Honors
Atom
Name:
Period:
Goal: The learner will build an understanding of the structure and properties of matter. The learner will build an understanding of
energy changes in chemistry.
Objectives: Summarize the development of current atomic theory.
Examine the nature of atomic structure:
*protons
*Neutrons
*Atomic mass
*Isotopes
*Atomic number
*Electron configuration
*Energy levels
*Electrons
Analyze and explain the nature and behavior of the atomic nucleus.
Summarize the essential points of Dalton’s atomic theory.
Summarize the experiment carried out by Rutherford that led to the discovery of the nucleus.
Calculate the average atomic mass of a mixture of isotopes of an element.
Describe the wave mechanical view of the hydrogen atom.
Describe an electron cloud.
Characterize the four quantum numbers.
Use the Pauli’s exclusion principle and quantum numbers to describe an electron in at atom.
Determine the electron configuration of the elements.
Write electron dot diagrams for the elements.
Day 22 Wednesday September 25, 2013 Take KMT test
1. Cw/hw – complete marble activity
 Begin ChemThink – The particle theory (Your code is: 9547 – 2576 – 4782)
 Study for PT quiz #2
Day 23 Thursday 9/26/13 What is the early atomic theory?
1. PT quiz #2
2. Share marble activity data
3. Early atomic theory
4. cw/hw – Early History of the Atom wks 1
ChemThink (The Atom – all parts (atomic structure, ions, isotopes))
Day 24 Friday 9/27/13 Are isotopes and ions synonyms, antonyms, or neither? What are isotopes and ions?
1. Go over homework
2. parts of the atom (Atomic structure wks 2)
3. Bohr model of the atom
4. cw/hw -atomic structure wks 3
Bohr Model and Electromagnetic Spectrum Worksheet 4
Day 25 Monday 9/30/13 Describe the Bohr model of the atom.
1. Go over homework
2. Its Coinium (Lab B)
3. Isotopic penny (lab C)
4. Mass
5. cw/hw - Isotopes and average atomic mass (worksheet 5)
Day 26 Tuesday 10/1/13 How do you calculate an average atomic mass?
1. quick quiz #4 / History of the Atom Quiz
2. “New” atom
3. Electron configuration (level one) {class work 6 }
4. cw/hw – electron configuration worksheet 7
STUDY for the PT QUIZ (all required elements)
Day 27 Wednesday 10/2/13 What is the “new” atomic theory?
1.
2.
3.
4.
5.
Go over homework
Quantum Theory
Electron configuration (level two) {class work 8}
Electron configuration and Electron dot
→ valence electron (class work worksheet 9)
→ Lewis dot diagram (class work worksheet 10)
cw/hw - Electron configuration worksheet 11
STUDY for the PT QUIZ (all required elements)
Day 28 Thursday 10/3/13 What is the quantum theory of atoms?
1. Go over homework
2. Nuclear
3. cw/hw - Nuclear Chemistry worksheet 12
Make a study guide/complete a review sheet
Day 29 Friday 10/4/13 How can I demonstrate my knowledge of the atom?
1.
TEST
Early History of the Atom
worksheet 1
Answer the following questions on notebook paper. Provide complete answers for each
question. This will take from a sentence to a paragraph.
1. Compare and contrast the atomic theories proposed by Democritus and Dalton.
2. List/describe the postulates that formed Dalton’s Atomic Theory.
3. There have been several different models of the atom in the last hundred and fifty years.
Originally, atoms were thought to be indestructible spheres, followed in quick succession by
Thomson’s Plum Pudding model and Rutherford’s nuclear model. Sketch each of these models
and compare and contrast their view of the atom.
4. Thomson used a cathode ray tube to discover the electron. Sketch this apparatus and explain how
Thomson was able to deduce that the electron existed from the experimental results.
5. Explain why both Thomson and Rutherford’s experiments were unable to deduce the existence
of the neutron.
6. If atoms really conformed to the plum pudding model of the atom, what would the results of
Rutherford’s experiment have been? Explain your answer, using diagrams if necessary.
7. Make a table comparing the relative charge, mass, and location of each of the (major) subatomic
particles.
8. List the major subatomic particles and identify each scientist (discussed in class / text) and how
they contributed to our understanding of that particle.
Element /
Ion
H
H+
12 C
6
7 Li+
3
35 Cl17
39 K
19
24 Mg+2
12
As3Ag
Ag+
S2U
Atomic
Number
Average
Atomic
Mass
Mass
Number
Protons
Neutrons
Worksheet 2
Electrons Ion
and/or
Isotope
Worksheet 3
Name
Symbol
Boron – 11
Atomic
Mass
Atomic
Number
Mass
number
52
Sulfur – 32
101.1
40
Ca
# of
protons
2.
2.
3.
4.
5.
6.
n/a
(neither)
18
100
22
18
32
20
+2
isotope
+2
70
What numbers on the periodic table are needed to tell you the number of protons in any atom? Which number on
the periodic table corresponds to the number of electrons? the number of neutrons?
Which subatomic particle determines the element’s identity? Justify your choice .
Bohr Model & Electromagnetic Spectrum Practice
1.
# of
electrons
24
70
1.
# of
neutrons
Complete the following chart
ion/isotope
Charge
Worksheet 4
When an electron moves from energy level 3 to energy level 2 in the hydrogen atom it:
a. Releases energy and gives off light as it is excited
b. Absorbs energy and gives off light as it moves to ground state
c. Releases energy and gives off light as it moves to ground state
d. Absorbs energy and gives off light as it is excited.
Identify the type of energy given off and the wavelength in nanometers of the wave when each of the
following electron transitions occur.
Example: 4  1 = UV  97 nm
a. 6  2
c. 6  3
e. 3  2
b. 5  3
d. 3  1
f. 2  1
What color of light will be produced when each of the following electron transitions occur?
a. 3  2
b. 5  2
c. 4  2
d. 6  2
Which of the following waves has the highest frequenc y?
a. X-rays
b. Microwaves
c. Infrared
d. Radio waves
Which of the following waves has the highest energy?
a. Ultraviolet
b. Gamma Rays
c. Visible Light
d. Microwaves
Which of the following waves has the longest wavelength?
a. Ultraviolet
b. Gamma Rays
