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© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 1: Properties of MatterUNIT 2: Matter and Energy RM 1
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© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 1: Properties of Matter
density the amount of matter in a given amount of space
mass amount of matter in a substance
grams unit of measurement for mass
cm3 or mL units of measurement for volume
metalmalleable, shiny, good conductor of heat
and electricity, located on the left side of the Periodic Table
nonmetal brittle, poor conductor, dull luster, located on the right side of the zigzag line on the Periodic Table
metalloid has properties similar to metals and nonmetals, located along the zigzag line on the Periodic Table
luster ability of an object to reflect light
conductivity ability to transmit heat and/or electricity
malleable able to be hammered into sheets
g/cm3 or g/ml units of measurement for density
volume the amount of space an object takes up
Properties of Matter Card Sort
UNIT 2: Matter and Energy RM 2
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Properties of Matter Vocabulary
Lesson 1: Properties of MatterUNIT 2: Matter and Energy RM 3
the
amou
nt o
f mat
ter
in
a gi
ven
amou
nt o
f spa
ce
amou
nt o
f mat
ter
in a
su
bsta
nce
unit
of m
easu
rem
ent f
or m
ass
units
of m
easu
rem
ent f
or
volu
me
mal
leab
le, s
hiny
, goo
d co
nduc
tor
of h
eat a
nd
elec
tric
ity, l
ocat
ed o
n th
e le
ft si
de o
f the
Per
iodi
c Ta
ble
britt
le, p
oor
cond
ucto
r, du
ll lu
ster
, loc
ated
on
the
right
si
de o
f the
zig
zag
line
on th
e P
erio
dic
Tabl
e
has
prop
ertie
s si
mila
r to
m
etal
s an
d no
nmet
als,
loca
ted
alon
g th
e zi
gzag
line
on
the
Per
iodi
c Ta
ble
abili
ty o
f an
obje
ct to
ref
lect
lig
ht
abili
ty to
tran
smit
heat
and
/or
elec
tric
ity
able
to b
e ha
mm
ered
into
sh
eets
units
of m
easu
rem
ent f
or
dens
ity
the
amou
nt o
f spa
ce a
n ob
ject
ta
kes
up
the
amou
nt o
f mat
ter
in
a gi
ven
amou
nt o
f spa
ce
amou
nt o
f mat
ter
in a
su
bsta
nce
unit
of m
easu
rem
ent f
or m
ass
units
of m
easu
rem
ent f
or
volu
me
mal
leab
le, s
hiny
, goo
d co
nduc
tor
of h
eat a
nd
elec
tric
ity, l
ocat
ed o
n th
e le
ft si
de o
f the
Per
iodi
c Ta
ble
britt
le, p
oor
cond
ucto
r, du
ll lu
ster
, loc
ated
on
the
right
si
de o
f the
zig
zag
line
on th
e P
erio
dic
Tabl
e
has
prop
ertie
s si
mila
r to
m
etal
s an
d no
nmet
als,
loca
ted
alon
g th
e zi
gzag
line
on
the
Per
iodi
c Ta
ble
abili
ty o
f an
obje
ct to
ref
lect
lig
ht
abili
ty to
tran
smit
heat
and
/or
elec
tric
ity
able
to b
e ha
mm
ered
into
sh
eets
units
of m
easu
rem
ent f
or
dens
ity
the
amou
nt o
f spa
ce a
n ob
ject
ta
kes
up
Properties of Matter Vocabulary
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 1: Properties of Matter
Page 1 of 4
Choose the best answer for each question.
Use the following diagrams to answer questions 1–4.
Which diagram best models the particles in —
1 air?
2 wood?
3 milk?
4 In which diagram do the particles have the most energy?
Assessment—Properties of Matter
UNIT 2: Matter and Energy RM 4
A B C
200 mL
150
100
50
50
100
150
mL 0+5%+5%
REGION 4Made in USA
250 mL
APPR
OXI
MAT
E VO
LUM
ES
200 mL
150
100
50
50
100
150
mL 0+5%+5%
REGION 4Made in USA
250 mL
APPR
OXI
MAT
E VO
LUM
ES
200 mL
150
100
50
50
100
150
mL 0+5%+5%
REGION 4Made in USA
250 mL
APPR
OXI
MAT
E VO
LUM
ES
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 1: Properties of MatterUNIT 2: Matter and Energy RM 4 continued
Page 2 of 4
5 Which of the following elements has the physical property of malleability?
A Copper
B Carbon
C Iodine
D Oxygen
6 All of the following elements are metals except —
F lead
G iron
H gold
J silicon
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 1: Properties of MatterUNIT 2: Matter and Energy RM 4 continued
Page 3 of 4
7 Twenty milliliters of a liquid has a mass of 25 grams. What is the density of this substance?
A 0.8 g/mL
B 1 g/mL
C 1.25 g/mL
D 500 g/mL
8 The volume of a 34-gram rock is determined by water displacement to be 9 mL. Which of the following will happen if this object is placed in a container of water?
F H
G J
rock
water
rock
water
rock
water
rockwater
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 1: Properties of Matter
Page 4 of 4
UNIT 2: Matter and Energy RM 4 continued
9 A student uses a triple beam balance to measure mass. What unit of measurement should the student use?
A mL
B g
C cm3
D g/mL
10 Tools needed to test the density of unknown liquids most likely include —
F thermometer, graduated cylinder, fire blanket
G graduated cylinder, triple beam balance, safety goggles
H meter stick, triple beam balance, microscope
J safety goggles, apron, fire blanket
11 Determine the density for a material that has a mass of 10 grams and a volume of 20 mL. Grid the answer in below.
Texas Education AgencyStudent Assessment Division
Fall 2010
State of Texas Assessments of Academic Readiness (STAAR™)Griddable Items for Science and Mathematics
For the general science and mathematics assessments, the STAAR program will use a type of open-ended question known as a griddable item. The purpose of griddable items is to provide students opportunities to derive answers independently without being infl uenced by answer choices provided with the questions. Most science and mathematics assessments will include 3 to 5 griddable items.
Griddable Items for STAAR Grades 3–8 Assessments• The correct answer will be a positive number.
• The answer grids include a fi xed decimal point with the exception of grade 3, which does not have a decimal point.
• Students must enter their answer in the correct columns with respect to the fi xed decimal point.
• Students must enter their answer in the boxes and then fi ll in the corresponding bubbles.
• Students do not have to use all the boxes.
• Extra zeros may be fi lled in (either before or after the answer) as long as their placement does not affect the value of the answer.
Grade 3 Assessment Grades 4–5 Assessments Grades 6–8 Assessments
Griddable Items for STAAR EOC Assessments
• The correct answer can be a positive or a negative number. If the answer is a negative number, students must enter a negative sign. If no sign is marked, the answer will default to a positive number.
• The answer grid includes a fl oating decimal point. If the answer is a decimal number, students must enter a decimal point.
• Students must enter their answer in the boxes (paper and online) and then fi ll in the corresponding bubbles (paper only).
• Students do not have to use all the boxes and can place their answer in any set of consecutive boxes.
• Extra zeros may be fi lled in (either before or after the answer) as long as their placement does not affect the value of the answer.
End-of-Course Assessments
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
+
– 0
9
1
.. . . . . .
