Download Molecules/Formula Units to Atoms

Chemistry Unit 3: Atoms and Nuclear Chemistry
Chapter 3: Pages 74-91*
Chapter 21: Pages 649-671*
Learning Targets
Name ________________________
Block _________
Score: 5
4
3
Learning
Target
Assessment
Test #1
2
1
Test #2
Compare and contrast subatomic
particles.
Explain and determine the atomic
number and atomic mass of
elements, and molar mass of
compounds.
Understand the concept of isotopes
and how the mass number and
relative atomic mass are calculated.
Calculate molar conversion
problems.
Identify, describe, and write the
nuclear equations for alpha, beta,
gamma, and neutron decay.
Compare fission and fusion reactions
and applications of each.
Calculate half-life of a radioactive
isotope.
Please note – Learning Target Assessments (LTAs) cannot be retaken. Test #1 is worth 25 points and Test
#2 is worth 15 points. Test #3 will be worth 10 points and with completion of this learning packet the
opportunity to replace Test #1 score with the sum of Test #2 and Test #3 is available. You are strongly
encouraged to monitor your level of understanding for the learning targets using the table above.
*Modern Chemistry – Sarquis.Sarquis; Houghton, Mifflin, Harcourt (2017)
Date
My homework
Date
My homework
1
Questions adapted from: Sarquis, M, Sarquis, J.L. (2017). Modern Chemistry Orlando, Florida: Houghton,
Mifflin, Harcourt
LT 1: I can compare and contrast subatomic particles.
**Isotope Lab
LEVEL 1 PRACTICE: Questions and Problems
1. What is an atom? What does the term “atom” literally mean?
2. Describe the 2 regions that make up an atom?
3.
Subatomic
Particle
(symbol)
Location
Size
Charge
Proton (p+)
Electron (e-)
Neutron (no)
LEVEL 2 PRACTICE:
1. Nuclear forces are said to hold protons and neutrons together. What is it about the composition of the nucleus
that requires the concept of nuclear forces?
Check for Understanding:
1. What two common types of particles are located in the nucleus of the atom? What are the relative
charges of these particles? What are the relative masses of these particles?
2. Where is most of the mass of an atom located and why?
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LT 2: I can explain and determine the atomic number and atomic mass of elements, and molar mass of
compounds.
LEVEL 1 PRACTICE: Questions and Problems
1.
What is the atomic number? Can it be located on the periodic table, if so where?
2. What is mass number? Can it be located on the periodic table, if so where?
3. Label the components of the following atomic symbols:
Ca-40
Calcium – 40
𝟒𝟐
𝐂𝐚
𝟐𝟎
4. The number of protons in one atom of an element determines the atom’s _________________, and the number of
electrons determines the ___________________of an element.
5.
The atomic number tells you the number of ______________________in one atom of an element. It also tells you
the number of ___________________in a neutral atom of that element.
6. In order to calculate the number of neutrons you must subtract the __________________from the
______________________.
7. Give the symbol and number of protons in one atom of:
a. Lithium
b. Iron
c. Oxygen
__________
__________
__________
d. Krypton
e. Helium
__________
__________
8. Give the symbol and number of protons and electrons in a neutral atom of:
Uranium
______ Protons_______
Electrons_______ Boron ______
Protons_______ Electrons_______
9. Name the element that has the following numbers of subatomic particles:
a. 26 electrons, 29 neutrons, 26 protons ________
c. 53 protons, 74 neutrons ________
b. 2 electrons (neutral atom) ________
d. 20 protons _________
e. 15 protons _________
10. If you know only the following information can you always determine what the element is? If the answer is 'No'
explain why not.
a. number of protons
b. number of electrons in a neutral atom
c. number of neutrons
d. number of electrons
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11. What are isotopes? Describe an example.
12. Identify the following pairs of elements as isotopes or different elements.
a. Element A has 42 protons and 50 neutrons Element B has 42 protons and 51 neutrons
_______________________
b. Element X has 54 protons and a mass number of 124 Element Z has 54 protons and a mass number of 130
______________________
c. Element C has 38 neutrons and an atomic number of 22 Element D has 38 neutrons and an atomic number
