Download Unit 3 Study Guide: Atomic Structure and Nuclear

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Unit 3 Study Guide: Atomic Structure and Nuclear Energy
Section 4.1 Early Ideas About Matter
For each statement below, write true or false.
_______________ 1. Ancient philosophers regularly performed controlled experiments.
_______________ 2. Philosophers formulated explanations about the nature of matter based on their
own experiences.
_______________ 3. Both Democritus and Dalton suggested that matter is made up of atoms.
_______________ 4. Dalton's atomic theory stated that atoms separate, combine, or rearrange in
chemical reactions.
_______________ 5. Dalton's atomic theory stated that matter is mostly empty space.
_______________ 6. Dalton was correct in thinking that atoms could not be divided into smaller
particles.
_______________ 7. Dalton's atomic theory stated that atoms of different elements combine in simple
whole-number ratios to form compounds.
_______________ 8. Dalton thought that all atoms of a specific element have the same mass.
_______________ 9. Democritus proposed that atoms are held together by chemical bonds, but no
one believed him.
_______________ 10. Dalton's atomic theory was based on careful measurements and extensive
research.
Section 4.2 Defining the Atom
For each item in Column A, write the letter of the matching item in Column B.
Column A
Column B
a. Thomson
________ 1. Proposed the nuclear atomic model
________ 2. Determined the mass-to-charge ratio of an electron
b. Millikan
c. Rutherford
________ 3. Calculated the mass of an electron
Draw and label a diagram of each atomic model.
4. plum pudding model
5. nuclear atomic model
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Complete the following table of proton, electron, and neutron characteristics.
Particle
Symbol
Relative
Charge
Location
Relative
Mass
6. Proton
7.
n
8.
1/1840
Section 4.3 How Atoms Differ
For each statement below, write true or false.
_______________ 1. The number of neutrons in an atom is referred to as its atomic number.
_______________ 2. The periodic table is arranged by increasing atomic number.
_______________ 3. Atomic number is equal to the number of electrons in an atom.
_______________ 4. The number of protons in an atom identifies it as an atom of a particular
element.
_______________ 5. Most atoms have either a positive or a negative charge.
Answer the following questions.
6. Lead has an atomic number of 82. How many protons and electrons does lead have? ______________
7. Oxygen has 8 electrons. How many protons does oxygen have? ____________________
8. Zinc has 30 protons. What is its atomic number? ____________________
9. Astatine has 85 protons. What is its atomic number? ____________________
10. Rutherfordium has an atomic number of 104. How many protons and electrons does it have?
11. Polonium has an atomic number of 84. How many protons and electrons does it have?
12. Nobelium has an atomic number of 102. How many protons and electrons does it have?
Determine the number of protons, electrons, and neutrons for each isotope described below.
13. An isotope has atomic number 19 and mass number 39.
14. An isotope has 14 electrons and a mass number of 28.
15. An isotope has 21 neutrons and a mass number of 40.
16. An isotope has an atomic number 51 and a mass number 123.
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Answer the following question.
17. Which of the isotopes in problems 13-16 are isotopes of the same element? Identify the element.
Write each isotope below in symbolic notation. Use the periodic table to determine the atomic number of
each isotope.
18. neon-22 __________
19. helium __________
20. cesium-133 __________
21. uranium-234 __________
Label the mass number and the atomic number on the following isotope notation.
Circle the letter of the choice that best completes the statement.
25. The mass of an electron is
a. smaller than the mass of a proton.
b. smaller than the mass of a neutron.
c. a tiny fraction of the mass of an atom.
d. all of the above.
26. One atomic mass unit is
a. 1/12 the mass of a carbon-12 atom.
b. 1/16 the mass of an oxygen-16 atom.
c. exactly the mass of one proton.
d. approximately the mass of one proton plus one neutron.
