Download Atoms The configuration of subatomic particles within an

Name: ____________________________________________________________________________________
UNIT
3
Particle Composition, Pt. 1: Atoms
What’s in an atom of an element? How is it arranged?
Ongoing questions | How are the properties of invisible particles responsible for visible changes?
| What are particles and how can we model their physical behavior?
The configuration of subatomic particles within an atom
is responsible for the atom’s identity, chemical and
physical properties, and behavior.
October 10 – October 27, 2016
Quizzes: _________________________________________
Test date: ________________________________________
Key topics and vocabulary
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Key scientific skills
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Atomic model development: the scientists
o Democritus and Dalton
o Thomson
o Rutherford
o Bohr
o Schrodinger
Rutherford’s Gold Foil experiment
Subatomic particles
o Proton
o Neutron
o Electron
Isotopes and mass number
Average atomic mass
Electron configuration
o Energy level
o Orbitals
o Ground state vs. excited state
Bright line spectra
[email protected]
Modeling using diagrams
Mathematically manipulating equations
Making predictions based on patterns
Stating relationships
Reference Tables
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PERIODIC TABLE!
Table S
Table C (conversions)
mslongshouseofscience.weebly.com
OCTOBER: BLUE & ORANGE CLASSES
SUNDAY
9
MONDAY
10
No School 
TUESDAY
WEDNESDAY
THURSDAY
13C
FRIDAY
11 A
12 B
3.1 Atomic
Theory Intro
3.2 Electrons and 3.3 Rutherford
precision
and the nucleus
3.4 Isotopes
RA: 3.1 Regents
RA: 3.2 Regents
RA: 2.4 Regents
RA: 3.3 Regents
Chemistry work
period
14 D
SAT.
15
3.3 Rutherford
simulation
PS3 Due!
16
17 E
18 S
19 A
20 B
21 C
3.5 Average
atomic mass
3.6 Bohr and
energy levels
3.7 Ground vs.
excited state
3.8 Bright line
spectra
3.9 Schrodinger
and a Mini-Quiz
RA: 3.5 Regents
RA: 3.6 Regents
RA: 2.7 Regents
RA: 3.8 Regents
RA: 3.9 Regents
3.5 M&Mium
mass lab
23
3.7 Flame
test/spectra lab
24 D
25 E
26 S
3.10 Suborbital
configuration
3.11 Element
profile miniproject
3.12 Unit 3
Review
RA: 3.10 Regents
PS4 Due!
3.10 Periodic
Table structure
RA: 3.11 Regents
22
Chemistry work
period
27 A
Unit 3 Test
28 B
29
OCTOBER: RED CLASS
SUNDAY
9
MONDAY
10
No School 
TUESDAY
WEDNESDAY
THURSDAY
11 A
12 B
13C
3.1 Atomic
Theory Intro
3.2 Electrons and 3.3 Rutherford
precision
and the nucleus
RA: 3.1 Regents
RA: 3.2 Regents
FRIDAY
14 D
SAT.
15
3.4 Isotopes
RA: 2.4 Regents
Chemistry work
period
RA: 3.3 Regents
3.3 Rutherford
simulation
PS3 Due!
16
17 E
18 S
19 A
20 B
21 C
3.5 Average
atomic mass
3.6 Bohr and
energy levels
3.7 Ground vs.
excited state
3.8 Bright line
spectra
3.9 Schrodinger
and a Mini-Quiz
RA: 3.5 Regents
RA: 3.6 Regents
RA: 2.7 Regents
RA: 3.8 Regents
RA: 3.9 Regents
3.5 M&Mium
mass lab
23
3.7 Flame
test/spectra lab
24 D
25 E
26 S
3.10 Suborbital
configuration
3.10 Periodic
Table structure
3.12 Unit 3
Review
RA: 3.10 Regents
PS4 Due!
