Download Unit #3: ATOMIC STRUCTURE - Miss Virga`s Chemistry Class

Unit #3: ATOMIC STRUCTURE
IHS Regents Chemistry
Miss Virga
October 24 – November 7, 2016
Name:
Period: ________
Essential Questions for the Unit:
How has the view of the atom evolved over time?
What are the different parts of an atom?
How is an atom arranged?
Checkpoint Quizzes
Quiz #1: _____________
Testing
Your unit exam will be on
.
1
Unit #3: Atomic Structure
OVERVIEW
Topic 3.1: History of the Atom
Topic 3.2: Subatomic Particles & Symbols
Topic 3.3: Isotopes & Average Atomic Mass
Topic 3.4: Electron Configurations
Topic 3.5: Ground vs. Excited State
Topic 3.6: Bright Line Spectrum
Topic 3.7: Lewis Dot Diagrams
KEY TOPICS & VOCABULARY
 History of the atom
o Bohr Model
o Quantum Theory/Wave Mechanical Model (orbitals)
o Rutherford’s Gold Foil Experiment
 Subatomic particles and charges
o proton, neutron, electron
o positive, neutral, negative
o atomic mass unit
o mass number
o atomic number
o nuclear charge
 Isotopes
o average atomic mass
 Electron Configuration
o Lewis Dot Diagram
o valence electrons
o excited and ground states
o bright line spectrum
KEY SCIENTIFIC SKILLS





Modeling using diagrams
Modeling using formulas and equations
Mathematically manipulating equations
Interpreting tables and graphs
Stating relationships
REFERENCE TABLES
 Periodic Table
 Table S
2
CALENDAR – RED & GREEN CLASSES
MONDAY
TUESDAY
24
D
WEDNESDAY
25
E
Topic 3.1 History
of the Atom
HW: Assign. #1
THURSDAY
26
S
A
Topic 3.3 Isotopes &
Average Atomic Mass
Lab #9: M&Mium
HW: Assign. #2
HW: Assign. #3
HW: Assign. #3
Topic 3.2 Subatomic
Particles
C
27
POGIL 3.1 Atomic
Structure
31
D
2
E
Topic 3.6 Bright Line
Spectrum
Topic 3.7 Lewis Dot
Structures
HW: Assign. #4
Chemistry Work
Period
HW: Assign. #5
HW: Assign. #6
Lab #10: Flame Tests
HW: Assign. #1-7
8
C
Element Posters
Quiz 3.1
S
Topic 3.5 Ground vs
Excited State
B
B
3
Topic 3.4 Electron
Configurations
Unit 3 Test
28
Unit 2 Review/Chemistry
Work Period
1
7
FRIDAY
A
Review/Make Up
Day
Chemistry Work
Period
9
D
4
10
11
E
Checkpoint Test #1
NO SCHOOL
Checkpoint Test #1
3
CALENDAR – BLUE & ORANGE
MONDAY
TUESDAY
24
D
WEDNESDAY
25
E
Topic 3.1 History
of the Atom
HW: Assign. #1
THURSDAY
26
FRIDAY
27
S
A
Topic 3.2 Subatomic
Particles
Topic 3.3 Isotopes &
Average Atomic Mass
Unit 2 Review/Chemistry
Work Period
HW: Assign. #2
HW: Assign. #3
POGIL 3.1 Atomic
Structure
B
Lab #9: M&Mium
31
C
1
D
Topic 3.4 Electron
Configurations
Topic 3.5 Ground vs
Excited State
HW: Assign. #4
HW: Assign. #5 & 6
Topic 3.6 Bright Line
Spectrum
7
B
Unit 3 Test
Element Posters
Quiz 3.1
Chemistry Work
Period
2
E
3
S
Lab #10: Flame Tests
4
A
Topic 3.7 Lewis Dot
Structures
Review/Make Up
Day
HW: Assign. #1-7
Chemistry Work Period
8
C
28
9
D
10
11
E
Checkpoint Test #1
NO SCHOOL
Checkpoint Test #1
4
TOPIC
3.1
HISTORY OF THE ATOM
How has our view of the atom evolved over time?