27. The atomic mass of an atom is usually not a whole number because it accounts for
a. only the relative abundance of the atom's isotopes.
b. only the mass of each of the atom's isotopes.
c. the mass of the atom's electrons.
d. both the relative abundance and the mass of each of the atom's isotopes.
Use the figures to answer the following questions.
27. What is the atomic number of osmium? _______________
28. What is the chemical symbol for niobium? _______________
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29. What is the atomic mass of osmium? _______________
30. What units is the atomic mass reported in? _______________
31. How many protons and electrons does an osmium atom have? A niobium atom?
Calculate the atomic mass of each element described below. Then use the periodic table to identify each
element.
Mass
(amu)
Percent
abundance
63
62.930
69.17
65
64.928
30.83
Isotope
X
X
Mass
(amu)
Percent
abundance
35
34.969
75.77
37
36.966
24.23
Isotope
X
X
Section 4.4 Unstable Nuclei and Radioactive Decay
For each item in Column A, write the letter of the matching item in Column B.
Column A
Column B
________ 1. The rays and particles that are emitted by a radioactive material
a. nuclear reaction
________ 2. A reaction that involves a change in an atom's nucleus
b. beta radiation
________ 3. The process in which an unstable nucleus loses energy
spontaneously
c. radiation
d. radioactive decay
________ 4. Fast-moving electrons
Use the diagram to answer the questions.
5. Which plate do the beta particles bend toward? Explain.
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6. Explain why the gamma rays do not bend.
7. Explain why the path of the beta particles bends more than the path of the alpha particles.
Complete the following table of the characteristics of alpha, beta, and gamma radiation.
Radiation
Type
Composition
Symbol
Mass
(amu)
Charge
8. Alpha
9.
1/1840
10.
High-energy electromagnetic radiation
Section 24.1 Nuclear Radiation
Use each of the terms below just once to complete the passage.
alpha particle
radioactivity
gamma ray
radioisotope
beta particles
radiation
X ray
radioactive decay
The discovery of the (1) ____________________ in 1895 by Wilhelm Roentgen opened a whole new field of
research. Among those who worked in this new field were Pierre and Marie Curie. The Curies discovered that
some forms of matter give off (2) ____________________, a combination of particles and energy. Marie Curie
named this process (3) ____________________. Another term used to describe the process by which one
element spontaneously changes into another element is (4)____________________. Any isotope that undergoes
such changes is called a(n) (5) ____________________.
There are three common forms of radiation. One type is a form of energy known as (6)____________________.
The other types of radiation consist of particles. The form of radiation containing the heavier particle is made up of
helium nuclei called (7) ____________________. The form of radiation containing the lighter particle consists of
electrons called (8) ____________________.
Complete each statement.
9. Wilhelm Roentgen discovered the form of energy known as ____________________.
10. The form of nuclear radiation that has the greatest penetrating power is the ________________.
11. When a radioactive nucleus gives off a gamma ray, its atomic number increases by________________.
12. The three types of radiation were first identified by ____________________.
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13. Each alpha particle carries an electric charge of ____________________.
14. Each beta particle carries an electric charge of ____________________.
15. Each gamma ray carries an electric charge of ____________________.
Section 24.2 Radioactive Decay
Circle the letter of the choice that best completes the statement.
1. The number of stable isotopes that exist compared to the number of unstable isotopes is
a. much less.
b. much more.
c. slightly more.
d. about the same.
2. A lightweight isotope is likely to be stable if the ratio of protons to neutrons in its nucleus is
a. 1:2.
b. 1:1.
c. 2:1.
d. 5:1.
c. beta particle.
d. neutron.
3. The only nucleon among the following is the
a. electron.
b. positron.
4. The isotope least likely to be found in the band of stability among the following is
a.
b.
5. The isotope formed by the beta decay of
a. 18.
b. 39.
6. The isotope formed by the alpha decay of
a. 234.
b. 236.
c.
d.
has an atomic number of
c. 20.
d. 21.
has a mass number of
c. 238.
d. 240.