RA: 3.10 Regents
3.11 Element
profile miniproject
22
Chemistry work
period
27 A
Unit 3 Test
Chemistry work
period
28 B
29
UNIT
Atomic Theory: Democritus and Dalton
3.1
What’s so special about atoms?
Chemistry hasn’t been around forever, but postulations about how life and the universe work have.
Hey, ladies. I’m Democritus. I like long walks on Greece’s beaches and
philosophical arguments…in 400 B.C. I propose:
Democritus was scientifically snubbed by philosophers of the day (you may be familiar with Plato and Aristotle). His
ideas went disregarded for almost 1200 years, until John Dalton, an English scientist, decided to make a series of
scientific claims based on experimental evidence surfacing about the structure and composition of matter:
Just how small is an atom?
Find an atom’s RADIUS on ___________________________:
How big is that compared to a meter stick? Use _______________________________ to help:
3.1 Regents Practice
1. Locate the atomic radii of the following elements on
Table S. Convert each radius into meters using
Table C.
Element
Radius (pm)
2. Sample A contains molecules at STP.
Radius (m)
Br
Explain, in terms of the composition, why sample A
represents a pure substance.
Na
__________________________________________
__________________________________________
S
__________________________________________
U
230 x 10-12
OR 2.30 x 10-10
__________________________________________
__________________________________________
__________________________________________
Use the information below to answer questions 3 and 4.
3. Classify potassium aluminum sulfate as an element, compound, or mixture. Justify your answer in terms of types of
atoms and chemical bonds.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
4. Can potassium aluminum sulfate be physically or chemically separated? Justify your answer in terms of types of
matter.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
UNIT
The Electron and Precision
3.2
How can we discuss super-precise, super-tiny measurements?
Dalton’s ideas were far from perfect. However, they provided a basis for future experimentation to try and learn more
about the stuff that makes up everything. J.J. Thomson was one such scientist who tried to add more detail to the
model of the atom proposed by Dalton.
Gas
sample
To explain his findings, Thomson upended one of Dalton’s claims. We CAN, in fact,
break an atom down into smaller parts—subatomic particles called electrons.
Subatomic particle:
Electron:
Those electrons must be embedded in some positively charged sphere (to keep things neutral), kind of like chocolate
chips embedded within a plain cookie.
HOLD UP: We’re getting to a point where we have to talk about precision in measurement. All this atomic stuff is on a
SUPER tiny scale, so every number we can measure counts. Hence, here comes the concept of significant figures:
Number of significant figures:
Look for the first nonzero number!
23
0.145
0.0145
200
200.
50 times 0.103
42 times 0.023
3.2 Regents Practice
Use the information below to respond to questions 1 through 3.
1. Identify the negatively charged particle Thomson discovered. _____________________________________________
2. What does it mean to have “uniform density”?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
3. What does it mean to be “electrically neutral”?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
Use your knowledge of significant figures to respond to questions 4 through 7.
4. The mass of an electron can be reported using a few different units/comparative values. Identify the number of
significant figures in each measurement.
a. 0.000548597 amu : _________________________ sig figs
b. 9.109 x 10-31 kg (ignore the “x 10-31” in your count of sig figs): ___________________________________ sig figs
c. 2.00 x 10-30 lbs (ignore the “x 10-30” in your count of sig figs): ____________________________________ sig figs
d. 1840 times smaller than any other subatomic particle: ____________________________________ sig figs
e. 1840. times smaller than any other subatomic particle ____________________________________ sig figs
5. Which mass measurement contains four significant
figures?
(1) 0.086 g
(2) 0.431 g
(3) 1003 g
(4) 3870 g
6. The measurement 0.41006 g, rounded to three
significant figures, is expressed as
(1) 0.41 g
(2) 0.410 g
(3) 0.4100 g
(4) 0.4101 g
7. A sample of a gas to be used in a cathode ray tube
has a mass of 0.04161 grams and a volume of 3.8
cubic centimeters. To which number of significant
figures should the calculated density of the sample
be expressed?