c. Visible Light
d. Microwaves
Coinium
Lab B
Problem
1. How can you determine the % abundance of each isotope in a sample of an element?
2. How can you determine the atomic mass for an element from % abundance?
Materials
baggie containing atoms (coins)
balance
Information:
Isotopes are atoms of an element which are chemically the same, but have different physical
properties. Isotopes differ in their atomic masses. Since atoms are very small we will substitute a larger
item, a coin, to represent the different isotopes of our element, coinium.
In this activity you will be using different types of coins. Each type of coin represents an isotope
of the new element coinium. Using the masses of your coins, find the average atomic mass of your element
coinium.
Procedure:
1. Determine the total number of each different type of isotope.
2. Find the average mass of each isotope. (pennies, nickels, dimes)
3. Determine the percent composition of each isotope in the sample. (i.e. what percent is
pennies/nickels/dimes?)
4. Using the method of weighted averages, determine the atomic mass of your element coinium. (atomic
mass = %isotop(1)*average mass of isotope(1) + %isotope(2)*average mass of isotope(2) +
%isotope(3)*average mass of isotope(3))
Summing Up:
1. How many different isotopes were in the container?
2. What was the total mass of each group of isotopes?
3. What is the atomic mass of each isotope?
4. What were the % abundances of each isotope in the entire sample?
5. What was the weighted average atomic mass of your sample?
6. A student obtained the following data when measuring a sample of element X.
Isotope
# of atoms
Mass of sample
A
40
400
B
160
1760
Determine the following:
a. percent composition of each isotope in the sample
b. average mass of each isotope
c. the atomic mass of element X
d. What is the name of element X?
Lab C
Isotopic Pennies
Question:
How many pre—1983 and post-1982 pennies are contained within the film canister?
Information:
According to Dalton’s atomic hypothesis, all atoms of the same element are identical. This notion of the
atoms, however, is somewhat outdated, as not all atoms of the same element possess the same number of
neutrons (possess a different atomic mass). It is in this spirit, a demonic form of torture, involving pennies,
has been selected for you.
Starting in 1983, pennies were no longer made of pure copper, as the cost of making a penny was becoming
prohibitive. Because of this, zinc, a much cheaper metal, was used in conjunction with copper to make a
penny. As a result, the newer pennies possess a different mass.
The task of this lab is to have you determine the number of pre-1983 and post-1982 pennies that are
contained within a film canister without opening it. In order to do this, a couple of assumptions will be
required. First, there are 15 pennies in each container. Second, the average mass of a pre—1983 penny is
3.11 grams and of a post-1982 is 2.5 grams. Since you will be unable to open the canisters, the mass of the
canister is provided for you on the canister in permanent ink. Use what you already know about how
average atomic mass was calculated for isotopes!
Summing Up:
1. Explain the process you used to determine the number of each type of penny. Include your calculations
in your explanation.
2. How does this lab relate to what has been discussed about isotopes?
Isotopes and Average Atomic Mass
Worksheet 5
Determine the average atomic mass of the following mixtures of isotopes.
1. 80% 127I, 17 126I, 3% 128I
2. 50%
197
Au, 50%
198
Au
197.5
3. 98% 12C, 2% 14C
4. 95% 14N, 3%
5. 15%
55
15
Fe, 85%
12.04
N, 2%
56
126.86
16
N
14.07
Fe
55.85
6. 99% 1H, 0.8% 2H, 0.2% 3H
1.012
Electron Configuration
worksheet 6
Write the electron configurations of the following atoms.
1. K
2. V
3. Co
4. Zr
5. Cu
Electron Configuration
Draw the orbital notation of the following atoms.
1. Cl
worksheet 7
2. N
3. Al
4. O
5. Ca
Electron Configuration
Draw the short hand electron configuration of the following atoms.
1. K
5. Cu
2. V
worksheet 8
8. Al
9. O
3. Co
6. Cl
10. Ca
4. Zr
7. N
Valence Electrons
worksheet 9
The valence electrons are the electrons in the outermost principle energy level. They are always “s” or “s and p”
electrons. Since the total number of electrons possible in s and p sublevels is eight, there can be no more than
eight valence electrons.
Determine the number of valence electrons in the atoms below.
Example: carbon
Electron configuration is 1s2 2s2 2p2
Carbon has 4 valence electrons
1. fluorine
______
11. Lithium
______
2. phosphorus______
12. zinc
______
3. Calcium
______
13. carbon
______
4. Nitrogen
______
14. iodine
______
5. Iron
______
15. oxygen
______
6. Argon
______
16. barium
______
7. Potassium ______
17. aluminum ______
8. Helium
18. hydrogen ______
______
9. Magnesium______
19. xenon
______
10. Sulfur
20. copper
______
______
Lewis Dot Diagrams
Worksheet 10
Lewis diagrams are a way to indicate the number of valence electrons around an atom.
Draw Lewis dot diagrams of the following atoms.
1. calcium
6. carbon
2. potassium
7. helium
3. argon
8. oxygen
4. aluminum
9. phosphorus
5. bromine
10. hydrogen
Electron Configurations
Worksheet 11
PART A – ORBITAL DIAGRAMS & LONGHAND ELECTRON CONFIGURATION
Use the patterns within the periodic table to draw orbital diagrams and write longhand electron
configurations for the following atoms.
Symbol
1.
# e-
Orbital Diagram and
Longhand Electron Configuration
Mg
2.
P
3.
V
4.
Ge
5.
Kr
6.
O
PART B – SHORTHAND ELECTRON CONFIGURATION
Use the patterns within the periodic table to write the shorthand electron configurations for the following elements.
Symbol
7.
Ca
8.
Pb
9.
F
10.
U
# e- Shorthand Electron Configuration
PART C – RULES OF ELECTRON CONFIGURATIONS
Which of the following “rules” is being violated in each electron configuration below? Explain your
answer for each. Hund’s Rule, Pauli Exclusion Principle, Aufbau Principle
11.
12.
13.
14.