of 23
_______________________
15. Fill in the following missing parts in the charts below:
Symbol
O-16
F
I
p+
e-
Mass #
Atomic #
10
74
69
111
145
50
75
U
Symbol
no
Protons
Electrons
Mass Number
Atomic Number
Neutrons
28
42
Cl-36
-87
37
37
14
6
59
65
U-
234
7
9
33
13. Determine the molar mass of the following:
KClO4
g/mol
Pb(SO4)2
SnI4
g/mol
(NH4)3PO4
CBr4
g/mol
CO2
H2O
g/mol
C6H12O6
Ca(NO3)2
g/mol
42
g/mol
g/mol
g/mol
g/mol
14. Describe how molar mass is calculated.
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LEVEL 2 PRACTICE:
1. Fill in the missing parts to the chart below: (ions=charged atoms)
Atomic
Symbol
Mass Number
Protons
Number
Neutrons
Electrons
30
25
21
18
52 Cr 3+
25
19
133
80
55
54
Br 1-
Zinc-65
2. Can two atoms with the same mass number ever be isotopes of each other? Explain.
Check for Understanding:
1. Complete the following table.
Name
Nuclear Symbol
Sodium – 23
157N
Lithium - _____
Boron - 11
Protons
11
Neutrons
Electrons
8
6
5
2. There are three stable isotopes of Argon: Argon-36, Argon-38, and Argon-40. What would the atoms of
these isotopes have in common? What would be different about their atoms?
3. Calculate the Molar Mass of each of the following to TWO decimal places.
A. CuNO3
____________________________________
B. Ag2SO4
____________________________________
C. Ca3(PO3)2
____________________________________
D. H2O
____________________________________
LT 3: I understand the concept of isotopes and how the mass number and relative atomic mass are
calculated.
**POGIL – Average Atomic Mass (first 3 questions below taken from: POGIL Activities for High School Chemistry.
2012. The POGIL Project and Flinn Scientific, Inc.
LEVEL 1 PRACTICE: Questions and Problems
1. The average atomic mass of nitrogen is 14.0067amu. Predict which isotope listed below is most abundant in
nature?
a. N-13
b. N-14
c. N-15
2. Explain why a weighted average is used to calculate the average atomic mass of an element. Why is it not
sufficient to calculate a simple average of the isotope data?
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3. A mystery element, called ‘muriacticum’ by its discoverer, exists on Earth as a mixture of two isotopes. The
most abundant isotope (75.76%) has a mass of 34.9689amu; the other isotope (24.24%) has a mass of 36.9659
amu. Calculate the average atomic mass and identify the element by its modern name.
Example Calculations
4. Calculate the average atomic mass of Carbon.
12 C
13 C
6
Actual Mass
12.000000 amu
98.90% abundant
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Actual Mass
13.003355 amu
1.10% abundant
5. Determine the average atomic mass of the following: There are 4 isotopes of an unknown element. If out of 100
atoms, 28 have a mass of 171 amu, 45 have a mass of 172 amu, 12 have a mass of 174 amu and 15 have a mass of
178 amu.
6. Determine the percent of each isotope in the following: There are 2 stable isotopes of Warriorium. Warriorium258 and Warriorium-267 have an average atomic mass of 264.275 amu.
7. When a sample of natural copper is vaporized and injected into a mass spectrometer, the results show the
sample is 69.09% copper-63 and 30.91% copper-65. Use these data to compute the average mass of natural
copper. (The mass values for 63Cu and 65Cu are 62.93 amu and 64.93 amu, respectively.)
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8. What is the atomic mass of hafnium if, out of every 100 atoms, 25 have a mass of 176 amu, 16 have a mass of 177
amu, 23 have a mass of 178 amu, 31 have a mass of 179 amu, and 5 have a mass of 180 amu? **Hint: Think back to
Skittle Lab!
9. What is the atomic mass of lithium if 8.5% of its atoms have a mass of 6.02 amu and 91.5% of its atoms have a
mass of 7.02 amu?
10. Three isotopes of argon occur in nature -- calculate the average atomic mass of argon to two decimal places,
given the following relative atomic masses and abundances of each of the isotopes: argon-36 (35.97 amu; 0.337%),
argon-38 (37.96 amu; 0.063%), and argon-40 (39.96 amu; 99.600%).
LEVEL 2 PRACTICE:
1. Three isotopes of silicon occur in nature. 92.23% occur as Silicon-28 (which has an atomic mass of 27.97693
amu); 4.68% occur as silicon-29 (which has and atomic mass of 28.97649 amu); and 3.09% occur as silicon-30
(which has and atomic mass of 29.97377 amu). Calculate the atomic weight of silicon.
Check for Understanding:
1. What is the atomic mass of magnesium if 78.99% of its atoms have a mass of 23.98 amu, 11.01% of its atoms
have a mass of 24.98 amu, and 10.00% of its atoms have a mass of 25.98 amu? (1 point)
2. What is the atomic mass of hafnium if, our of every 100 atoms, 33 have a mass of 161 amu, 15 have a mass of
163 amu, 15 have a mass of 165 amu, 9 have a mass of 167 amu, and 28 have a mass of 169 amu? (1 point)
3. There are only two isotopes of Antimony: Antimony-121 and Antimony-123. Calculate the percentage of each
isotope if the average atomic mass of Antimony is 121.76 amu.