DEMOCRITUS
JOHN DALTON
FATHER OF ATOMIC THEORY
J.J. THOMSON
PLUM PUDDING MODEL
5
ERNEST RUTHERFORD
Rutherford’s ___________________ Experiment
Experimental Result (Observation)
Explanation of Result (Conclusion)
6
BOHR MODEL/PLANETARY MODEL
NIELS BOHR
SCHRODINGER
WAVE-MECHANICAL/CLOUD MODEL
7
ASSIGN.
#1
Development of the Atom
Regents Practice
1.) An orbital of an atom is defined as the most probable location of
(1) an electron
(3) a positron
(2) a neutron
(4) a proton
2.) According to the wave-mechanical model of the atom, an orbital is a region of the most probable location of
(1) an alpha particle
(3) an electron
(2) a gamma ray
(4) a proton
3.) Which phrase describes an atom?
(1) a negatively charged nucleus surrounded by positively charged protons
(2) a negatively charged nucleus surrounded by positively charged electrons
(3) a positively charged nucleus surrounded by negatively charged protons
(4) a positively charged nucleus surrounded by negatively charged electrons
4.) An orbital is defined as a region of the most probable location of
(1) an electron
(3) a nucleus
(2) a neutron
(4) a proton
5.) Which conclusion is based on the “gold foil experiment” and the resulting model of the atom?
(1) An atom is mainly empty space, and the nucleus has a positive charge.
(2) An atom is mainly empty space, and the nucleus has a negative charge.
(3) An atom has hardly any empty space, and the nucleus has a positive charge.
(4) An atom has hardly any empty space, and the nucleus has a negative charge.
6.) Which of these phrases best describes an atom?
(1) a positive nucleus surrounded by a hard negative shell
(2) a positive nucleus surrounded by a cloud of negative charges
(3) a hard sphere with positive particles uniformly embedded
(4) a hard sphere with negative particles uniformly embedded
7.) In the wave-mechanical model, an orbital is a region of space in an atom where there is
(1) a high probability of finding an electron
(2) a high probability of finding a neutron
(3) a circular path in which electrons are found
(4) a circular path in which neutrons are found
8.) The modern model of the atom is based on the work of
(1) one scientist over a short period of time
(2) one scientist over a long period of time
(3) many scientists over a short period of time
(4) many scientists over a long period of time
9.) The region that is the most probable location of an electron in an atom is
(1) the nucleus
(3) the excited state
(2) an orbital
(4) an ion
8
10.) Which statement best describes electrons?
(1) They are positive subatomic particles and are found in the nucleus.
(2) They are positive subatomic particles and are found surrounding the nucleus.
(3) They are negative subatomic particles and are found in the nucleus.
(4) They are negative subatomic particles and are found surrounding the nucleus.
11.) John Dalton was an English scientist who proposed that atoms were hard, indivisible spheres. In the modern
model, the atom has a different internal structure.
a. Identify one experiment that led scientists to develop the modern model of the atom.
b. Describe this experiment.
c. State one conclusion about the internal structure of the atom, based on this experiment.
Base your answers to questions 12 through 14 on the information and diagram below.
One model of the atom states that atoms are tiny particles composed of a uniform mixture of positive and negative
charges. Scientists conducted an experiment where alpha particles were aimed at a thin layer of gold atoms. Most of the
alpha particles passed directly through the gold atoms. A few alpha particles were deflected from their straight-line paths.
An illustration of the experiment is shown below.
12.) Most of the alpha particles passed directly through the gold atoms undisturbed. What does this evidence suggest
about the structure of the gold atoms?
13.) A few of the alpha particles were deflected. What does this evidence suggest about the structure of the gold
atoms?
14.) How should the original model be revised based on the results of this experiment?
9
SUBATOMIC PARTICLES
TOPIC
3.2
What are electrons, protons, and neutrons?
Subatomic Particle
Charge
Relative Mass
Location
How to Calculate/Determine
PROTON
NEUTRON
ELECTRON
Nuclear charge:
Net charge:
OXIDATION NUMBERS
ATOMIC MASS
ATOMIC #
ELEMENT SYMBOL
ELECTRON CONFIGURATION
10
1. How are the atomic number and the number of protons related to each other? ___________________________
2. How do the number of protons, number of neutrons, and the mass number relate to each other?
3. What is the one thing that determines the identity of an atom? ____________________________
4. Fill in the missing values for the chart below.
Element
Name
Atomic
Number
Number
of
Protons
Number
of
Neutrons
carbon
Number
of
Electrons
Mass Number
Nuclear Charge
Nuclear
Symbol
12
8
8
hydrogen
1
6
hydrogen
14
2
nitrogen
14
1
92
2
146
cesium
82
11
12
47
tungsten
108
110
45
24
80
52
silver
107
76
114
11
ASSIGN.