(1) 5
(2) 2
(3) 3
(4) 4
UNIT
Rutherford and the Nucleus
3.3
How can we learn more about the structure of something we can’t even see?
Thomson’s model opened doors for waves of scientists to see if there was more hidden inside the atom than just tiny
electrons. Trouble is, when the atom is so small, it’s hard to see much. Ernest Rutherford came up with a way to
indirectly “see” the inside of an atom:
LET’S SHOOT STUFF AT A GOLD ATOM AND SEE WHAT HAPPENS!
Rutherford’s ____________________ Experiment
If Thomson is actually right, this experiment will be
super boring. Why?
Experimental Result (Observation)
Explanation of Result (Conclusion)
Dalton’s observations (and subsequent conclusions) led him to add more detail to the developing model of the atom:
3.3 Regents Practice
1. A student conducts a chemical reaction and observes the results. Which of the following statements contained in a
student’s laboratory report is a conclusion?
(1) A gas is evolved (created).
(2) The gas is insoluble (does not dissolve) in water.
(3) The gas is hydrogen.
(4) The gas burns in air.
2. As a result of the gold foil experiment, it was concluded that an atom
(1) Contains protons, neutrons, and electrons
(2) Contains a small, dense, nucleus
(3) Has positrons and orbitals
(4) Is a hard, indivisible sphere
3. The gold foil experiment led to the conclusion that each atom in the foil was composed mostly of empty space
because most alpha particles directed at the foil
(1) Passed through the foil
(2) Remained trapped in the foil
(3) Were deflected by the nuclei in gold atoms
(4) Were deflected by the electrons in gold atoms
4. An experiment in which alpha particles were used to bombard thin sheets of gold foil led to the conclusion that an
atom is composed mostly of
(1) Empty space and has a small, negatively charged nucleus
(2) Empty space and has a small, positively charged nucleus
(3) A large, dense, positively charged nucleus
(4) A large, dense, negatively charged nucleus
5. State one conclusion about the internal structure of the atom that resulted from the gold foil experiment.
_______________________________________________________________________________________
_______________________________________________________________________________________
6. State one conclusion from Rutherford’s experiment that contradicts one conclusion made by Thomson.
_______________________________________________________________________________________
_______________________________________________________________________________________
UNIT
Isotopes and Mass Number
3.4
How can atoms of the same element be different?
Rutherford’s new model of the atom (and the ensuing discovery of the neutron) shook up the way we think about what
makes each element of the Periodic Table unique. We now know that each atom is made up of three different
subatomic particles. Each of these subatomic particles contributes something unique to the atom.
Subatomic Particle
Charge
Location
Mass
Electron
Proton
Neutron
Nuclear charge:
Net charge:
What’s more, all this information gave us a way to start arranging and describing atoms on a nice, organized Table:
14
𝐶
6
Element symbol
Fill in the missing element symbols and circle the two isotopes.
32
16
____
34
17
____
In terms of subatomic particles, explain what makes the two species isotopes.
34
16
____
3.4 Regents Practice
1. The atomic number of an atom is always equal to
the number of its
(1) protons, only
(2) neutrons, only
(3) protons plus neutrons
(4) protons plus electrons
7. Which subatomic particle will be attracted by a
positively charged object?
(1) proton
(2) neutron
(3) electron
(4) positron
2. Which particles are found in the nucleus of an
atom?
(1) electrons, only
(2) neutrons, only
(3) protons and electrons
(4) protons and neutrons
8. Which two particles have approximately the same
mass?
(1) proton and neutron
(2) proton and electron
(3) neutron and electron
(4) neutron and an alpha particle
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
(2) 10
(3) 19
(4) 28
9. 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
4. A neutral atom contains 12 neutrons and 11
electrons. The number of protons in this atom is
(1) 1
(2) 11
(3) 12
(4) 23
5. 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.
6. 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.
10. What is the charge of the nucleus in an atom of
oxygen-17?
