclear fusion reactions
(1) form heavier isotopes from lighter isotopes
Review for Exam 8
(2) form lighter isotopes from heavier isotopes
(3) convert mass to energy
(4) convert energy to mass
Which type of radiation has neither mass nor charge?
(1) gamma
(2) neutron
(3) alpha
(4) beta
Which list of particles is in order of increasing mass?
(1) proton --> electron --> alpha particle
(2) proton --> alpha particle --> electron
(3) electron --> proton --> alpha particle
(4) alpha particle --> electron --> proton
17. After 32 days, 5 milligrams of an 80 milligram sample of a radioactive isotope
remains unchanged. What is the half-life of this element?
(1) 8 days
(2) 2 days
(3) 16 days
(4) 4 days
18. Which process converts an atom from one element to another, when the nucleus of an
atom is bombarded with high-energy particles?
(1) artificial transmutation
(2) natural transmutation
(3) addition polymerization
(4) condenstation polymerization
19. A fission reaction is similar to a fusion reaction in that both reactions involve
(1) collisions between nuclei of high atomic number
(2) collisions between nuclei of low atomic number
(3) the conversion of mass to energy
(4) the conversion of energy to mass
20. The half-life of a radioactive substance is 2.5 minutes. What fraction of the original
radioactive substance remains after 10 minutes?
(1) 1/2 (3) 1/4
(2) 1/8 (4) 1/16
Review for Exam 8
21. Given the equation:
N + 42He --> X + 178O
When the equation is balanced correctly, which particle is represented by X?
(1) 0-1e
(2) 11H
(3) 21H
(4) 10n
22. When cobalt-60 undergoes nuclear decay, it emits
(1) a positron
(2) a neutron
(3) a beta particle
(4) an alpha particle
23. Which equation represents a fusion reaction?
(1) 21H + 21H --> 42He
(2) 146C --> 0-1e + 147N
(3) 23892U + 42He --> 24194Pu + 10n
(4) 10n + 2713Al --> 2411Na + 42He
24. A fusion reaction is similar to a fission reaction in that both reactions involve
(1) collisions between nuclei of high atomic number
(2) collisions between nuclei of low atomic number
(3) the conversion of mass to energy
(4) the conversion of energy to mass
Review for Exam 8
Short Answer
Base your answers to the following questions on the information below.
Radioactivity at home
You may be surprised to learn that you do not need to visit a nuclear power plant
or a hospital X-ray laboratory to find sources of radioactivity. They are all around us.
In fact, it is likely that you’ll find a few at home. Your front porch may incorporate
cinder blocks or granite blocks. Both contain uranium. Walk through the front door,
look up, and you’ll see a smoke detector that owes its effectiveness to the constant
source of alpha particle emissions from Americium-241. As long as the gases remain
ionized within the shielded container, electricity flows, and all is calm. When smoke
enters the chamber, it neutralizes the charges on these ions. In the absence of these
ions, the circuit breaks and the alarm goes off.
Indicator lights on your appliances may use Kryton-85; electric blankets,
promethium-147; and fluorescent lights, thorium-229. Even the food we eat is
radioactive. The more potassium-rich the food source, the more potassium-40 – a
radioactive isotope that makes up about 0.01% of the natural supply of this mineral –
is present. Thus, brazil nuts, peanuts, bananas, potatoes, and flour, all rich in
potassium, are radiation sources.
--Chem Matters
April 2000
25. (2 pts) Write the equation for the alpha decay that occurs in a smoke detector
containing Americium-241 (Am-241).
26. (2 pts) How is the radioactive decay of Krypton-85 different from the radioactive
decay of Americium-241?
27. (2pts) State one benefit or useful application of radioactivity not mentioned in
this article.
28. (2 pts) State one risk or danger associated with radioactivity.
Review for Exam 8
In the 1920s, paint used to inscribe the numbers on watch dials
was composed of a luminescent (glow-in-the-dark) mixture. The
powdered-paint base was a mixture of radium salts and zinc
sulfide. As the paint was mixed, the powered base became
airborne and drifted throughout the workroom causing the contents
of the workroom, including the painters’ clothes and bodies, to
glow in the dark.
The paint is luminescent because radiation from the radium
salts strikes a scintillator. A scintillator is a material that emits
visible light in response to ionizing radiation. In watch-dial paint,
zinc sulfide acts as the scintillator.
Radium present in the radium salts decomposes spontaneously,
emitting alpha particles. These particles can cause damage to the
body when they enter human tissue. Alpha particles are especially
harmful to the blood, liver, lungs, and spleen because they can alter
genetic information in the cells. Radium can be deposited in the
bones because it substitutes for calcium.
29. (2 pts) Write the notation for the alpha particles emitted by radium in the radium
30. (2 pts) How can particles emitted from radioactive nuclei damage human tissue?
31. (2 pts) Why does radium substitute for calcium in bones?
32. (2 pts) Explain why zinc sulfide is used in luminescent paint.
33. (2 pts) What is the formula for zinc sulfide?
Matching (2 pts each)
34. Enter the appropriate number in the blank.
___ Alpha particle
1. 42He
___ Beta particle
2. 21H
___ positron
3. 0-1e
___ neutron
4. 10n
___ deuterium
5. ОІ+
Review for Exam 8
Balancing (2 pts each)
What is the missing particle?
35. YZX пѓ 23490Th + 42He
36. 146C пѓ YZX + 0-1e
37. 21H + YZX пѓ 42He + 10n
38. 23592U пѓ 42He + YZX
39. 167N пѓ 0-1e + YZX
True/Correct the False (2 pts each)
40. A nuclear weapon based on a fusion reaction is more powerful than a fission
weapon. _____
41. A gamma particle is a high energy photon. ___
42. A beta particle and a positron have the same charge. ____
43. If a 1.0 g sample of a radioisotope has a half-life of 10 years, there will be 0.5 g of
the radioisotope after 20 years. ___
44. An alpha particle is positively charged. ___
Name the following ions
45. CO3246. SO4247. NO348. NH4+
49. Cl-
Review for Exam 8
1. 3
2. 1, See Reference Table N which will be provided on the test.
3. 1, it has the longest half-life
4. 4
5. 1
6. 4
7. 4
8. 1
9. 3
10. 4
11. 2
12. 2
13. 3
14. 1 (3 is true for both and the question how they differ)
15. 1
16. 3
17. 1
18. 1
19. 3
20. 4
21. 2
22. 3
23. 1
24. 3
25. 24195Am пѓ 42He + 23793Np
26. 85Kr is a beta emitter, not an alpha emitter like 241Am.
27. Medical imaging.
28. May cause cancer.
29. 42He
30. Ionizing radiation can break chemical bonds. Ionization can either be the adding
or removing of an electron from an atom or molecule to form a charge species. If
this cause a bond to be broken in a molecule such as DNA, it can cause mutations.
31. Ra is in group 2, and therfore has similar chemistry to Ca since it forms a 2+ ion.
32. It acts as a scintilator. When hit with a particle it cause an electron to be excited
to a higher energy level. When the electron falls back to a lower level it give off
33. ZnS
34. 1, 3, 5, 4, 2
35. 23992U
36. 147N
37. 31H
38. 23190Th
39. 168O
40. T
41. T
42. F, …have opposite charges.
43. F, …after 10 years.
44. T
45. Carbonate
46. Sulfate
47. Nitrate
48. Ammonium ion
49. Chloride
Review for Exam 8