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
0
9
1
2
3
4
5
6
7
8
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Before Learning
StatementsAfter
Learning
A D Different elements are composed of the same kind of atoms. A D
A D The atom is composed of protons, neutrons, and electrons. A D
A D Most of an atom’s mass is composed of protons and neutrons. A D
A D An atom’s volume is mostly the empty space of the electron cloud. A D
A D Neutrons have a negative charge. A D
A D It is impossible to determine the exact location of electrons in the atom at any moment. A D
A D Neutral atoms have the same number of protons and electrons. A D
A D The protons determine the identity of an element. A D
Anticipation Guide—Atomic Structure
Before Learning
StatementsAfter
Learning
A D Different elements are composed of the same kind of atoms. A D
A D The atom is composed of protons, neutrons, and electrons. A D
A D Most of an atom’s mass is composed of protons and neutrons. A D
A D An atom’s volume is mostly the empty space of the electron cloud. A D
A D Neutrons have a negative charge. A D
A D It is impossible to determine the exact location of electrons in the atom at any moment. A D
A D Neutral atoms have the same number of protons and electrons. A D
A D The protons determine the identity of an element. A D
Anticipation Guide—Atomic Structure
UNIT 2: Matter and Energy RM 5Lesson 2: Atomic Structure
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
1 proton1 neutron
Both neutrons and protons have a mass of approximately 1 amu.
1 proton
1 electron
An electron has very little mass when compared to a proton.
1 proton
1836electrons
It takes 1836 electrons to equal the mass of just one proton.
Size of Subatomic Particles
UNIT 2: Matter and Energy RM 6Lesson 2: Atomic Structure
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Size of an Atom
Lesson 2: Atomic Structure UNIT 2: Matter and Energy RM 7
If the nucleus of an atom has a diameter of 1 inch, . . .
. . . then the electron cloud would have a diameter of about 1.6 miles.
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Atomic Structure
Lesson 2: Atomic Structure UNIT 2: Matter and Energy RM 8
1 2 3
4 5 6
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Gateways to Science, STAAR Edition, Grade 8
Atomic Structure Concept Map
UNIT 2: Matter and Energy RM 9Lesson 2: Atomic Structure
WORD BANKatomelectronelectron cloudnegative chargeneutral or no chargeneutronnucleuspositive chargeproton
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8 Page 1 of 5
Choose the best answer for each question.
1 A student cuts a piece of copper wire into the smallest possible pieces. Which statement best describes
the smallest piece of copper wire?
A The chemical properties of the copper change as the wire is cut.
B The smallest piece of wire is no longer copper.
C The copper changes properties and becomes a new element.
D The wire is still copper and does not change by cutting.
2 Which table best summarizes the subatomic particles and their electrical charge?
F H
G J
RM 10: Assessment—Atomic Structure
UNIT 2: Matter and Energy RM 10Lesson 2: Atomic Structure
proton negative
neutron positive
electron no charge
proton positive
neutron negative
electron no charge
proton positive
neutron no charge
electron negative
proton no charge
neutron positive
electron negative
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8 Page 2 of 5
UNIT 2: Matter and Energy RM 10 continuedLesson 2: Atomic Structure
3 Which diagram best represents the relationship between masses of subatomic particles?
Aproton electron
Cproton
neutron
Bproton
electron
Delectronneutron
Use the model below and the Periodic Table to answer questions 4–8.
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8 Page 3 of 5
UNIT 2: Matter and Energy RM 10 continuedLesson 2: Atomic Structure
Use the diagram to answer questions 4–8.
Q
S
T
R
4 Which letter represents the protons?
F Q
G R
H S
J T
5 Which letter represents the neutrons?
A Q
B R
C S
D T
6 Which letter represents the electrons?
F Q
G R
H S
J T
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8 Page 4 of 5
UNIT 2: Matter and Energy RM 10 continuedLesson 2: Atomic Structure
7 Which letter represents the nucleus?
A Q
B R
C S
D T
8 What is the name of the element represented in the model?
F Beryllium
G Boron
H Oxygen
J Fluorine
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8 Page 5 of 5
Lesson 2: Atomic Structure UNIT 2: Matter and Energy RM 10 continued
9 Which statement best describes the location of subatomic particles?
A The protons and electrons are in the nucleus, while the neutrons are in the cloud outside the nucleus.
B The neutrons are in the nucleus, while the protons and electrons are in the cloud outside the nucleus.
C The electrons and neutrons are in the nucleus, while the protons are in the cloud outside the nucleus.
D The protons and neutrons are in the nucleus, while the electrons are in the cloud outside the nucleus.
10 An atom of an element contains 20 protons. What is the identity of the element?
F Argon
G Calcium
H Neon
J Potassium
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Particle
Location Charge Mass
Inside the
Nucleus
Outside the
Nucleus
Electron Cloud
Positive NegativeNo
Charge1 amu
Less than 1 amu
proton
electron
neutron
Particle
Location Charge Mass
Inside the
Nucleus
Outside the
Nucleus
Electron Cloud
Positive NegativeNo
Charge1 amu
Less than 1 amu
proton
electron
neutron
Particle
Location Charge Mass
Inside the
Nucleus
Outside the
Nucleus
Electron Cloud
Positive NegativeNo
Charge1 amu
Less than 1 amu
proton
electron
neutron
Particle
Location Charge Mass
Inside the
Nucleus
Outside the
Nucleus
Electron Cloud
Positive NegativeNo
Charge1 amu
Less than 1 amu
proton
electron
neutron
Subatomic Particles Table
UNIT 2: Matter and Energy RM 11Lesson 3: Determining Subatomic Particles
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 3: Determining Subatomic ParticlesUNIT 2: Matter and Energy RM 12
Determining Subatomic Particles
9
F18.998
Fluorine
element symbol
atomic number
atomic massround to determine the
mass numberelement name
Atomic Number = Number of Protons = Number of Electrons
A = P = E
Mass Number – Atomic Number = Number of Neutrons
M – A = N
Here is another way to determine protons, neutrons, and electrons using the mnemonic APEMAN:
Fluorine (F)
Atomic number 9
Protons 9
Electrons 9
Mass number 19
–Atomic number 9
Neutrons 10
© REGION 4 EDUCATION SERVICE CENTER. ALL RIGHTS RESERVED.
Gateways to Science, STAAR Edition, Grade 8
Lesson 3: Determining Subatomic Particles
Name of
Element
Chemical Symbol
Atomic Number
Mass Number
Number of
Protons
Number of
Neutrons
Number of
Electrons
1 helium
2 boron
3 neon
4 sulfur
5 tin
6 carbon
7 potassium
8 magnesium
9 calcium
10 mercury
11 gold
UNIT 2: Matter and Energy RM 13
A = P = E M – A = N
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Lesson 3: Determining Subatomic Particles
Page 1 of 2
Assessment—Determining Subatomic Particles
UNIT 2: Matter and Energy RM 14
Choose the best answer for each question.
Key
proton = positive charge
neutron = no charge
electron = negative charge
1 What is the atomic number of the atom in this model?
2 What is the mass number of the atom in this model?
3 What is the name of the element represented in this model?
4 What is the chemical symbol of the element represented in this model?
5 What is the atomic number of the atom in this model?
6 What is the mass number of the atom in this model?
7 What is the name of the element represented in this model?
8 What is the chemical symbol of the element represented in this model?
9 What is the atomic number of the atom in this model?
10 What is the mass number of the atom in this model?
11 What is the name of the element represented in this model?
12 What is the chemical symbol of the element represented in this model?
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Lesson 3: Determining Subatomic Particles