(1) 0
(2) -2
(3) +8
(4) +16
11. 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
12. An atom of carbon-12 and an atom of carbon-14
differ in
(1) Atomic number
(2) Mass number
(3) Nuclear charge
(4) Number of electrons
13. Isotopes of an element must have different
(1) Atomic numbers
(2) Mass numbers
(3) Numbers of protons
(4) Numbers of electrons
UNIT
Average Atomic Mass
3.5
How can we discuss the mass of a large sample of atoms of an element?
We’ve determined that the mass of an atom comes from its ___________________ and __________________
Check out the Periodic Table, though.
What’s the deal with the decimal? We can’t have partial protons or neutrons!
Average atomic mass:
I’m an element sample that has 2% of my atoms with a mass of 14 (amu). All my other atoms weigh in at 12
amu. Can we just report my atomic mass on the Periodic Table as 13 amu and call it a day? Why or why not?
Identify the most abundant isotope of fluorine. How do you know? Do all fluorine atoms have this mass?
3.5 Regents Practice
1. The atomic mass of an element is defined as the weighted average mass of that element’s
(1) Most abundant isotope
(3) Naturally occurring isotopes
(2) Least abundant isotope
(4) Natural and artificial isotopes
2. The atomic masses and the natural abundances of the two naturally occurring isotopes of lithium are shown in the
table below.
Which numerical setup can be used to determine the atomic mass of
lithium?
(1) (0.075)(6.02 u) + (0.925)(7.02 u)
(2) (0.925)(6.02 u) + (0.075)(7.02 u)
(3) (7.5)(6.02 u) + (92.5)(7.02 u)
(4) (92.5)(6.02 u) + (7.5)(7.02 u)
Hydrogen has three isotopes with mass number of 1, 2, and 3 and has an average atomic mass of 1.00794 amu. Use this
information to answer questions 1 and 2.
3. This information about hydrogen 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
4. To what number of significant figures is the average
atomic mass of hydrogen expressed?
(1) 1
(2) 3
(3) 5
(4) 6
The table below gives information about two isotopes of element X.
5. In terms of subatomic particles, state one difference between the two isotopes of element X.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
6. Would you expect the atomic mass of element X to be closer to 10 amu or 11 amu? Explain your answer.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
7. Calculate the average atomic mass of element X. A correct answer should include a numerical setup and a
calculated result.
UNIT
Bohr Diagrams and Energy Levels
3.6
How did we first conceptualize the arrangement of electrons?
Despite all the progress made in describing the structure of an atom, a good chemist is never satisfied. Niels
Bohr was one of those unsatisfied chemists.
What’s the deal with those electrons? Why so messy?
Through a series of experiments that we’ll conceptually analyze in the next two lessons, Bohr was able to
come to the conclusion that electrons are organized (configured) in energy levels (shells) that get
progressively farther from the nucleus.
Energy level (shell):
Energy level 1 can hold up to _______ total electrons
Energy level 2 can hold up to _______ total electrons
Energy level 3 can hold up to _______ total electrons
Energy level 4 can hold up to _______ total electrons
Write the electron configuration and draw the Bohr diagram for boron. Indicate which electrons have the most energy.
3.6 Regents Practice
1. Compared to the energy and charge of the
electrons in the first shell of a Be atom, the
electrons in the second shell of this atom have
(1) less energy and the same charge
(2) less energy and a different charge
(3) more energy and the same charge
(4) more energy and a different charge
2. What is the total number of protons in an atom
with the electron configuration 2-8-18-32-18-1?
(1) 69
(2) 79
(3) 118
(4) 197
3. Which element has an atom with the electron
configuration 2-8-8-2?
(1) Mg
(2) Ni
(3) Ca
(4) Ge
4. Which atom in the ground state has an outermost
electron with the most energy?
(1) Cs
(2) K
(3) Li
(4) Na
5. How do the energy and location of an electron in
the third shell of an atom compare to the energy
and location of an electron in the first shell of the
same atom?