7. The positron produced during positron emission comes from a(n)
a. neutron.
b. proton.
c. electron.
d. positron.
8. During electron capture, a proton in the nucleus of an atom is converted into a(n)
a. neutron.
9. When the isotope
a.
b. positron.
c. electron.
decays by beta emission, the isotope formed is
b.
b.
d.
c.
10. The isotope formed by the alpha decay of
a.
d. another proton.
is
d.
c.
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11. The neutron-to-proton ratio for the isotope sodium-23 is
a. 1 : 1.1.
12. The decay of
a.
b. 1.1 : 1.
yields
c. 2.1 : 1.
d. 1 : 2.1.
c. γ.
d. e+ .
and
b. e- .
13. Atoms located above the band of stability on a graph of numbers of neutrons versus number of protons
are usually unstable because they contain too many
a. protons.
b. neutrons.
c. electrons.
d. nucleons.
Section 24.3 Nuclear Reactions
For each statement below, write true or false.
_______________ 1. Transmutation is the conversion of an atom of one element to an atom of
another element.
_______________ 2. All nuclear reactions involve some type of nuclear transmutation.
_______________ 3. Scientists induce transmutations by bombarding stable nuclei with high-energy
alpha, beta, or gamma radiation.
_______________ 4. The first induced nuclear transmutation was carried out by Marie and Pierre
Curie in 1897.
_______________ 5. Most induced transmutation reactions are produced in high-energy particle
accelerators.
_______________ 6. Neptunium and plutonium were the first transuranium elements discovered.
_______________ 7. The nuclear formula for a neutron is n.
_______________ 8. The half-life of a radioisotope is the time it takes for that isotope to decay.
_______________ 9. A radioisotope that decays very rapidly has a short half-life.
_______________ 10. Radioisotopes with very long half-lives are seldom found in Earth's crust.
_______________ 11. Temperature is the only factor that affects the half-life of a radioisotope.
_______________ 12. Carbon dating is not used to measure the age of rocks because the half-life of
carbon-14 is too short.
_______________ 13. After an organism dies, its ratio of carbon-14 to carbon-12 and carbon-13
increases.
_______________ 14. Scientists currently believe that all of the possible transuranium elements have
been discovered.
_______________ 15. When an atom of
and neutrons.
is bombarded with protons, the products are
_______________ 16. Mass number and atomic number are conserved in all nuclear reactions.
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_______________ 17. The mass of a 25.0 g piece of
after 7.2 hr.
(half-life: 2.4 hr) will be reduced to 3.1 g
Use the following diagram to complete the passage.
In a nuclear power plant, energy is produced in the reactor core by fission reactions that occur inuraniumcontaining bars called (18) ____________________. The uranium is found at location (19)_________________
in the diagram. The rate at which the nuclear reaction takes place is controlled by other bars called (20)
____________________. These bars of metal are found at location (21) ____________________. One of the
important safety factors in the power plant is a strong dome-shaped structure surrounding the reactor. The
structure is labeled (22) ____________________ in this diagram and called (23) ____________________.
Heat produced by nuclear fission is carried away by (24) ____________________, which enters the core at point
(25) ____________________ in the diagram. It then leaves the core at point (26) ____________________. Heat
from the reactor core is used to boil water in the (27) ____________________, shown at (28)________________
in the diagram. Steam produced here is used to generate electricity at point (29) ____________________ in the
diagram. The steam is then cooled at location (30)____________________ by water from an outside source.
For each statement, write true or false.
_______________ 31. A nuclear reactor produces energy from fuel rods containing uranium-238.
_______________ 32. The amount of energy produced for each kilogram of uranium is about the
same as the amount of energy from a kilogram of coal.
_______________ 33. The only elements that can be used as fuel in a nuclear power plant are those in
which a chain reaction can occur.
_______________ 34. If more than a critical mass is present in a sample, that sample is said to have
supercritical mass.
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_______________ 35. Water is the most common coolant used in a nuclear reactor.