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LT 4: I can calculate molar conversion problems.
LEVEL 1 PRACTICE: Questions and Problems
1. Describe a mole (use, size, etc).
-MOLE MAP-
Moles and grams
2. 100 g of NaOH = ? moles of NaOH
3. 3.5 moles of CO2 = ? grams of CO2
4.
650 g of H2O = ? grams of H2O
Grams to moles = _______________ by molar mass
Moles to grams = _______________ by molar mass
Moles and molecules
5. 4.25 x 1027 molecules CO = ? moles of CO
6. 1.28 x 108 mol PbBr4 = ? molecules of PbB4
7. 1.2 x 1020 molecules SnO = ? moles SnO
Molecules to moles = _____________________ by 6.022 X 1023
Moles to molecules = ____________________ by 6.022 X 1023
Molecules/Formula Units to Atoms
8. 3.0 X 1015 molecules of C6H12O6 = ? atoms of C
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9. 9.03 X 1024 atoms of Br2 = ? molecules of Br2
10. 2.3 X 1025 formula units of NaCl = ? atoms (total atoms)
Atoms to Molecules/Formula Units = _____________________ by subscript of element(s)
Molecules/Formula Units to Atoms = _____________________ by subscript of element(s)
Mixed Questions
11. Convert the following:
36.03 g C ? atoms C
2.408 X 1024 formula units NaCl  ? g NaCl
.25 moles H2O ? g H2O
12.67 moles C6H12O6 ? molecules C6H12O6
1000 g Cl2  ? molecules Cl2
3.01 X 1025 atoms of Au  ? grams Au
4.2 X 1022 molecules of NO2  ? grams of NO2
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LEVEL 2 PRACTICE:
1. Juglone, a dye known for centuries, is produced from the husks of black walnuts. It is also a natural herbicide
that kills off competitive plants around the black walnut tree but does not affect grass and other noncompetitive
plants. The formula for juglone is C10H6O3.
(a.) Calculate the molar mass of juglone.
(b.) A sample of 1.56 x 10-2 g of pure juglone was extracted from black walnut husks. How many moles of
juglone does this sample represent?
2. Calcium carbonate, also called calcite, is the principle mineral found in limestone, marble, chalk, pearls, and the
shells of marine animals such as clams.
(a) Calculate the molar mass of calcium carbonate.
(b) A certain sample of calcium carbonate contains 4.86 moles. What is the mass in grams of this sample?
What is the mass of the CO32- ions present?
Check for Understanding:
1. What is the mass in grams of 2.52 mol of iron, Fe?
2. How many moles of calcium, Ca, are in 0.565 g of calcium?
3. How many molecules of H2O, water, are in 3.75 mol of water?
4. What is the mass in grams of 5.7 x 1015 atoms of sodium chloride, NaCl?
5. How many atoms of sulfur, S, are in 3.00 g of sulfur?
LT 5: I can identify, describe, and write the nuclear equations for alpha, beta, gamma, and neutron decay.
LEVEL 1 PRACTICE: Questions and Problems
1. What is a nuclear reaction? What determines the stability of the nuclide?
2. What is the neutron-proton ratio among elements with low atomic numbers? High atomic number?
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3. What is the difference between ionizing and non-ionizing radiation?
4. Define radioactive decay
5. Compare and contrast the three types of radiation.
Type of
Radiation
Alpha
Symbol
Change in Mass #
Change in Atomic #
Charge
Decreases by 4
Decreases by 2
2+
Beta
No Change
Increases by 1
1-
Gamma
No Change
No Change
0
6. Complete the following nuclear decay equations:
E.
2386Ra
 _______ + 42He
B.
8737Rb
 8738Sr + _______
F.
9943Tc
C.
263106Sg
 259104 Rf + ________
G.
137N
D.
116C
H.
10646Pd
 ______ + 0+1
146C
 ______ + 0-1
A.
 ______ + 
 136C + _______
+ ____  10645Rh
7. Predict the isotopes for the following:
A. Th-234
+1 beta particle
C. U-238
+ 1 alpha particle
B. Ba-141
+ 1 beta particle
D. Cs-136
+1 alpha particle
8. Show the breakdown of the following isotopes being hit by one neutron:
A. U-235 to Ba-142 and Kr-92
B. U-235 to Rb-90 and Cs-144
C. U-238 to Xe-142 and Sr-192
9. Write a nuclear equation for the alpha decay of palladium-231.
10. .Write a nuclear equation for the positron decay of nitrogen-13.
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11. Write a nuclear equation for the beta decay of francium-223.
