Download 4 The Structure of the Atom

4 The Structure
of the Atom
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Write the Big ldea for this chapter.
Use the "What I Know" column to list the things you know about the Big ldea. Then list the
questions you have about the Big ldea in the "What I Want to Find Out" column. As you read the
chapter, fill in the"What I Learned"column.
Whot
KWL
Know
I
What t Wont to Find
Out
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Science Notebook . The Structure of the Atom
53
What I Learned
4 The Structure
of the Atom
1 Early ldeas About Matter
t?fit3(F),6(A)
rUAIN IDEA
Write the Main ldea for this lesson.
*strs=u, VocaeuLaxv
Recall the definition of the Review Vocabulary term.
theory
theonl
frlsw Voe*BUTARY
Define each New Vocabulary term.
Daltont atomic theory
Dalton's alomictheonl
Science Notebook. fhe Structure ofthe Atom
54
1 Early ldeas About
Use
with pages 102-104.
Matter
(continued)
Summarize the effect that Aristotle had on the atomic theory proposed
by Democritus.
lnfer why it was hard for Democritus to defend his ideas.
List the main points of Dalton's atomic theory.
1.
2.
3.
4.
5.
. .'' :
t':
'r' Compare and contrast Democritus' and Dalton's
Science Notebook . The Structure of the Atom
55
ideas.
1 Early ldeas About Matter
Use
with page 104.
(continued)
Discuss Dalton's ideas by completing the following paragraph.
studying
accurately determine the
, Dalton was able
After years of
reactions. His conclusions resulted in
,
of the elements involved in the
the
,
in chemical reactions separate,
explain that
to
which helped to
,ol
,ol
but are not created,
Compare and contrast the atomic theories of Democritus and Dalton.
Mark an X under each name if a statement applies to that person's theory.
Statement
Democritus
Dalton
All matter is made of tiny pieces.
Matter is made of empty space
through which atoms move.
Atoms cannot be divided.
Atoms cannot be created.
Atoms cannot be destroyed.
Different atoms combine in
whole-number ratios to form
compounds.
The properties of atoms vary
based on shape, size, and
movement.
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Different kinds of atoms come in
different sizes and shapes.
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The experiments of the alchemists revealed the properties of some metals and provided the
foundation for the science of chemistry. Although not successful, alchemy proved beneficial to
science. Explain how this example can be applied to modern research.
Science Notebook. The Structure ofthe Atom
56
1 Early ldeas Ahout Matter
(continued)
RTVIEW [T'!
1. MAINIDEA Contrast the methods used by the Greek philosophers and Dalton to study
the atom.
2. Define atom using your own words.
3. Summarize Daltont atomic
4.
theory.
Explain how Dalton's theory of the atom and the conservation of mass are related.
5. Apply
of Element A combine with eight atoms of Element B to produce six
compound particles. How many atoms of Elements A and B does each particle contain?
Are all of the atoms used to form compounds?
Six atoms
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Design a concept map that compares and contrasts the atomic ideas proposed by
Democritus and John Dalton.
o
Science Notebook. The Structure ofthe Atom
57
4 The Structure of the Atom
2
Defining the Atom
IEl3(F),6(A)
[vHAtFd it_rIA
Write the Main ldea for this lesson.
ilevrew Voceu*LsRc
Recall the definition of the ReviewVocabulary term.
model
model
Stlsw UceaBilrARY
Define each New Vocabulary term.
atom
atorn
cathode ray
calhode ray
electron
nucleus
proton
electron
neutron
nucleus
proton
-9
=.
o
neutron
=
6|
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g
Use
with pages 106-107.
,
6
Explain an atom by completing the following statements.
The atom is the
When a group of
atoms
,
the result is known as a
Science Notebook . The Structure of the Atom
58
and act as
a
2
Defining the Atom
Use
with pages 107-'l
10,
(continued)
Summarize the information you learned about cathode ray experiments.
Use Figure 7 for reference.
Cathode Ray
Experiment
Altering the gas in the
tube and the material
used for the
cathode have no effect.
Proves:
Cathode ray is deflected
toward the positively
charged plate by an
electric field.
Cathode ray is
deflected in a
magnetic field.
Proves:
lndicates:
#ffifl
!'tr=f Explain how the cathode ray was discovered.
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i, i Summarize howThomson
discovered the electron.
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Science Notebook. The Structure ofthe Atom
59
2
Defining the Atom
Use
with pages 1 10-114.
(continued)
ldentify the major discoveries about subatomic particles made by the
1
9th century.
1.
3.
QeT [T.? Explain whyThomson's
model was called the plum pudding
model.