(1) In the third shell, an electron has more energy
and is closer to the nucleus
(2) In the third shell, an electron has more energy
and is farther from the nucleus
(3) In the third shell, an electron has less energy
and is closer to the nucleus
(4) In the third shell, an electron has less energy
and is farther from the nucleus
Use the information below to answer questions 6 through 8.
6. State the atomic number and the mass number of this element.
Atomic number: _____________________________
Mass number: ________________________________
7. State the number of electrons in each shell in this atom in the ground state.
Number of e- in first shell: _____________________
Number of e- in second shell: ____________________
8. State one way in which the Bohr model agrees with the Thomson model.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
UNIT
Ground versus Excited State
3.7
How do electrons change when they’re hit with added energy?
Bohr’s conclusions about the structure of the atom came from the analysis of hydrogen atoms (and a lot of
ensuing math). He “hit” hydrogen atoms with a surge of energy and observed the resulting changes. Here’s
the overview of what he concluded he’d seen:
Step 1: Start with an atom
in its “regular” state
Step 2: Add energy to “excite”
an electron to a higher energy
state
Step 3: Watch as electron releases
energy in the form of light as it
returns to its more stable “ground
state”
e- config: ________________
e- config: __________________
e- config: ____________________
________________________
__________________________
____________________________
Ground state:
Excited state:
3.7 Regents Practice
1. Which electron configuration represents the
electrons of an atom in an excited state?
(1) 2-1
(2) 2-7-4
(3) 2-8-7
(4) 2-4
3. Which electron configuration represents the
electrons of a sulfur atom in an excited state?
(1) 2-6-6
(2) 2-7-7
(3) 2-8-4
(4) 2-8-6
2. What must occur when an electron in an atom
returns from a higher energy state to a lower
energy state?
(1) A specific amount of energy is released
(2) A random amount of energy is released
(3) A specific amount of energy is absorbed
(4) A random amount of energy is absorbed
4. During a flame test, a lithium salt produces a
characteristic red flame. This red color is produced
when electrons in excited lithium atoms
(1) Are lost by the atoms
(2) Are gained by the atoms
(3) Return to lower energy states within the atoms
(4) Move to higher energy states within the atoms
An atom in an excited state has an electron configuration of 2-7-2.
5. Write the electron configuration of this atom in the ground state.
_______________________________________
6. Explain, in terms of subatomic particles, why this excited atom is electrically neutral.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
7. Using the Bohr model, describe the changes in electron energy and electron location when an atom changes from
ground state to excited state.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
An atom of fluorine-19 has an electron configuration of 2-6-1.
8. Explain why the number of electrons in the second and third shells show that this atom is in an excited state.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
9. What is the total number of neutrons in this atom? ____________________________________________________
10. Write an isotopic notation of this isotope of this element. Your response must include the atomic number, the mass
number, and the symbol of this isotope.
UNIT
Bright Line Spectra
3.8
How can we use the behavior of electrons to design and discover?
The structure of atoms of each element is consistent across the entire universe. Read that sentence again, because it’s
kind of mind-boggling. Helium here on Earth is exactly the same as helium on the Sun, which, in turn, is exactly the
same as helium from the most distant star 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 excited state back
down to ground state
Bright-line spectrum:
This “fingerprint” is more precise than the color seen on a flame test (just heating and observing), since a bright-line
spectrum breaks down the visible light into its component wavelengths. Let’s take a look at what that means/looks like:
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?
3.8 Regents Practice
1. A specific amount of energy is emitted when excited
electrons in an atom in a sample of an element
return to the ground state. This emitted energy can
be used to determine the
(1) Mass of the sample
(2) Volume of the sample
(3) Identity of the element
(4) Number of particles of the element
2. The bright-line spectrum of sodium is produced
when energy is
(1) Absorbed as electrons move from higher to
lower electron shells
(2) Absorbed as electrons move from lower to
higher electron shells
(3) Released as electrons move from higher to
lower electron shells
(4) Released as electrons move from lower to
higher electron shells
3. The diagram below represents the bright-line spectra of four elements and a bright-line spectrum produced by a
mixture of three of these elements.