Page 2 of 2
UNIT 2: Matter and Energy RM 14 continued
13 An atom of an element contains 14 protons. What is the identity of this element?
A Boron
B Chlorine
C Nitrogen
D Silicon
14 Which of the following elements contains the greatest amount of protons?
F Chlorine
G Hydrogen
H Oxygen
J Sulfur
15 Which of the following elements contains the least amount of electrons?
A Aluminum
B Calcium
C Fluorine
D Neon
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UNIT 2: Matter and Energy RM 15Lesson 4: The Bohr Model and Valence Electrons
Matching Cards with Descriptions
nucleussubatomic particle
with a negative charge; located in the electron cloud
electron cloudsubatomic particle
with no charge; located in the nucleus
neutronthe number of protons found in an atom
of a specific element
electron contains most of the atom’s mass
protonthe number of protons and
neutrons located in the nucleus
atomic numbertakes up most of the atom’s space;
located outside the nucleus
mass number
subatomic particle with a positive charge;located in the nucleus
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Atomic Model Cards
UNIT 2: Matter and Energy RM 16Lesson 4: The Bohr Model and Valence Electrons
P: 1N: 0
P: 5N: 6
P: 9N: 10
P: 12 N: 12
P: 2N: 2
P: 6N: 6
P: 10N: 10
P: 13N: 14
P: 3N: 4
P: 7N: 7
P: 11 N: 12
P: 14 N: 14
P: 4N: 5
P: 8N: 8
P: 15N: 16
P: 16N: 16
P: 17N: 18
P: 18 N: 22
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Periodic Table Template
UNIT 2: Matter and Energy RM 17Lesson 4: The Bohr Model and Valence Electrons
2 He
4.00
26H
eliu
m
7 N14
.007
Nit
rog
en
8 O15
.999
Oxy
gen
9 F18
.998
Flo
uri
ne
10 Ne
20.1
79N
eon
15 P30
.974
Ph
osp
ho
rus
16 S32
.066
Su
lfu
r
17 Cl
35.4
53C
hlo
rin
e
18 Ar
39.9
48A
rgo
n
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 17 continued
1 H1.
008
Hyd
rog
en
3 Li
6.94
1L
ith
ium
4 Be
9.01
2B
eryl
lium
5 B10
.81
Bo
ron
6 C12
.011
Car
bo
n
11 Na
22.9
90S
od
ium
12 Mg
24.3
05M
agn
esiu
m
13 Al
26.9
82A
lum
inu
m
14 Si
28.0
86S
ilico
n
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 17 continued
Periodic Table Answer Key
P: 1N: 0
P: 5N: 6
P: 9N: 10
P: 12 N: 12
P: 2N: 2
P: 6N: 6
P: 10N: 10
P: 13N: 14
P: 3N: 4
P: 7N: 7
P: 11 N: 12
P: 14 N: 14
P: 4N: 5
P: 8N: 8
P: 15N: 16
P: 16N: 16
P: 17N: 18
P: 18 N: 22
Hydrogen
Helium
Lithium
Beryllium
Chlorine
Boron
Carbon
Nitrogen
Oxygen
Argon
Fluorine
Neon
Sodium
Phosphorus
Magnesium
Aluminum
Silicon
Sulfur
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1 What do you notice about the number of electrons that fill up the first ring?
2Looking at the models, what could you say about the amount of electrons found in the second ring?
3Looking at the models, how many electrons can the first energy level hold before it is considered “full” or “filled”?
4Looking at the models, how many electrons can the second energy level hold before it is considered “full” or “filled”?
5 How many energy levels are located in atoms of the fourth period elements?
6How many electrons are found in the outermost energy level in the fourth group?
7 What is a valence electron?
8Looking at the models, how many valence electrons are located in the outermost energy level for elements in Group 1 (1A)?
9Looking at the models, how many valence electrons are located in the outermost energy level for elements in Group 14 (4A)?
10Looking at the models, how many valence electrons are located in the outermost energy level for elements in Group 17 (7A)?
11 How many valence electrons are located in the last group (8A)?
Questions for Students
Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 18
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For each row, count and record the number of rings in the corresponding circle. Identify the number of electrons located in the outermost energy level for each column and record in the corresponding triangle.
1
H
2
Li Be
Na Mg
18 (8A)
13 (3A) 14 (4A) 15 (5A) 16 (6A) 17 (7A)
He
B C N O F Ne
Al Si P S Cl Ar
Periodic Table Patterns
For each row, count and record the number of rings in the corresponding circle. Identify the number of electrons located in the outermost energy level for each column and record in the corresponding triangle.
1
H
2
Li Be
Na Mg
18 (8A)
13 (3A) 14 (4A) 15 (5A) 16 (6A) 17 (7A)
He
B C N O F Ne
Al Si P S Cl Ar
Periodic Table Patterns
Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 19
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 20
Atoms and Their Energy Levels
Hydrogen
Lithium
Helium
Nitrogen
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Determining Electrons in Energy Levels
Determining Electrons in Energy Levels
Element SymbolAtomic Number
Mass Number
Number of
Protons
Number of
Neutrons
Number of Electrons
Number of Electrons Number of Valence
Electrons1st Level
2nd Level
3rd Level
Hydrogen
Helium
Oxygen
Sodium
Element SymbolAtomic Number
Mass Number
Number of
Protons
Number of
Neutrons
Number of Electrons
Number of Electrons Number of Valence
Electrons1st Level
2nd Level
3rd Level
Hydrogen
Helium
Oxygen
Sodium
Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 21
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Box 1 Element Name Box 2 Element Name
Box 3 Element Name Box 4 Element Name
Models of Atoms
Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 22
Key
Subatomic Particle Color
Electrical Charge
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Gateways to Science, STAAR Edition, Grade 8
Use
the
Per
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to c
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the
tabl
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 23
An
alyz
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Ato
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Str
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Assessment—The Bohr Model and Valence Electrons
Choose the best answer for each question.
1 How many protons are in an atom of magnesium?
A 3
B 12
C 24
D 40
2 How many electrons can the first energy level hold?
F 2
G 4
H 6
J 8
3 How many energy levels are found in Period 2?
A 1
B 2
C 3
D 4
Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 24
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 24 continued
4 Which element has the same number of electrons in the outermost energy level as lithium?
F Hydrogen
G Beryllium
H Carbon
J Magnesium
5 Which element has the same number of energy levels as nitrogen?
A Boron
B Chlorine
C Phosphorus
D Silicon
6 What is the correct model for carbon?
F H
G J
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 24 continued
7 Which of the following is a correct model for nitrogen?
A C
B D
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 24 continued
8 Which element does the above atom model represent?
F Hydrogen
G Helium
H Lithium
J Boron
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Lesson 4: The Bohr Model and Valence ElectronsUNIT 2: Matter and Energy RM 24 continued
9 Which of the following is the correct number of protons, neutrons, and electrons for an atom of phosphorus?
A proton 15
neutrons 15
electrons 15
C proton 15
neutrons 16
electrons 16
B proton 15
neutrons 16
electrons 15
D proton 16
neutrons 15
electrons 15
10 What atom is represented by 35 protons, 45 neutrons, and 35 electrons?
F Mercury
G Bromine
H Rhodium
J Ytterbium
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Pattern Cards
Lesson 5: The Periodic TableUNIT 2: Matter and Energy RM 25
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Lab Station Cards
Lesson 5: The Periodic TableUNIT 2: Matter and Energy RM 26
Station 1
1. Test the electrical conductivity of each element in the bag.
2. Classify each element as a good or poor conductor of electricity.
3. Locate each element on the Periodic Table. Where are the good electrical conductors located?
Station 2
1. Test to find out if the elements in the bag are attracted to a magnet.
2. Classify each element as attracted or not attracted to a magnet.
3. Locate each element on the Periodic Table. Where are the elements that are attracted to the magnet located?
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UNIT 2: Matter and Energy RM 26 continuedLesson 5: The Periodic Table
Station 4
1. Malleability is a physical property that describes matter that can be hammered into thin sheets without breaking.
2. Matter that breaks easily when hammered or struck has the physical property of brittleness. Malleable and brittle are the opposite of each other.
3. Place the carbon charcoal briquette and the aluminum soda can tab on the protective square surface. Cover with the cloth. Hit each object only once.
4. Which object had the property of malleability? Which object had the property of brittleness?
5. Locate each element on the Periodic Table. Where are the malleable elements located? Where are the brittle elements located?
Station 3
1. Luster is a physical property that describes the reflection of light off a surface.
2. Matter that reflects light is said to have a shiny luster. Matter that looks like a metal is said to have a metallic luster. Matter that does not reflect light is said to have a dull luster.