Describe Rutherford's model of the atom by completing the following
statements.
1.
Most of an atom consists
of
moving
through
2.
The electrons
are
within the atom by their
to the positively charged
3.
of
many times
The volume
deT [T?
through which the electrons move
than the volume of
Describe Rutherford's model of the
the
is
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atom.
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Science Notebook . The Structure of the Atom
60
2
Defining the Atom
Use
with pages 1 10-1
14.
(continued)
Organize the properties of subatomic particles by completing the table
below. Use Table 3 for reference.
Proton
Electron
Neutron
Symbol
in nucleus
Location
Relative
1+
electrical
charge
Summarize what you have learned about subatomic particles by
completing the following paragraph.
Atoms have
of
of an atom is made up
shape. The
a
that have a positive charge and
of the mass of an atom.
.The nucleus makes up
Most of the area of an
is made up of negatively charged
traveling around the
are held in place by their
the
that have no
charged nucleus.The
to the positive charge of
of the protons and neutrons are almost
.The
to each other while the
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Science Notebook . The Structure of the Atom
61
of the electrons is
2
Defining the Atom
(continued)
REVIEW IT!
7. MAINIDEA Descibe the structure of a typical atom. ldentify where each subatomic
particle is located.
8.
Compare and contrastThomsont plum pudding atomic modelwith Rutherfordt
nuclear atomic model.
9.
Evaluate the experiments that led to the conclusion that electrons are negatively
charged particles found in all matter.
n
ao
1O. Compare the relative charge and mass of each of the subatomic particles,
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1
1. Calculate
What
is
the difference expressed in kilograms between the mass of a proton
and the mass of an electron?
Science Notebook. The Structure ofthe Atom
62
4 The Structure of the Atom
3
How Atoms Differ
EtB6(D)
IVEAIN iL]EA
Write the Main ldea for this lesson.
Rrvrrw llocnsurnns
Recall the definition of the ReviewVocabulary term.
periodic table
periodictable
Nsw VocnsuLARY
Define each New Vocabulary term.
atomic number
alomic number
isotope
mass number
atomic mass unit (amu)
isolope
atomic mass
mass number
atomic mass unrl (amu)
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U
atornic mass
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Ae*trgmrc€$eABUt**Y
Define the following term.
specific
specitic
Science Notebook . The Structure of the Atom
63
3
How Atoms Differ ( continued)
Use
with pages 1 l5-'l
16.
Explain how to use an atomic number to identify an element by
completing the paragraph below.
Each
of an element has a unique number
the overallcharge of an atom
the number
of
of
. lf
.
is
of
the number
Atomic number
:
number
.
of
equals
:
of
Since
number
you know how many one of the three an atom contains,
you also know the
other
the
.
Once you know
the
,
can be used to find the name of the
Solve
Read Example Problem 1 in your text.
Problem
Given the following information about atoms, determine the name
each atom's element and its atomic number.
a. Atomt has1l
protons
of
b. Atom2has2Oelectrons
1. Analyze the Problem
Apply the relationship among atomic number, number of protons,
and number of electrons to determine the name and atomic
number of each element.
2. Solve for the Unknown
a. Atom 1
:
Atomic number :
:
electrons
: number of electrons
The element with an atomic number of 1 is
Atomic number
number of protons
number of
1
b. Atom 2
:
:
Atomic number = number of protons :
The element with an atomic number of
Atomic number
3.
number of protons
number of
electrons
is
Evaluate the Answer
The answers agree
with
and element
given in the periodic table.
Science Notebook. The Structure ofthe Atom
64
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3
How Atoms Differ (continued)
Use
with pages 1 17-118.
Review your understanding of isotopes and mass number by completing
the following paragraph.
lsotopes are elements with
but with
.
The number of neutrons can be
determined by
the atomic numberfrom the
The mass number
.
Solve
is
Read Example Problem 2 in your text.
Problem
You are given two samples of carbon. The first sample, carbon-12, has a
mass number of 12, the second sample, carbon-l3, has a mass number
of 1 3. Both samples have an atomic number of 6. Determine the
number of protons, electrons, and neutrons in each sample.
1. Analyze the Problem
Known:
Carbon-l2
Mass number is
Atomic number is
Carbon-I3
Mass number is
Atomic number
is
Unknown:
o
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-
The number of protons, electrons, and neutrons in each sample.
2. Solve for the Unknown
Number of protons
:
I
number of electrons
:
-
Number of neutrons
:
The number of neutrons for carbon-l3 :
.9
o
o
mass number
atomic number
:
atomic number
E
3
o
:
The number of neutrons for carbon -12
13 12
:
6:
6
3. Evaluate the Answer
The number of neutrons does equal
the
, or
the number of protons.