#2
Electrons, Protons, and Neutrons
Regents Practice
1.) The atomic number of an atom is always equal to the number of its
(1) protons, only
(3) protons plus neutrons
(2) neutrons, only
(4) protons plus electrons
1.) Which subatomic particle has no charge?
(1) alpha particle
(3) neutron
(2) beta particle
(4) electron
2.) Which particles are found in the nucleus of an atom?
(1) electrons, only
(3) protons and electrons
(2) neutrons, only
(4) protons and neutrons
3.) What is the total number of neutrons in an atom of an element that has a mass number of 19 and an atomic
number of 9?
(1) 9
(3) 19
(2) 10
(4) 28
4.) A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is
(1) 1
(3) 12
(2) 11
(4) 23
5.) Which statement is true about the charges assigned to an electron and a proton?
(1) Both an electron and a proton are positive.
(2) An electron is positive and a proton is negative.
(3) An electron is negative and a proton is positive.
(4) Both an electron and a proton are negative.
6.) Which statement is true about a proton and an electron?
(1) They have the same masses and the same charges.
(2) They have the same masses and different charges.
(3) They have different masses and the same charges.
(4) They have different masses and different charges.
7.) Which statement concerning elements is true?
(1) Different elements must have different numbers of isotopes.
(2) Different elements must have different numbers of neutrons.
(3) All atoms of a given element must have the same mass number.
(4) All atoms of a given element must have the same atomic number.
8.) What is the total number of electrons found in an atom of sulfur?
(1) 6
(3) 16
(2) 8
(4) 32
12
9.) Which subatomic particle will be attracted by a positively charged object?
(1) proton
(3) electron
(2) neutron
(4) positron
10.) Which two particles have approximately the same mass?
(1) proton and neutron
(3) neutron and electron
(2) proton and electron
(4) neutron and positron
11.) What is the total number of neutrons in the nucleus of a neutral atom that has 19 electrons and a mass number of
39?
(1) 19
(3) 39
(2) 20
(4) 58
12.) Which statement about one atom of an element identifies the element?
(1) The atom has 1 proton.
(2) The atom has 2 neutrons.
(3) The sum of the number of protons and neutrons in the atom is 3.
(4) The difference between the number of neutrons and protons in the atom is 1
13.) Which particles have approximately the same mass?
(1) an electron and an alpha particle
(3) a neutron and an alpha particle
(2) an electron and a proton
(4) a neutron and a proton
14.) What is the charge of the nucleus of an oxygen atom?
(1) 0
(3) +8
(2) -2
(4) +16
13
TOPIC
3.3
ISOTOPES & AVERAGE ATOMIC MASS
How can we discuss the mass of a large sample of atoms of an element?
The mass of an atom comes from which two subatomic particles? ___________________ & ____________________
How do we know how many protons are in an atom? ____________________________________
How do we know how many neutrons are in an atom? Chemists use different symbols to represent the mass number and
atomic number of a given atom. Here’s a couple different ways to represent an atom of carbon:
carbon – 12
Okay, so based on that, the mass of a carbon atom is 12. But what does the Periodic Table give for the mass of an atom of
carbon? _______________
The atomic mass given on the Periodic Table is: the weighted average of an element’s naturally occurring _____________.
So what’s an ISOTOPE?
Example: Isotopes of carbon
subatomic particles
C-12
C-13
C-14
Protons
Neutrons
Electrons
Based on the atomic mass of carbon, which isotope do you think occurs most abundantly? _______________
WHY?