Which element is not present in the mixture?
(1) A
(3) X
(2) D
(4) Z
Fireworks that contain metallic salts such as sodium, strontium, and barium can generate bright colors. A technician
investigates what colors are produced by the metallic salts by performing flame tests. During a flame test, a metallic salt
is heated in the flame of a gas burner. Each metallic salt emits a characteristic colored light in the flame.
4. State how bright-line spectra viewed through a spectroscope can be used to identify the metal ions in the salts used
in the flame tests.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
5. Explain, in terms of electrons, how a strontium salt emits colored light.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
6. Explain why the electron configuration of 2-7-1-1 represents a sodium atom in an excited state.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
UNIT
Schrodinger and the Orbital
3.9
How did modern physics upend the model of the atom?
Bohr’s atomic model is so neat, tidy, and precise. Heck, the Regents chemistry curriculum likes the Bohr model so much
it’s almost all they use. Unfortunately, life ain’t neat, tidy, or precise. Erwin Schrodinger gets that. That’s why he came
through with some quantum physics to rock your world and, once more, transform our thinking about atomic structure.
Oh you need me? I’ll be right over here…probably.
Schrodinger maintained that electrons were still organized by their energies; however, he recognized that we can’t know
exactly where they are. We can just give our best guess.
Orbital:
There will be a multiple-choice question on Part A of the Regents exam in June asking you about what an orbital is. Be
ready for it.
3.9 Regents Practice
1. According to the wave-mechanical model, an orbital
is defined as the
(1) Circular path for electrons
(2) Circular path for protons
(3) Most probable location of electrons
(4) Most probable location of protons
2. An orbital of an atom is defined as the most
probable location of
(1) An electron
(2) A neutron
(3) A positron
(4) A proton
3. The modern model of the atom show that electrons
are
(1) Orbiting the nucleus in fixed paths
(2) Found in regions called orbitals
(3) Combined with neutrons in the nucleus
(5) Located in a solid sphere covering the nucleus
4. Which phrase describes an atom?
(1) A positively charged electron cloud surrounding
a positively charged nucleus
(2) A positively charged electron cloud surrounding
a negatively charged nucleus
(3) A negatively charged electron cloud
surrounding a positively charged nucleus
(4) A negatively charged electron cloud
surrounding a negatively charged nucleus
5. Which group of atomic models is listed in historical
order from the earliest to the most recent?
(1) Hard-sphere model, wave-mechanical model,
electron-shell model
(2) Hard-sphere model, electron-shell model,
wave-mechanical model
(3) Wave-mechanical model, electron-shell model,
hard-sphere model
(4) Electron-shell model, wave-mechanical model,
hard-sphere model
Unit 3 Review Questions
6. Compared to the charge of a proton, the charge of
an electron has
(1) A greater magnitude and the same sign
(2) A greater magnitude and the opposite sign
(3) The same magnitude and the same sign
(4) The same magnitude and the opposite sign
7. Which notation represents an atom of sodium with
an atomic number of 11 and a mass number of 24?
(1) 24
11𝑁𝑎
(2) 11
24𝑁𝑎
(3) 13
11𝑁𝑎
(4) 35
11𝑁𝑎
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.
UNIT
3.10
9. Elements on the modern Periodic Table are
arranged in order of increasing
(1) Atomic mass
(2) Atomic number
(3) Number of neutrons
(4) Number of outermost electrons
10. Each diagram below represents the nucleus of a
different atom.
Which diagrams represent nuclei of the same
element?
(1) D and E, only
(2) D, E, and Q
(3) Q and R, only
(4) Q, R, and E
Suborbitals, Electron Configuration, and the Periodic Table
How can the arrangement of electrons provide insight to the arrangement of the PT?