Science Notebook . The Structure of the Atom
65
the
minus
3
How Atoms Differ (continued)
Use
with pages
1
19-121 I .i I
r'
,
,'
Explain how to calculate atomic mass.
Summarize Fill in the blanks to help you take notes while you read
Example Problem 3.
Problem
in the table in the left
Given the
lsotope Abundance for
Element X
lsotope Mass Percent
(amu) abundance
6x
7x
6.015
7.016
of unknown element
,
margin,
the
the unknown
X. Then,
to treat some
which is used
1. Analyze the problem
Unknown:
Known:
7.59o/o
For isotope
92.41o/o
6X:
ofX:?amu
of element X
MASS:
:
abundance:
For isotope
7X:
mass:
abundance
:
2. Solve for the unknown
Masscontribution:(
6X:
For
Mass contribution :
7X:
For
Mass contribution :
)(
:
:
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=.
Sum the mass contributions to find the atomic mass.
of
X:
{
=
['
to identify the element.
Use the
The element with an atomic mass of 6.939 amu
3.
o
=
6'
is
Evaluate the answer
The number of neutrons does equal the
the
,
or number of
Science Notebook. The Structure ofthe Atom
66
MINUS
3
How Atoms Differ (continued)
AFr.l#rlr
ld:u.vt&w
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!
20. MAINIDEA Explain howthe type of an atom is defined.
2I. Recall Which subatomic
particle identifies an atom
as
that of a particular element?
22. Explain
how the existence of isotopes is related to the fact that atomic masses are not
whole numbers.
23. Calculate Copper
has two isotopes:Cu-63 (abundance
and Cu-65 (abundance :3A.8a/o, mass :
--
69.20/o, mass
:
62.930 amu)
64.928 amu). Calculate the atomic mass
of
copper.
24. Calculate
Three magnesium isotopes have atomic masses and relative abundances
23.985 amu (78.99o/o),24.986 amu (10.00o/o), and 25.982 amu (1 1.01o/o), Calculate the
atomic mass of magnesium.
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=
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Science Notebook. The Structure ofthe Atom
67
of
4 The Structure of the Atom
4
Unstable Nuclei and Radioactive DecaY
ffi3(F),12(A)
Mse$tW
i*i:A
Write the Main ldea for this lesson.
#svrcre €*<e+a:a**v
Reca!lthe definition of the ReviewVocabulary term'
element
elemenl
H=*r W*cs=sL&eY
Define each New VocabularY term.
radioactivity
radioactivity
radiation
radiation
nuclear reaction
nuclear reaction
radioactive decay
alpha radiation
alpha particle
radioaclive decay
nuclear equation
beta radiation
alpha radiation
beta particle
gamma ray
alpha pavticle
nuclear equafion
bda radiation
beta particle
gamma
raY
Science Notebook . The Structure of the Atom
68
4
Unstable Nucleiand Radioactive Decay (continued)
REVIEW
tri
25. MAINIDEA Explain
how unstable atoms gain stability.
26. State what quantities are conserved when balancing
27. Classify
a nuclear reaction.
each of the following as a chemical reaction, a nuclear reaction, or neither.
a. Thorium emits a beta particle.
b. Two atoms share electrons to form a bond.
c. A sample of pure sulfur emits heat energy as it slowly cools.
d.
A piece of iron rusts.
28. Calculate
How much heavier is an alpha particle than an electron?
Create a table showing how each type of radiation affects the atomic number
and the mass number of an atom.
(
a
c
Science Notebook . The Structure of the Atom
70
4
Unstable Nuclei and Radioactive Decay (continued)
Use
with pages 122-124.
Explain radioactivity by completing the paragraph below.
ln chemical reactions, atoms maY be
do not change. The
the
,
but their
rearrangement
only
of the atoms, not the
reactiohs are different. In nuclear reactions,
gain stability by emitting
.
As a result
change.
in the nuclei, the atoms'
will continue emitting
called
,
of
,
until stable nuclei, often of
in a process
a
formed.
, are
Sequence the steps of a nuclear reaction.
A stable, nonradioactive atom is formed.
Radiation is emitted.
The process of radioactive decay continues until the nucleus
stable.
is
An atom has an unstable nucleus.
Distinguish between alpha, beta, and gamma radiation by completing
the table below
Radiation Type
Alpha
symbot
Mass
"
(amu)
(l
Beta
Gamma
H")
1
Charge
/1840
0
Discuss why some elements are radioactive while most elements are not.
Science Notebook.The Structure ofthe Atom
69