3. Locate each element on the Periodic Table. Where are the elements with the shiny luster located? Where are the elements with a metallic luster located? Where are the elements with the dull luster located?
malleable brittle
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Anticipation Guide—The Periodic Table
Lesson 5: The Periodic TableUNIT 2: Matter and Energy RM 27
Before Learning
StatementsAfter
Learning
A D 1. Metals are located on the right side of the Periodic Table. A D
A D 2. Elements of the same periods have similar properties. A D
A D 3. Elements of the same group have the same number of electrons. A D
A D 4. Valence electrons are located on the outermost energy level. A D
A D 5. Reactivity of an element depends on its number of valence electrons. A D
Anticipation Guide—The Periodic Table
Before Learning
StatementsAfter
Learning
A D 1. Metals are located on the right side of the Periodic Table. A D
A D 2. Elements of the same periods have similar properties. A D
A D 3. Elements of the same group have the same number of electrons. A D
A D 4. Valence electrons are located on the outermost energy level. A D
A D 5. Reactivity of an element depends on its number of valence electrons. A D
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Lesson 5: The Periodic TableP
erio
dic
Tabl
e In
form
atio
n Element Phosphorus
Symbol Mg C Ni
Period 5 3
Group 15 (5A) 17 (7A)
Valence Electrons
8
Element Clue
Per
iodi
c Ta
ble
Info
rmat
ion Element Phosphorus
Symbol Mg C Ni
Period 5 3
Group 15 (5A) 17 (7A)
Valence Electrons
8
Element Clue
Per
iodi
c Ta
ble
Info
rmat
ion Element Phosphorus
Symbol Mg C Ni
Period 5 3
Group 15 (5A) 17 (7A)
Valence Electrons
8
Element Clue
UNIT 2: Matter and Energy RM 28
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Lesson 5: The Periodic Table
Choose the best answer for each question.
1 The number of valence electrons is —
A the number of protons located in the nucleus
B the number of electrons in every energy level
C the total number of protons and neutrons
D the number of electrons in the outermost energy level
2 The part of the atom that has a negative charge is the —
F nucleus
G electron
H neutron
J proton
3 Which of the following has the largest mass in an atom?
A Protons
B Electrons
C Energy levels
D Electron cloud
4 Which of the following properties is determined by the valence electrons?
F color
G malleability
H reactivity
J density
Assessment—The Periodic Table
UNIT 2: Matter and Energy RM 29
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Lesson 5: The Periodic TableUNIT 2: Matter and Energy RM 29 continued
5 Use the Periodic Table to determine the number of protons, electrons, and neutrons in an atom of
potassium.
A 19 protons, 19 neutrons, 19 electrons
B 19 protons, 20 neutrons, 19 electrons
C 39 protons, 19 neutrons, 19 electrons
D 39 protons, 39 neutrons, 39 electrons
6 Which element does this atom represent?
F Hydrogen
G Helium
H Lithium
J Beryllium
7 Which of the following elements have similar chemical properties?
A Nitrogen, oxygen, fluorine
B Silicon, arsenic, astatine
C Fluorine, chlorine, bromine
D Titanium, calcium, mercury
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Lesson 5: The Periodic TableUNIT 2: Matter and Energy RM 29 continued
8 Which element is found in Group 5, Period 4?
F Lithium
G Vanadium
H Zirconium
J Potassium
9 Which of the following elements is malleable?
A Iron
B Hydrogen
C Carbon
D Sulfur
10 Which of the following elements is a metalloid?
F Sulfur
G Iron
H Silicon
J Copper
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Lesson 6: Periodic Table Families
Sisilicon
Hehelium
• gray
• solid
• melting point = 1410 °C
• conducts electricity under some conditions
• used in glass, semiconductors
• four valence electrons
• colorless
• gas
• melting point = –272 °C
• poor conductor of heat and electricity
• used in balloons, deep-sea diving
• reacts with few, if any, elements
• two valence electrons
Lilithium
Beberyllium
• silvery, somewhat lustrous
• soft solid, malleable
• melting point = 180.54 °C
• good conductor of heat and electricity
• reacts strongly with water
• used in batteries, ceramics, lubricants
• one valence electron
• gray, dull
• solid, malleable
• melting point = 1278 °C
• good conductor of heat and electricity
• used in spacecraft, missiles, aircraft, golf clubs
• two valence electrons
Clchlorine
Ccarbon
• green
• gas
• melting point = –100.98 °C
• poor conductor of heat and electricity
• reacts easily with many elements
• used in water purification, bleaches
• seven valence electrons
• dull black solid
• melting point = 3500 °C
• different structural forms vary in conductivity of heat and electricity
• used in steel, filters, can form diamonds, essential to living things
• four valence electrons
Element Cards
UNIT 2: Matter and Energy RM 30
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UNIT 2: Matter and Energy RM 30 continuedLesson 6: Periodic Table Families
Nnitrogen
Ooxygen
• colorless
• gas
• melting point = –209.9 °C
• poor conductor of heat and electricity
• forms most of atmosphere
• five valence electrons
• colorless
• gas
• melting point = –218.4 °C
• poor conductor of heat and electricity
• supports life, supports burning
• reacts with many elements
• six valence electrons
Ffluorine
Neneon
• greenish
• gas
• melting point = –219.62 °C
• poor conductor of heat and electricity
• reacts very easily with many elements
• used in refrigerants
• seven valence electrons
• colorless
• gas
• melting point = –248.6 °C
• poor conductor of heat and electricity
• used in lighting
• reacts with few, if any, elements
• eight valence electrons
Nasodium
Mgmagnesium
• silvery
• soft solid (can be cut with a knife)
• melting point = 97.8 °C
• good conductor of heat and electricity
• highly reactive; actively reactive with water
• used in medicine, agriculture
• one valence electron
• grayish
• solid
• melting point = 650 °C
• good conductor of heat and electricity
• malleable
• reacts with many elements
• used in airplanes, missiles
• two valence electrons
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UNIT 2: Matter and Energy RM 30 continuedLesson 6: Periodic Table Families
Kpotassium
Ninickel
• silvery
• solid
• soft solid (can be cut with a knife)
• melting point = 63.65 °C
• good conductor of heat and electricity
• highly reactive; actively reactive with water
• used in glass, soap
• one valence electron
• silvery tinge, lustrous
• solid
• melting point = 1453 °C
• conducts heat and electricity
• naturally magnetic
• malleable
• used in coinage, stainless steel, electroplating, batteries
Pphosphorus
Ssulfur
• white (can be yellow)
• solid, dull luster
• melting point = 44.1 °C
• poor conductor of heat and electricity
• brittle
• used in fertilizers, detergents
• five valence electrons
• yellow, dull
• solid
• melting point = 112.8 °C
• poor conductor of heat and electricity
• brittle
• found in many minerals
• used in matches, gunpowder, medicines
• six valence electrons
Bboron
Cocobalt
• brownish black
• solid
• melting point = 2300 °C
• conducts electricity under certain conditions
• used in heat-resistant alloys
• three valence electrons
• grayish tinge, lustrous
• solid
• melting point = 1495 °C
• brittle
• naturally magnetic
• conducts heat and electricity
• used in magnets, ceramics, special types of glass
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UNIT 2: Matter and Energy RM 30 continuedLesson 6: Periodic Table Families
Cacalcium
Asarsenic
• silvery solid, malleable
• melting point = 839 °C