In order to better understand why the Periodic Table and its elements look the way they do, we’re going to dig a bit
deeper into Schrodinger’s model. These ideas are at the heart of advanced chemistry and explain near EVERYTHING.
Schrodinger tells us that each of Bohr’s energy levels actually contains a specific number of “sublevels.”
Currently, we have only observed 4 types of sublevels, abbreviated with letters: s, p, d, and f.
Each sublevel has a different size/shape and fits a different number of orbitals. Each orbital can hold up to 2 electrons.
It’s kind of like a weird hotel. The energy level tells you what floor you’re on. The sublevel tells you which wing—each
wing has a different number of available rooms (orbitals). Each room can hold 2 occupants (electrons).
Sublevel (“wing”)
s
p
d
f
# of Orbitals (“rooms”)
1
3
5
7
Max # of electrons (“occupants”)
2
6
10
14
Have you ever wondered why the Periodic Table looks like a weird castle-like thing? Check out the size of the “blocks”
that make up the different sections of the Periodic Table:
1s
2s
2p
3s
3p
3d
4s
4p
4d
4f
5s
5p
5d
5f
6s
6p
6d
7s
7p
(no more level-6 sublevels have been observed yet)
(no more level-7 sublevels have been observed yet)
Let’s “translate” electron configurations from your Reference Table into richer Schrodinger-based configurations.
Element
Bohr e- Configuration
Schrodinger e- Configuration
He (helium)
Be (beryllium)
F (fluorine)
K (potassium)
Fe (iron)
Kr (krypton)
Which sublevels do the maximum 8 total electrons of energy level 2 come from? _____________ and ______________
Which sublevels do the maximum 18 total electrons of energy level 3 come from? ________, ________, and ________
The concept of energy levels is stressed in Regents Chemistry; however, the concept of sublevels provides a
more powerful and accurate understanding of the Periodic Table and the behavior of its elements.
3.10 Regents Practice
1. Compared to the maximum number of electrons
that can occupy the d sublevel, the maximum
number of electrons that can occupy the p sublevel
(1) Is smaller by 2 electrons
(2) Is smaller by 4 electrons
(3) Is greater by 2 electrons
(4) Is greater by 4 electrons
4. Which sublevels are occupied in the outermost
energy level of an argon atom in the ground state?
(1) 3s and 3d
(2) 3s and 3p
(3) 2s and 3p
(4) 2p and 3d
2. The total number of orbitals in the d sublevel is
(1) 1
(2) 3
(3) 5
(4) 7
5. Which of the following elements has all of its
sublevels completely filled?
(1) Li
(2) B
(3) N
(4) Ne
3. Which element has atoms in the ground state with
a sublevel that is only half-filled?
(1) Helium
(2) Beryllium
(3) Nitrogen
(4) Neon
6. What is the total number of occupied sublevels in
an atom of chlorine in the ground state?
(1) 1
(2) 3
(3) 5
(4) 9
7. Write the electron configuration, using Bohr AND sublevel notation, for the following elements
Element
Bohr e- Configuration
Schrodinger e- Configuration
N (nitrogen)
Mg (magnesium)
As (astatine)
Al (aluminum)
Tc (technetium)
8. Compare the properties of the model of the atom proposed by Thomson with those of the wave-mechanical model
of the atom as described by Schrodinger.
Regents Practice Answer Key
3.1
3.3
1.
Element
Br
Radius (pm)
117
Na
160.
S
104
U
230.
Radius (m)
117 x 10-12
OR 1.17 x 10-10
160 x 10-12
OR 1.60 x 10-10
104 x 10-12
OR 1.04 x 10-10
230 x 10-12
OR 2.30 x 10-10
2. All particles are the same; Sample A has only
one type of molecule (made by chemically
bonding 2 different atoms); Sample A is not a
mixture
3. Potassium aluminum sulfate is a compound
because it is composed of more than one type
of atom chemically bonded in a fixed
proportion.