_______________ 36. Nuclear power plants usually produce electricity.
_______________ 37. The purpose of the control rods in a nuclear reactor is to reflect neutrons back
into the core.
_______________ 38. The production of energy in a nuclear reactor can be stopped by pulling out all
control rods.
_______________ 39. A breeder reactor produces more fuel than it uses.
_______________ 40. The fission products produced in nuclear power plants are not radioactive.
_______________ 41. An uncontrolled chain reaction led to the nuclear accident in Chernobyl,
Ukraine.
Section 24.4 Applications and Effects of Nuclear Reactions
For each item in Column A, write the letter of the matching item in Column B.
Column A
Column B
______
1. Worn by workers to monitor radiation exposure
a. PET
______
2. Contains phosphors that detect radiation
b. Geiger counter
______
3. Radiation energetic enough to break apart atoms
c. 100-300 mrem
______
4. Uses a gas-filled metal tube to detect and measure radiation
d. ionizing radiation
______
5. A material that gives off light when struck by radiation
e. rad
______
6. A method used to detect very small amounts of an element in a
sample
f.
______
7. A radioisotope used to indicate the presence of an element in a
sample
h. genetic damage
______
8. Used to detect disorders of the thyroid gland
i.
neutron activation
analysis
______
9. A procedure that uses positrons to detect many different
medical disorders
j.
scintillation counter
10. This type of radiation easily penetrates human tissue.
k. radiotracer
11. Damage caused by radiation that affects a person, but not their
offspring
l.
iodine-131
g. rem
______
______
gamma ray
m. somatic damage
______
______
______
______
12. Radiation damage that can affect chromosomes and offspring
n. phosphor
13. A unit used to measure the amount of radiation absorbed by a
body
14. A unit used to measure the amount of damage done to a body
15. The annual amount of radiation to which a person is normally
exposed
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o. TLD badge
Reviewing Vocabulary
Match the definition in Column A with the term in Column B.
Column A
Column B
______
1. The difference between the mass of a nucleus and the sum of
its nucleons
a. strong nuclear force
______
2. The process in which an atom of one element changes into
an atom of another element
c. nucleon
______
3. A force that acts only on subatomic particles that are
extremely close together
d. radioactive decay
series
______
4. A fusion reaction that takes place only at very high
temperatures
e. induced transmutation
______
5. Isotopes of atoms with unstable nuclei that emit radiation
______
6. The area on a graph plotting neutrons and protons within
which all stable nuclei are found
______
7. Radiation energetic enough to ionize matter with which it
collides
______
8. The artificial production of a nuclear reaction that involves
striking the nuclei with high-velocity charged particles
______
9. A way of determining the age of very old objects using
radioactive materials
b. band of stability
f.
______
thermonuclear reaction
g. critical mass
10. A form of high-energy electromagnetic radiation
h. electron capture
i.
mass defect
j.
breeder reactor
k. transuranium element
l.
ionizing radiation
m. transmutation
n. radiochemical dating
11. A term to describe a sample of fissionable material that is
massive enough to sustain a chain reaction
o. radiotracer
12. Another name for a proton or neutron
p. radioisotope
13. A radioisotope that emits non-ionizing radiation and is used to
signal the presence of an element or specific substance
q. X rays
______
______
14. A series of nuclear reactions beginning with an unstable
nucleus and resulting in the formation of a stable nucleus
______
______
______
______
15. Any element with an atomic number greater than 92
16. A transmutation process brought about when an electron is
absorbed by a nucleus
17. Reactors able to produce more fuel than they use
______
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Understanding Main Ideas
Circle the letter of the choice that best completes the statement or answers the question.
1. The person who named radioactivity as the process in which materials give off rays and particles is
a. Marie Curie.
b. Henri Becquerel.
c. Wilhelm Roentgen. d. Ernest Rutherford.
2. The most penetrating form of nuclear radiation is
a. alpha rays.
b. beta rays.
c. gamma rays.
d. positrons.