• good conductor of heat and electricity
• reacts with many other elements
• used by life forms for bones and shells
• two valence electrons
• gray
• solid
• melting point = 817 °C
• conducts electricity under certain conditions
• used in poison, semiconductors
• five valence electrons
Feiron
Cucopper
• silvery solid, malleable
• melting point = 1535 °C
• good conductor of heat and electricity
• naturally produces magnetic field
• used in steel, found in hemoglobin (carries oxygen in the blood)
• red/orange solid
• melting point = 1083 °C
• good conductor of heat and electricity
• malleable
• electrical conductor
• used in jewelry, coins, plumbing
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UNIT 2: Matter and Energy RM 30 continuedLesson 6: Periodic Table Families
Krkrypton
Agsilver
• colorless
• gas
• melting point = –157.3 °C
• mostly inert; reacts with few, if any, substances
• used in lighting
• poor conductor of heat and electricity
• eight valence electrons
• silver
• solid
• melting point = 961.95 °C
• malleable, ductile
• good conductor of electricity and heat
• used in silverware, jewelry, batteries, mirrors
Brbromine
Hgmercury
• red-brown
• liquid
• melting point = –7 °C
• reacts with many elements
• poor conductor of heat and electricity
• extremely toxic and can cause severe burns
• used in pesticides
• seven valence electrons
• silver
• liquid
• melting point = –38.83 °C
• poisonous
• used in barometers, thermometers, and streetlights
Arargon
Alaluminum
• colorless
• gas
• melting point = 189.3 °C
• extremely unreactive
• used in light bulbs, medical lasers, and double-paned windows
• reacts with very few, if any, elements
• poor conductor of heat and electricity
• eight valence electrons
• solid
• silvery-white
• melting point = 660.32 °C
• malleable, ductile
• excellent conductor of electricity and heat
• used in cans, cooking pots, window frames, boats, aircraft
• three valence electrons
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UNIT 2: Matter and Energy RM 30 continuedLesson 6: Periodic Table Families
Rbrubidium
Srstrontium
• silvery-white
• solid
• melting point = 39.3 °C
• good conductor of heat and electricity
• reactive with other elements
• reacts violently with water
• used in photocells
• one valence electron
• solid
• silvery
• melting point = 1280 °C
• conducts heat and electricity
• chemically reactive
• used in cathode ray tubes for TVs, atomic clocks
• two valance electrons
Augold
Sntin
• gold
• solid
• melting point = 1064.18 °C
• excellent conductor of heat and electricity
• malleable, ductile
• used in jewelry, coins, dental work
• silvery-white
• solid
• melting point = 231.93 °C
• good conductor of heat and electricity
• found in some toothpastes
Seselenium
Iiodine
• gray, red, or black
• solid
• melting point = 220 °C
• used in photo cells, light sensors, and photocopying machines
• conductivity varies
• six valence electrons
• bluish-black
• solid
• melting point = 113.5 °C
• reacts with many elements
• used in medicines, disinfectants
• seven valence electrons
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Lesson 6: Periodic Table Families
Find Someone Who . . .
UNIT 2: Matter and Energy RM 31
Find someone who knows the answer to each statement. You may only let one student answer one question. Don’t forget to use the Periodic Table.
1. Find someone who knows the element found in Group 2, Period 2.
2. Find someone who can give an example of a chemical property.
3. Find someone who knows the element found in Period 4 with 6 valence electrons.
4. Find someone who can name a metal in Group 14.
5. Find someone who can name a nonmetal in Group 16.
6. Find someone who can name the noble gas in Period 5.
7. Find someone who can name an element found in Group 1.
8. Find someone who can name the number of valence electrons for carbon.
9. Find someone who can name a metal with 5 valence electrons.
10. Find someone who can name a characteristic of groups.
11. Find someone who can list three things that can be determined using the Periodic Table.
12. Find someone who can define the word malleable.
13. Find someone who knows how many valence electrons are needed for a stable atom arrangement.
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Understanding Valence Electrons
Lesson 6: Periodic Table FamiliesUNIT 2: Matter and Energy RM 32
The models in the table below show various atoms in which the center black circle represents the nucleus and the rings represent energy levels. Electrons are shown only on the outermost energy level of each model. Use the Periodic Table of Elements to provide the missing information.
Model ElementNumber of
Valence Electrons
Period Number Group Number
Metal, Metalloid,
Nonmetal, or Noble Gas
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Lesson 6: Periodic Table FamiliesUNIT 2: Matter and Energy RM 32 continued
Model ElementNumber of
Valence Electrons
Period Number Group Number
Metal, Metalloid,
Nonmetal, or Noble Gas
Interpreting Data and Drawing Conclusions
1. Which of the eight elements in the table is least likely to gain or lose electrons? Why?
2. Which of the eight elements is most likely to lose only one electron? Why?
3. Which of the eight elements is most likely to gain only one electron? Why?
4. Explain why all eight of the elements in the table are located on the same horizontal row of the Periodic Table.
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Lesson 6: Periodic Table Families
Per
iod
ic T
able
of
the
Ele
men
ts C
on
cep
t M
apUNIT 2: Matter and Energy RM 33
Pat
tern
sB
lock
sA
rran
gem
ent
Per
iod
ic T
able
of
the
Ele
men
ts
prop
ertie
spr
oper
ties
sam
e nu
mbe
r of
sam
e nu
mbe
r of
num
ber
of
prot
ons
+nu
mbe
r of
alon
gzi
gzag
that
lose
to fo
rm
onle
ft si
de
that
gai
n
to fo
rm
onrig
ht s
ide
has
top
num
ber
calle
dha
s bo
ttom
num
ber
calle
dho
rizon
tal
row
s ar
e
with
with
vert
ical
colu
mns
are
WO
RD
BA
NK
atom
ic n
umbe
rdi
ssim
ilar
elec
tron
sen
ergy
leve
lsgr
oups
mas
s nu
mbe
rm
etal
sm
etal
loid
sne
gativ
e io
ns
neut
rons
nonm
etal
spe
riods
posi
tive
ions
prot
ons
reac
tivity
sim
ilar
vale
nce
elec
tron
s
and
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Choose the best answer for each question.
1 Which of the following elements is the most reactive nonmetal?
A Sodium
B Helium
C Chlorine
D Tin
2 Which of the following elements is least likely to react with another substance?
F Sodium
G Helium
H Chlorine
J Tin
3 Which subatomic particle defines the identity of an element?
A Nucleus
B Electron
C Neutron
D Proton
4 Which element is found in Group 1, Period 2?
F Lithium
G Vanadium
H Zirconium
J Potassium
Lesson 6: Periodic Table Families
Assessment—Periodic Table Families
UNIT 2: Matter and Energy RM 34
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UNIT 2: Matter and Energy RM 34 continuedLesson 6: Periodic Table Families
5 Which of the following elements is found in Group 2?
A Boron
B Helium
C Calcium
D Lithium
6 Which statement best describes the elements in Group 2?
F All elements have 2 energy levels.
G All elements have 2 valence electrons and are gases.
H All elements have 2 valence electrons and are metals.
J All elements have 2 valence electrons and are nonmetals.
7 Which of the following statements best describes reactivity of elements?
A Elements that contain 1 or 7 valence electrons are very reactive.
B Groups 3 through 12 are considered nonreactive, or inert.
C All elements on the Periodic Table have the same reactivity.
D The reactivity of elements is considered a physical property.