12. Write a nuclear equation for the alpha decay of gadolinium-150.
13. Uranium-235 decays by the series below. What is the final stable element?
235 U  ,,,,,,,,,,  __________
92
Check for Understanding:
1. Show the breakdown of the following radioactive isotope being hit by one neutron.
U-238 + Neutron  Ba-141 and Kr-90
2. Predict the daughter species when the parent species undergoes alpha decay.
Np-238 
3. Predict the daughter species when the parent species undergoes beta decay.
Th-234 
4. Complete the continuing radioactive decay for the following radioactive isotope:
Alpha 
Beta
 Neutron
 Gamma
235
92 U  _____  _____  _____  _____
LT 6: I can compare fission and fusion reactions and applications of each.
LEVEL 1 PRACTICE: Questions and Problems
1.How are nuclear fusion and nuclear fission alike? How are they different? Which is used in nuclear bombs and
nuclear reactors? Why?
Check for Understanding:
1. Compare and contrast nuclear fission and fusion. Describe an example of each.
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LT 7: I can calculate half-life of a radioactive isotope.
Calculating Half-lives
A. Half-life (t1/2) = time required for half of the atoms of a radioactive nuclide to decay.
B. Solve half-live problems, first determine the rate constant (k)
k = ln(0.5)/half life years
C. Use the k value to determine how long it takes for decay to occur
t1/2 = ln(time left as decimal)/k
Example:
The radioactive isotope cobalt-60 has a half-life of 5.27 years. What is the rate constant?
K = ln(0.5)/5.27 = -0.132
How long will it take 20% of the cobalt-60 to change to nickel-60?
t1/2 = ln(.80)/-0.132 = 1.69 years
How long will it take 70% of the cobalt-60 to decay to nickel-60?
t1/2 = ln(.30)/-0.132 = 9.12 years
LEVEL 1 PRACTICE: Questions and Problems
The radioactive isotope carbon-14 has a half-life of 5730 years.
1. What is the rate constant for carbon-14?
2. How long will it take for 10% of the carbon-14 to change to nitrogen-14?
3. How long will it take for 50% of the carbon-14 to change to nitrogen-14?
4. How long will it take for 75% of the carbon-14 to change to nitrogen-14?
The radioactive isotope U-238 has a half-life of 4.5 billion years.
5. What is the rate constant for U-238?
6. How long will it take for 20% of the U-238 to change?
7. How long will it take for 65% of the U-238 to change?
8. How long will it take for 90% of the U-238 to change?
The radioactive isotope Pu-239 has a half-life of 24,400 years.
9. What is the rate constant for Pu-239?
10. How long will it take for 15% of the Pu-239 to change?
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11. How long will it take for 60% of the Pu-239 to change?
12. How long will it take for 95% of the Pu-239 to change?
Check for Understanding:
1. The radioactive isotope Uranium-238 has a half life of 4,500,000,000 years.
A). What is the rate constant for Uranium-238? (1 point)
B) How long will it take for 25% of the Uranium-238 to change to Thorium-234?
C) How long will it take for 65% of the Uranium-238 to change to Thorium-234?
D) How long will it take for 93.75% of the Uranium-238 to change to Thorium-234?
Review lab concepts.
Reflect:
What do I need to work on? What steps will I take to understand and apply the concepts better?
CCRS for this Unit:
Description
Secure (S)
Developing (D)
Beginning (B)
CCRS #1
How well do
you
productively
work towards
accomplishing
goals?
CCRS #2
How well do
you collaborate
with others?
Creates and monitors a
personal organization plan that
sets and prioritizes goals within
a timeframe.
Creates a personal
organization plan to
accomplish a task or meet
goals by using available
resources and meeting
deadlines.
Implements teacherdesigned organization
plan to accomplish a
task or goal.
Engages in interdependent
work with others to solve
problems through
communication, questioning,
and respectful discussion.
Engages in work with
others to solve problems
while working towards
developing habits of
questioning and respectful
discussion.
Participates in
independent work and
ask questions of others.
CCRS #3
How well do
you utilize
feedback for
improvement?
CCRS #4
How well do
you
demonstrate
respect?
Initiates communication with
others to seek and respond to
specific information for growth
toward a goal.
Responds to specific
information for growth
toward improving skills.
Responds to feedback as
a part of task
completion.
Initiates interactions with
others using language, body
language, listening skills, and
actions that contribute to a
positive learning community.
Understands and
acknowledges the impact of
using language, body
language, listening skills,
and actions that contribute
to a positive learning
community.
Recognizes the impact of
language, body
language, listening skills,
and action that
contribute to a positive
learning community.
Score
CCRS UNIT REFLECTION: Complete a reflection on your current score recorded for all 4 standards that includes examples of how
you have demonstrated or not demonstrated the standard. For all standards record a plan of action (POA) to work towards secure for
the standard. **Reflect on the different aspects of class: peer learning activities, class work time, lab time, at home learning, etc…
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