 __ __
1s
2s
2p


  
___
 _ _
1s
2s
2p
3s
3p


  
1s
2s
2p


  
1s
2s
2p
   _
3s
3p
   
3s
3p
    
3d
The Modern Atom
worksheet 12
Featuring Quantum Mechanics!
1) Explain how the flame test results in different spectra for different elements.
2) Explain the basic idea behind spectroscopy.
3) Write the electron configurations (both the short and long versions) and the electron dotdiagrams for the following elements: K, Mg, Pu, Lr, Ga, Pb, Sb, S, Br, Ne
4) Write the orbital filling diagram for Ca.
Nuclear Chemistry Worksheet
worksheet 13
Using your knowledge of nuclear chemistry, write the equations for the following processes:
1)
The alpha decay of radon-198
2)
The beta decay of uranium-237
3)
Positron emission from silicon-26
4)
Sodium-22 undergoes electron capture
5)
What is the difference between nuclear fusion and nuclear fission?
6)
What is a “mass defect” and why is it important?
7)
Name three uses for nuclear reactions.
8)
An atom undergoes a reaction and reaches a more stable form. How do you know if the reaction
was chemical or nuclear?
9)
If Carbon – 14 has a half-life of 5730 years, how much of a 10.0mg sample is left after one halflive? two half-lives? three half-lives?
10)
After 5 half-lives 25.0mg of a Radon-222 sample remains, how much was present before it
began to decay?
11)
What is required to shield alpha, beta, and gamma particles?