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Structure of Matter Concept Map
Lesson 7: Compounds and Chemical FormulasUNIT 2: Matter and Energy RM 35
which have a positive charge
which have a negative charge
which have no charge
make up
of the sametype are
sugar water
salt water NaOH
CH4
NaCl I2
NaCI
O2
which physically mix to form which chemically combine to form
WORD BANKatomscompoundselectronselementsmixturesmolecules neutronsprotons
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Paper Models
UNIT 2: Matter and Energy RM 36Lesson 7: Compounds and Chemical Formulas
O
6 valenceelectrons
O
6 valenceelectrons
O
6 valenceelectrons
O
6 valenceelectrons
O
6 valenceelectrons
O
6 valenceelectrons
Ca
2 valenceelectrons
Ca
2 valenceelectrons
Na
1 valenceelectron
CI
7 valenceelectrons
CI
7 valenceelectrons
CI
7 valenceelectrons
AI
3 valenceelectrons
AI
3 valenceelectrons
C
4 valenceelectrons
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1. magnesium sulfate = 1 atom of magnesium + 1 atom of sulfur + 4 atoms of oxygen
2. potassium chloride = 1 atom of potassium + 1 atom of chlorine
3. glucose = 6 atoms of carbon + 12 atoms of hydrogen + 6 atoms of oxygen
4. baking soda =1 atom of sodium + 1 atom of hydrogen + 1 atom of carbon + 3 atoms of oxygen
Practice—Writing Chemical Formulas
UNIT 2: Matter and Energy RM 37Lesson 7: Compounds and Chemical Formulas
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1. carbon dioxide = 1 atom of carbon + 2 atoms of oxygen
2. calcium carbonate = 1 atom of calcium + 1 atom of carbon + 3 atoms of oxygen
3. sulfuric acid = 2 atoms of hydrogen + 1 atom of sulfur + 4 atoms of oxygen
4. hydrogen peroxide = 2 atoms of hydrogen + 2 atoms of oxygen
5. hydrochloric acid = 1 atom of hydrogen + 1 atom of chlorine
Writing Chemical Formulas
UNIT 2: Matter and Energy RM 38Lesson 7: Compounds and Chemical Formulas
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Choose the best answer for each question.
1 Which of these does not belong in the group?
A Lead
B Water
C Hydrogen
D Element
2 All of these are examples of compounds except —
F H2
G NaCl
H H2O
J PbS
3 Molecules that are made of only one kind of atom are —
A mixtures
B compounds
C ions
D elements
Assessment—Compounds and Chemical Formulas
UNIT 2: Matter and Energy RM 39Lesson 7: Compounds and Chemical Formulas
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Lesson 7: Compounds and Chemical Formulas
Page 2 of 2
UNIT 2: Matter and Energy RM 39 continued
4 Which of these elements is least likely to form a compound?
F Sodium
G Helium
H Hydrogen
J Aluminum
5 What is the correct chemical formula for a compound that contains 2 atoms of sodium, 1 atom of sulfur, and 4 atoms of oxygen?
A NA2SO4
B Na2S1O4
C Na2SO4
D na2S1O4
6 Which of the following tables correctly identifies the substance listed?
F Pb Element
O2Molecule
CaSO4Element
H2O Molecule
H Pb Element
O2Molecule
CaSO4Compound
H2O Molecule
G Pb Molecule
O2Element
CaSO4Compound
H2O Molecule
J Pb Compound
O2Element
CaSO4Molecule
H2O Compound
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Matching Cards
UNIT 2: Matter and Energy RM 40Lesson 8: Analyzing Chemical Formulas
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NaCl CH4
Fe2O3 H2SO4
HCl Mg(OH)2
Practice—Determining Atoms
UNIT 2: Matter and Energy RM 41Lesson 8: Analyzing Chemical Formulas
Pb
O
O
O
N
N
N
C
O
O
OCa
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1. bromine—Br2
2. calcium chloride—CaCl2
3. potassium iodide—KI
4. benzene—C6H6
5. beryllium hydroxide—Be(OH)2
6. copper carbonate—CuCO3
7. magnesium nitrate—Mg(NO3)2
8. magnesium hydroxide—Mg(OH)2
9. silver oxide—Ag2O
10. ammonium hydroxide—NH4OH
11. sodium carbonate—Na2CO3
12. calcium nitrite —Ca(NO2)2
Additional Practice
UNIT 2: Matter and Energy RM 42Lesson 8: Analyzing Chemical Formulas
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Using Coefficients
UNIT 2: Matter and Energy RM 43
6H2O
3CaCl2
Coefficient —There are 6 molecules of water.
Lesson 8: Analyzing Chemical Formulas
Subscript—There are 2 atoms of hydrogen.
No subscript—There is only 1 atom of oxygen.
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Chemical Formulas
UNIT 2: Matter and Energy RM 44
1. HO
2. HO
3. CHCl
4. 3CO2
5. 2CaSO3
6. 2 Ca(OH)2
Lesson 8: Analyzing Chemical Formulas
H HO O
H H
O
H H
O
H H
O
C Cl
H
H
H C Cl
H
H
H
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Mo
del
Nam
eE
lem
ent,
Mo
lecu
le,
Co
mp
ou
nd
Fo
rmu
laTo
tal N
um
ber
o
f E
lem
ents
Nam
es o
f E
lem
ents
Nu
mb
er
of
Ato
ms
of
Eac
h
Ele
men
t
HH
Ow
ater
H2O
HO
Na
sodi
um
hydr
oxid
e
Na
1 va
lenc
eel
ectr
on
CI
7 va
lenc
eel
ectr
ons
sodi
um
chlo
ride
(sal
t)N
aCI
Ca
2 va
lenc
eel
ectr
ons
CI
7 va
lenc
eel
ectr
ons
CI
7 va
lenc
eel
ectr
ons
calc
ium
ch
lorid
e
Mg
2 va
lenc
eel
ectr
ons
O
6 va
lenc
eel
ectr
ons
mag
nesi
um
oxid
e
UNIT 2: Matter and Energy RM 45
Composition of Compounds
Lesson 8: Analyzing Chemical Formulas
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Choose the best answer for each question.
1 Which element is found in all of these compounds?
C2H6 NaHCO3 C6H12O6 CO2
A Oxygen
B Sodium
C Hydrogen
D Carbon
2 How many atoms of carbon are found in glucose, C6H12O6?
F 3
G 6
H 12
J 24
3 A molecule that contains two or more elements is called —
A an atom
B a mixture
C an ion
D a compound
Assessment—Analyzing Chemical Formulas
UNIT 2: Matter and Energy RM 46Lesson 8: Analyzing Chemical Formulas
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UNIT 2: Matter and Energy RM 46 continued
4 How many elements are found in CuSO4?
F 3
G 4
H 5
J 6
5 Which of the models best represents CaCO3?
A
C
O
O
OCa
C
C O
Ca
B
C O
O
Ca
D
C
C
C
O
Ca
Lesson 8: Analyzing Chemical Formulas
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UNIT 2: Matter and Energy RM 47
Models of Matter
1. In your science notebook, draw the model shown above and create a table similar to the one below. Use
your knowledge about atoms to complete the table.
Symbol Name of Subatomic Particle Electrical Charge (+ or –) Inside or Outside the Nucleus
2. Does the model represent an atom, a molecule, or both?
3. Does the model represent an element or a compound?
4. What are the names of the elements shown in the model?
5. What is the chemical formula for the substance?
6. What substance does the model represent?
Lesson 9: Chemical Changes in Compounds
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Station 1
1. Put on your safety goggles.
2. Place 20 drops of ammonia in a test tube. Add 20 drops of purple grape juice.
3. Observe any changes that occur.
4. Discuss and record your observations.
5. Record a statement that summarizes the results of this station.
6. Dispose of materials according to your teacher’s directions.
7. Leave your station clean, dry, and organized.
Station 2
1. Put on your safety goggles.
2. Observe and record the physical properties of the citric acid and baking soda.
3. Place a small scoop of citric acid and baking soda in the small resealable plastic bag.
4. Add 10 mL of water. Seal the plastic bag.
5. Observe any changes that occur.
6. Discuss and record your observations. How have the properties changed?
7. Record a statement that summarizes the results of this station.
8. Dispose of your materials according to your teacher’s instructions.
9. Leave your station clean, dry, and organized.
Lab Station Cards
UNIT 2: Matter and Energy RM 48Lesson 9: Chemical Changes in Compounds
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UNIT 2: Matter and Energy RM 48 continued