14
CALCULATING ATOMIC MASS (for any element)
atomic mass – the weighted average of an element’s naturally occurring isotopes
(% abundance of isotope 1 in decimal form) x (mass of isotope 1)
(% abundance of isotope 2 in decimal form) x (mass of isotope 2)
+ (% abundance of isotope 3 in decimal form) x (mass of isotope 3)
average atomic mass
EXAMPLES
1. Chlorine has two naturally occurring isotopes, Cl-35 (mass 34.9689 amu) and Cl-37 (mass 36.9659 amu). In the
atmosphere, 32.51% of the chlorine is cl – 37, and 67.49% is Cl-35. What is the atomic mass of atmospheric chlorine?
2.
15
ASSIGN.
#3
Isotopes & Atomic Mass
Regents Practice
1.) An atom of carbon-12 and an atom of carbon-14 differ in
(1) atomic number
(3) nuclear charge
(2) mass number
(4) number of electrons
2.) Hydrogen has three isotopes with mass numbers of 1, 2, and 3 and has an average atomic mass of 1.00794 u. This
information indicates that
(1) equal numbers of each isotope are present
(2) more isotopes have an atomic mass of 2 or 3 than of 1
(3) more isotopes have an atomic mass of 1 than of 2 or 3
(4) isotopes have only an atomic mass of 1
3.) The atomic mass of an element is calculated using the
(1) atomic number and the ratios of its naturally occurring isotopes
(2) atomic number and the half-lives of each of its isotopes
(3) masses and the ratios of its naturally occurring isotopes
(4) masses and the half-lives of each of its isotopes
4.) The nucleus of an atom of K-42 contains
(1) 19 protons and 23 neutrons
(2) 19 protons and 42 neutrons
(3) 20 protons and 19 neutrons
(4) 23 protons and 19 neutrons
5.) Isotopes of an element must have different
(1) atomic numbers
(3) numbers of protons
(2) mass numbers
(4) numbers of electrons
6.) Which statement best explains why most atomic masses on the Periodic Table are decimal numbers?
(1) Atomic masses are determined relative to an H–1 standard.
(2) Atomic masses are determined relative to an O–16 standard.
(3) Atomic masses are a weighted average of the naturally occurring isotopes.
(4) Atomic masses are an estimated average of the artificially produced isotopes.
7.) What is the charge of the nucleus in an atom of oxygen-17?
(1) 0
(3) +8
(2) –2
(4) +17
8.) Which statement concerning elements is true?
(1) Different elements must have different numbers of isotopes.
(2) Different elements must have different numbers of neutrons.
(3) All atoms of a given element must have the same mass number.
(4) All atoms of a given element must have the same atomic number.
16
9.) The nucleus of an atom of cobalt-58 contains
(1) 27 protons and 31 neutrons
(2) 27 protons and 32 neutrons
(3) 59 protons and 60 neutrons
(4) 60 protons and 60 neutrons
10.) An atom of lithium-7 has an equal number of
(1) electrons and neutrons
(2) electrons and protons
(3) positrons and neutrons
(4) positrons and protons
11.) Which quantity can vary among atoms of the same element?
(1) mass number
(3) number of protons
(2) atomic number
(4) number of electrons
12.) Every chlorine atom has
(1) 7 electrons
(2) 17 neutrons
(3) a mass number of 35
(4) an atomic number of 17
Base your answers to question 13 on the information below.
Naturally occurring elemental carbon is a mixture of isotopes. The percent composition of the two most abundant
isotopes is listed below.
• 98.93% of the carbon atoms have a mass of 12.00 atomic mass units.
• 1.07% of the carbon atoms have a mass of 13.00 atomic mass units.
13.) Describe, in terms of subatomic particles found in the nucleus, one difference between the nuclei of carbon-12
atoms and the nuclei of carbon-13 atoms. The response must include both isotopes.
14.) The table below gives information about two isotopes of element X.
Calculate the average atomic mass of element X.
Base your answers to questions 16 through 17 on the data table below, which shows three isotopes of neon.
15.) In terms of atomic particles, state one difference between these three isotopes of neon.
16.) Based on natural abundances, the average atomic mass of neon is closest to which whole number?
17
TOPIC
3.4
ELECTRON CONFIGURATIONS
How are electrons arranged within an atom?
Let’s think back to the history of the development of the atom. Which model gave us the most useful way to look at
electrons?
The electrons in the outermost energy
levels are called:
18
ASSIGN.