4. Potassium aluminum sulfate can be chemically,
not physically, separated because it is a
compound (meaning it has different types of
atoms connected by chemical bonds that could
be broken).
3.2
1. Electron
2. Mass is spread equally over the entire volume—
no areas are packed/condensed more tightly
than others
3. The amount of positive and negative charge is
equal (“cancels out”)
4. a. 6
b. 4
c. 3
d. 3
e. 4
5. 3
6. 2
7. 2 (limited by the 2 sig figs of the volume…the
“weakest link”)
1.
2.
3.
4.
5.
3
2
1
2
The atom is made mainly of empty space OR
The atom contains a small, dense positively
charged center (nucleus)
6. Positive charge is concentrated in the nucleus,
not uniformly throughout the atom OR
The atom is mostly empty space, not uniform
positive charge
3.4
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
1
4
2
2
4
4
3
1
1
3
1
2
2
3.5
1.
2.
3.
4.
5.
3
1
3
4
The two isotopes of element X have a different
number of neutrons
6. The atomic mass of element X should be closer
to 11 amu because the isotope with a mass of
11 is more abundant than the isotope with a
mass of 10.
19.91
7. 𝐴𝑡𝑜𝑚𝑖𝑐 𝑚𝑎𝑠𝑠 = ( 100 ) (10.01) +
80.09
(
)(11.01)
100
𝐴𝑡𝑜𝑚𝑖𝑐 𝑚𝑎𝑠𝑠 = (0.1991)(10.01) +
(0.8009)(11.01)
𝐴𝑡𝑜𝑚𝑖𝑐 𝑚𝑎𝑠𝑠 = 1.992991 + 8.817909
Atomic mass = 10.81 (4 sig figs in problem)
3.6
3.8
1.
2.
3.
4.
5.
6.
3
2
3
1
2
Atomic number: 4
Mass number: 9
7. First shell: 2
Second shell: 2
8. Both models include electrons; both models are
electrically neutral
3.7
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
2
1
2
3
2-8-1
The atom has the same number of negatively
charged electrons as it does positively charged
protons.
When an atom changes from ground state to
excited state, one of its electrons absorbs a
specific amount of energy and moves from a
lower energy level/shell to a higher energy
level/shell.
One electron has moved into the third shell
before the lower-energy second shell was full.
10
19
9𝐹
1.
2.
3.
4.
3
3
3
The bright-line spectra “fingerprint” seen
through a spectroscope can be compared to the
known spectra “fingerprints” of metal ions.
Shared spectral lines show that a metal ion
must be present in the tested salt.
5. A strontium salt absorbs a specific amount of
energy, changing one of its electrons from its
ground state to a higher-level excited state.
The atom emits colored light when an excited
electron releases energy when returning back
to its ground state from a higher energy
level/shell.
6. The ground state of a sodium atom is 2-8-1.
The second shell is no longer full; an electron
has been excited to a higher energy level.
3.9
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
3
1
2
3
2
4
1
4
2
2
3.10
1.
2.
3.
4.
5.
6.
7.
2
3
3
2
4
3 (1s, 2s, 2p, 3s, and 3p are occupied)
Bohr e- Configuration
Element
Schrodinger e- Configuration
N (nitrogen)
2-5
1s22s22p3
Mg (magnesium)
2-8-2
1s22s22p63s2
As (astatine)
2-8-18-5
1s22s22p63s23p64s23d104p3
Al (aluminum)
2-8-3
1s22s22p63s23p1
Tc (technetium)
2-8-18-13-2
1s22s22p63s23p64s23d104p65s24d5
8. While Thomson suggested that electrons were embedded in a uniform sphere of positive charge, Schrodinger’s
wave-mechanical model describes electrons as being most likely to exist in orbitals that surround the nucleus—a
positively charged, dense center of the atom.