Station 3
1. Put on your safety goggles.
2. Observe and record the physical properties of calcium chloride.
3. Place 1 spoonful of calcium chloride in a small paper cup.
4. Add 25 mL of water. Stir well with a craft stick.
5. Observe any changes that occur.
6. Discuss and record your observations.
7. Record a statement that summarizes the results of this station.
8. Dispose of your materials according to your teacher’s instructions.
9. Leave your station clean, dry, and organized.
Station 4
1. Put on your safety goggles.
2. Observe and record the physical properties of the milk and vinegar.
3. Place 10 mL of milk into the small resealable plastic bag.
4. Add 10 mL of vinegar to the bag. Seal the bag.
5. Observe any changes that occur. How have the properties changed?
6. Discuss and record your observations.
7. Record a statement that summarizes the results of this station.
8. Dispose of the plastic bag and its contents in the trash.
9. Leave your station clean, dry, and organized.
Lesson 9: Chemical Changes in Compounds
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Frayer Model
Frayer Model
UNIT 2: Matter and Energy RM 49Lesson 9: Chemical Changes in Compounds
Definition
Example
Characteristics
Nonexample
Definition
Example
Characteristics
Nonexample
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A chemical reaction is another name for a chemical change.
• Evidence of a chemical reaction
• formation of gas, causing bubbling, fizzing, or foaming
• changes in temperature,
• production of light, smoke, sound, or new odor
• changes in color
• production of a precipitate
Chemical equations represent chemical reactions.
• Reactants are the starting materials.
• Products are the ending materials.
2H2 + O2 2H2O
Reactants Yields Products
1 3NaHCO3 + C6H8O7 C6H5Na3O7 + 3CO2 + 3H2O sodium + citric yields sodium + carbon + water
bicarbonate acid citrate dioxide
2 CaCl2 + H2O CaO + 2HCl calcium + water yields calcium oxide hydrochloric acid chloride
UNIT 2: Matter and Energy RM 50
Discussion Points
Lesson 9: Chemical Changes in Compounds
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1. Emerson is excited because she is going to combine several substances in her science class today. Emerson’s teacher directs the class to combine calcium (Ca) with hydrochloric acid (HCl). Emerson notices that a temperature change occurs and a gas is produced after she combines the two substances. Her teacher tells the class that calcium chloride (CaCl2) and hydrogen gas (H2) are produced in this chemical reaction.
2. Jose leaves his skateboard outside for several days. When he goes to ride it, he notices there is a brownish-red colored material that rubs off on his fingers. His mother tells him that the brownish-red material is rust, or iron oxide (Fe2O3). Iron oxide forms when iron (Fe) is exposed to oxygen (O2).
3. Max wants to model a volcanic eruption for his school project. He combines baking soda (NaHCO3) and vinegar (HC2H3O2) to create the eruption. Not only does Max get an A on his project, but he also forms sodium acetate (NaC2H3O2), water (H2O), and carbon dioxide (CO2) in the simulated eruption.
Chemical Storytelling
UNIT 2: Matter and Energy RM 51Lesson 9: Chemical Changes in Compounds
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Parts of a Chemical Equation
UNIT 2: Matter and Energy RM 52Lesson 10: Chemical Equations
Chemical Symbol
Yields
Coefficient
Subscript Coefficient
Chemical Formula
2H2 + O2 2H2O
Fe + 2HCI FeCI2 + H2
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Circle the reactants, draw a box around the products, draw an asterisk (*) above the coefficients, and underline the subscripts.
1 CaCl2 + F2 CaF2 + Cl2
calcium chloride fluorine yields calcium fluoride chlorine
2 4Al + 3O2 2AI2O3
aluminum oxygen yields aluminum oxide
3 CH4 + 2O2 CO2 + 2H2O
methane oxygen yields carbon dioxide water
UNIT 2: Matter and Energy RM 53
Name That Part!
Lesson 10: Chemical Equations
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Practice—Models of Chemical Equations
Reactants Products
Word Equation
2 atoms of copper
reacts with1 molecule of oxygen
to yield 1 molecule of copper oxide
Chemical Equation
2Cu + O22CuO
Visual Model +
Number of Atoms
Reactants Products
Word Equation
1 molecule of calcium chloride
reacts with1 molecule of fluorine
to yield1 molecule of calcium
fluorideand
1 molecule of chlorine
Chemical Equation CaCl2 + F2 CaF2
+ Cl2
Visual Model + +
Number of Atoms
Lesson 10: Chemical EquationsUNIT 2: Matter and Energy RM 54
Page 1 of 2
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UNIT 2: Matter and Energy RM 54 continuedLesson 10: Chemical Equations
Practice—Models of Chemical Equations Answer Key
Reactants Products
Word Equation
2 atoms of copper
reacts with1 molecule of oxygen
to yield 1 molecule of copper oxide
Chemical Equation
2Cu + O22CuO
Visual Model +
Number of Atoms
2 copper 2 oxygen 2 copper 2 oxygen
Reactants Products
Word Equation
1 molecule of calcium chloride
reacts with1 molecule of fluorine
to yield1 molecule of calcium
fluorideand
1 molecule of chlorine
Chemical Equation CaCl2 + F2 CaF2
+ Cl2
Visual Model + +
Number of Atoms
1 calcium 2 flourine 2 chlorine
1 calcium 2 chlorine 2 flourine
Cu
CuO O
Cu
Cu
O
O
F
F
F
F
Cl
Cl
Cl ClCa Ca
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UNIT 2: Matter and Energy RM 55
Models of Chemical Reactions and Equations
Lesson 10: Chemical Equations
Complete each of the tables by drawing a visual model and identifying the number of atoms for each reaction.
Reactants Products
Word Equation
1 molecule of sodium hydroxide
reacts with1 molecule hydrochloric
acidto yield
1 molecule of sodium chloride
and1 molecule
of water
Chemical Equation
NaOH + HCI NaCI + H2O
Visual Model + +
Number of Atoms
Reactants Products
Word Equation
2 molecules of hydrogen peroxide
to yield2 molecules
of waterand
1 molecule of oxygen
gas
Chemical Equation 2H2O2
2H2O + O2
Visual Model
Number of Atoms
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UNIT 2: Matter and Energy RM 55 continuedLesson 10: Chemical Equations
Reactants Products
Word Equation
1 atom of iron
reacts with2 molecules hydrochloric
acidto yield
1 molecule of iron
chlorideand
1 molecule of hydrogen
gas
Chemical Equation
Fe + 2HCI FeCl2 + H2
Visual Model
Number of Atoms
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Lesson 10: Chemical EquationsUNIT 2: Matter and Energy RM 55 continued
Models of Chemical Reactions and Equations—Answer Key
Complete each of the tables by drawing a visual model and identifying the number of atoms for each reaction.
Reactants Products
Word Equation
1 molecule of sodium hydroxide
reacts with1 molecule hydrochloric
acidto yield
1 molecule of sodium chloride
and1 molecule
of water
Chemical Equation
NaOH + HCI NaCI + H2O
Visual Model + +
Number of Atoms
1 oxygen1 hydrogen
1 chlorine1 hydrogen
1 sodium1 chlorine
1 oxygen2 hydrogen
Reactants Products
Word Equation
2 molecules of hydrogen peroxide
to yield2 molecules
of waterand
1 molecule of oxygen
gas
Chemical Equation 2H2O2
2H2O + O2
Visual Model +
Number of Atoms
4 hydrogen4 oxygen
4 hydrogen4 oxygen
Na NaO O
O
O O
O
O
O
O
O
H H
H
H
H
H
H
H
H
H
H
H
Cl Cl
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Lesson 10: Chemical EquationsUNIT 2: Matter and Energy RM 55 continued
Reactants Products
Word Equation
1 atom of iron
reacts with2 molecules hydrochloric
acidto yield
1 molecule of iron
chlorideand
1 molecule of hydrogen
gas
Chemical Equation
Fe + 2HCI FeCl2 + H2
Visual Model + +
Number of Atoms
1 iron2 hydrogen
2 chlorine1 iron2 chlorine
2 hydrogen
FeFe
Cl
Cl
Cl
Cl
H
H
H H
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Choose the best answer for each question.