#4
Electron Configurations & Bohr Diagrams
Practice
PART I
1. Complete the following electron configurations and Bohr diagrams.
Carbon
e- configuration: ______________
Sodium
e- configuration: ______________
Fluorine
e- configuration: ______________
Aluminum
e- configuration: ______________
Argon
e- configuration: ______________
Sulfur
e- configuration: ______________
19
PART II – Regents Practice
20
TOPIC
3.5
GROUND versus EXCITED STATE
How do electrons change when they’re hit with added energy?
Ground State
Excited State
21
ASSIGN.
#5
Ground vs Excited State
Regents Practice
22
TOPIC
3.6
BRIGHT LINE SPECTRUM
How can we use the behavior of electrons to identify elements?
The structure of atoms of each element is consistent across the entire universe. Helium here on Earth is exactly the same
as helium on the Sun, which is exactly the same as helium from the most distant start we can detect. The elements are the
common building blocks of the Universe.
Each element also leaves a characteristic “fingerprint” that we can detect as an atom moves from the excited state back
down to the ground state.
In terms of electrons and energy states, explain how the lines in the bright-line spectra were generated.
Which elements make up the mixture? How can you tell?
23
ASSIGN.
#6
Bright Line Spectrum
Regents Practice
24
TOPIC
3.7
1)
LEWIS DOT DIAGRAMS
How can we use valence electrons to create a simplified model of the atom?
We will be working with Lewis (electron) dot diagrams more closely when we start to get into Unit 5 (Bonding). For now,
we’ll just introduce how to draw Lewis Dot Structures of atoms.
Example: Draw the Lewis Dot Diagram for carbon.
#
Instructions
Example
1
Write the element’s symbol.
2
Retrieve the electron configuration from the Periodic Table. The last
number in the configuration is the number of valence electrons.
3
Use either an “x” or a dot to represent your electrons. Place the
number of valence electrons around the element symbol.
Octet Rule
A completely filled valence electron shell has ________ electrons.
Exceptions:
25
ASSIGN.
#7
Lewis Dot Structures
Practice
PART I – Drawing Lewis Dot Structures
Draw Lewis Dot Diagrams for the following elements:
Argon
Phosphorous
Silicon
Beryllium
Oxygen
Aluminum
PART II – Regents Practice
1.) What is represented by the dots in a Lewis electron-dot diagram of an atom of an element in Period 2 of the
Periodic Table?
(1) the number of neutrons in the atom
(3) the number of valence electrons in the atom
(2) the number of protons in the atom
(4) the total number of electrons in the atom
2.) What is the total number of valence electrons in an atom of sulfur in the ground state?
(1) 6
(3) 3
(2) 8
(4) 4
3.) Which Lewis electron-dot structure is drawn correctly for the atom it represents?
4.) Which Lewis electron-dot diagram represents a boron atom in the ground state?
5.) In the ground state, which atom has a completely filled valence electron shell?
(1) C
(3) Ne
(2) V
(4) Sb
6.) Which Lewis electron-dot diagram represents a nitrogen atom in the ground state?
Base your answer to # 7 on the electron configuration table shown to the right.
7.) What is the total number of valence electrons in an atom of electron
configuration X?
26
UNIT 3 TEST REVIEW CHECKLIST
Identify where to focus/how to spend your time during this review in class.
Unit Learning Target
1
2
3
4
5
6
7
8
9
10
11
12
13
14
YES.
Got it.
I understand that the modern model of the atom has evolved over a long
period of time through the work of many scientists.
I can relate experimental evidence (i.e. Gold Foil Experiment, Thomson’s
Cathode Ray Experiment) to models of the atom.
I can identify the subatomic particles of an atom (proton, neutron, and
electron).
I know the properties, including mass, charge, and location, of the
subatomic particles.
I can determine the number of protons, neutrons, and electrons in a
neutral atom.
I can differentiate between atomic number, mass number, and average
atomic mass.
I can identify and define isotopes.
I can calculate average atomic mass.
I can distinguish electron configurations between ground and excited
state.
I can write electron configurations.
I can draw Bohr Diagrams for an element.
I can draw Lewis Dot Diagrams for an element.
I can explain the production of bright line spectra.
I can use bright line spectrum to identify an element.
27
Needs
review
NOPE.
Not yet.