3. In an atom, the strong nuclear force acts on
a. protons only.
b. neutrons only.
c. protons and neutrons.
d. protons, neutrons, and electrons.
4. During the process of electron capture, an electron from outside the nucleus joins with a proton to form
a. a neutron.
b. a positron.
c. another proton.
d. a gamma ray.
5. The half-life of calcium-47 is about 5 days. Starting with 64 g of this isotope, what would be the amount
remaining after 20 days?
a. 32 g
b. 16 g
c. 8 g
d. 4 g
c. electrons.
d. neutrons.
6. One product of all nuclear fission reactions is
a. protons.
b. a larger nucleus.
7. Mass is lost or gained in
a. all chemical reactions.
b. all nuclear fission reactions.
c. all nuclear fusion reactions.
d. all chemical and nuclear reactions.
8. A chain reaction will NOT take place in a piece of uranium if
a. the temperature is too low.
b. there are too many neutrons.
c. there are too few neutrons.
d. the piece of uranium is too large.
9. One of the most serious problems surrounding the use of nuclear power plants is
a. finding a way to dispose of spent fuel rods. c. a lack of uranium.
b. the high cost of coolant needed.
d. initiating a chain reaction in the fuel.
10. Fusion reactions require
a. very heavy nuclei.
b. incredibly high temperatures.
c. very rare elements for use as fuel.
d. no initial energy.
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Answer the following questions.
1. Listed below are six radioisotopes and the isotopes into which they decay. Tell what kind of radioactive
decay takes place in each case.
2. The five equations below represent nuclear fission and nuclear fusion reactions. For each equation, tell
whether fission or fusion has occurred and write the missing term in the equation.
3. Manganese-55 is bombarded with alpha particles. The nuclear equation for one possible transmutation
reaction is shown below. Complete the other four possible transmutation reactions, given one of the
reaction products.
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Thinking Critically
The graph below shows the trends in mass defect per nucleon for isotopes across the periodic table. The
vertical axis shows the relative stability of an isotope on a scale from 1 to 10, 10 being the most stable.
Answer the questions below about this graph.
1. What is the least stable of the isotopes shown on the graph? ___________________
2. What is the most stable of the isotopes shown on the graph? ___________________
3. What is the relative stability of an isotope of mass number 20?
4. Based on this graph, where are the least stable isotopes likely to be found in the periodic table?
5. Explain why isotopes near the beginning of the periodic table become more stable when they undergo
nuclear fusion.
6. Explain why isotopes near the end of the periodic table become more stable when they undergo nuclear
fission.
Applying Scientific Methods
The table below shows the results of an analysis done on a recently discovered rock. Answer the
following questions about the data in the table.
Radioisotope
Decay
Scheme
Predicted Order
of Abundance
Half-life
Thorium-232
Alpha emission 1.4 × 1010 years
Radium-228
Beta emission
6.7 years
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Actinium-228
Beta emission
6 hours
Thorium-228
Alpha emission 1.9 years
Radium-224
Alpha emission 3.6 days
1. Write a nuclear equation for the decay process each radioisotope in the table undergoes.
2. In column 4 of the table, indicate the order of abundance of the radioisotopes. Mark the most abundant
isotope 1, the second most abundant isotope 2, and so on.
3. Explain how you made the decision in question 2.
A cloud chamber is a detection device in which a
condensation track is formed when ionizing
radiation passes through a saturated vapor. The
diagram is a representation of a view seen in a
cloud chamber. In this diagram, various forms of
radiation are given off by a radioactive source (X
in the diagram). The upper electric plate is
positively charged (+) and the lower electric plate
is negatively charged (−). In the spaces
provided, identify the four types of radiation
shown in this diagram and tell how you decided
on each answer.
4. Radiation A is ____________________ because
5. Radiation B is ____________________ because
6. Radiation C is ____________________ because
7. Radiation D is ____________________ because
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