1 All of these are examples of elements except —
A Cu
B KI
C He
D H
2 A chemical formula shows all of the following except —
F the number of atoms of each element
G the chemical symbols of elements
H the elements found in a compound
J the number of protons in a nucleus
3 All of these are examples of the chemical formula of a compound except —
A H2
B MgO
C SiO2
D H2O
4 What is the appropriate subscript for oxygen in the models shown?
F 1
G 2
H 3
J 6
Assessment—Chemical Equations
UNIT 2: Matter and Energy RM 56Lesson 10: Chemical Equations
CO
O
O
Na
NaCO
O
O
Na
Na
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UNIT 2: Matter and Energy RM 56 continued
5 How many total atoms are in the compound CuSO4?
A 3
B 4
C 5
D 6
6 How many elements are in 2H2SO4?
F 2
G 3
H 7
J 14
7 How many molecules are found in this formula 2LI3PO4?
A 2
B 3
C 4
D 16
8 How many atoms of carbon are found in glucose, C6H12O6?
F 3
G 6
H 12
J 24
Lesson 10: Chemical Equations
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UNIT 2: Matter and Energy RM 56 continued
Use the following formula to answer questions 9 and 10.
2Na + CI2 2NaCI sodium chloride
9 In the above reaction, what are the reactants?
A Sodium, carbon, and iodine
B Sodium and chlorine
C Sodium chloride
D Sodium, chlorine, and sodium chloride
10 In the above reaction, what is the product?
F Na, C, and I
G Na, Cl
H NaCl
J Na, Cl, and NaCl
11 In the chemical equation, the elements are rearranged to form new products. Which of the following compounds should be placed in the box?
C + O2 ??
A CO2
B H2O
C Co
D CaCl2
Lesson 10: Chemical Equations
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UNIT 2: Matter and Energy RM 56 continuedLesson 10: Chemical Equations
12 Which two compounds contain the same total number of atoms?
F C3H8 and C2H6
G NO2 and KCl
H 2Li2S and BeCl2
J 2CO and CO2
13 Which of the following is an example of a chemical change?
A Water evaporating
B Tearing paper into smaller pieces
C Combining baking soda and vinegar
D Mixing water and sugar
14 All of the following are indicators of a chemical change except —
F formation of a gas
G change in temperature
H change in the state of matter
J formation of a precipitate
15 Chemical equations tell a story of a chemical change where the elements are rearranged, forming new substances. All of the following chemical equations indicate a chemical reaction except —
A Fe + Cl2 FeCl2
B 3Mg + N2 Mg3N2
C 2Ag + H2S H2O + Pb
D 4 Fe + 3O2 2Fe2O3
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Group Lab Activity Cards
UNIT 2: Matter and Energy RM 57
Group Lab Activity 1
Procedures
1. Put on your safety goggles.
2. Use your science notebook to record observations and answer questions.
3. Measure 1 level spoonful of baking soda and place in the resealable plastic bag. Record the physical properties of the baking soda.
4. Use the graduated cylinder to measure 10 mL of vinegar. Pour the vinegar into the small cup. Record the physical properties of the vinegar.
5. Measure 5 mL of purple cabbage juice. Record the physical properties of the purple cabbage juice.
6. Add the purple cabbage juice to the vinegar in the small cup. Record your observations.
7. Carefully place the cup of liquids into the plastic bag without spilling.
8. Close the plastic bag, removing any excess air.
9. Find and record the total mass of the system using a balance. Do not move the riders back to zero.
10. Gently tilt the cup to combine the vinegar with the baking soda. Record your observations.
11. Place the system back on the balance and compare the position of the balance pointer to see if a change in mass occurs.
12. After the reaction stops, find and record the final mass of the system. Record your observations.
13. Answer the following questions.
a. Does a chemical change occur? What evidence do you have?
b. How are the properties of the products different from those of the reactants?
c. What do you notice about the mass of the system before and after combining the two substances?
Lesson 11: Law of Conservation of Mass
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UNIT 2: Matter and Energy RM 57 continued
Group Lab Activity 2
Remember to waft when smelling chemicals.
Procedures
1. Put on your safety goggles.
2. Use your science notebook to record observations and answer questions.
3. Measure 150 mL of water and pour into a 250 mL beaker.
4. Add 1 teaspoon of alum to the water. Stir until completely dissolved. Observe and record the physical properties of the solution.
5. Measure 10 mL of ammonia in a graduated cylinder. Observe and record the physical properties of the ammonia.
6. Place the beaker with the alum solution and the graduated cylinder with the ammonia on a balance. Find the total mass of this system. Do not move the rider back to zero. Record the mass.
7. Slowly pour the ammonia into the alum solution. Do not stir. Record your observations.
8. Place the graduated cylinder and the beaker with its contents back on the balance and compare the position of the balance pointer to see if a change in mass occurs.
9. Find the total mass of the system again. Record the mass.
10. Answer the following questions.
a. Does a chemical change occur? What evidence do you have?
b. How are the properties of the products different from those of the reactants?
c. What do you notice about the mass of the system before and after combining the two substances?
Lesson 11: Law of Conservation of Mass
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Reactants
Teacher Demonstration Cards
UNIT 2: Matter and Energy RM 58Lesson 11: Law of Conservation of Mass
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Gateways to Science, STAAR Edition, Grade 8 Page 2 of 3
UNIT 2: Matter and Energy RM 58 continued
Products
Lesson 11: Law of Conservation of Mass
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Gateways to Science, STAAR Edition, Grade 8 Page 3 of 3
UNIT 2: Matter and Energy RM 58 continuedLesson 11: Law of Conservation of Mass
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Gateways to Science, STAAR Edition, Grade 8
Discussion Points
UNIT 2: Matter and Energy RM 59Lesson 11: Law of Conservation of Mass
The Law of Conservation of Mass
Matter cannot be created or destroyed.
The number of atoms of each element in the reactants and the number of atoms of each
element in the products must be equal.
reactantsyield
products
total number of atoms of each element
=equals
total number of atoms of each element
mass of reactants=
equalsmass of products
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Gateways to Science, STAAR Edition, Grade 8 Page 1 of 2
ERP
UNIT 2: Matter and Energy RM 60Lesson 11: Law of Conservation of Mass
C + O2 CO2
C + O O OO C
reactants product
Elements Found in Equation
Reactant Atoms
(number of)
Product Atoms
(number of)
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UNIT 2: Matter and Energy RM 60 continuedLesson 11: Law of Conservation of Mass
NaOHsodium hydroxide
+ HClhydrochloric acid
NaClsodium chloride
+ H2Owater
Na O H + ClH Na Cl + OHH
Elements Found in Equation
Reactant Atoms
(number of)
Product Atoms
(number of)
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Gateways to Science, STAAR Edition, Grade 8
1. C + O2 CO2
2. 6C + 6H2O C6H12O6
3. Na + Cl2 NaCl
4. CH4 + O2 CO2 + 2H2O
5. CO2 + H2O H2CO3
6. 2HCl + CaCO3 CaCl2 + CO2 + H2O
The Law of Conservation of Mass
UNIT 2: Matter and Energy RM 61Lesson 11: Law of Conservation of Mass
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Gateways to Science, STAAR Edition, Grade 8
1. 2KI + Cl2 2KCl + I2
2. 2N2 + O2 2N2O
3. H2O2 H2O + O2
4. 2C2H6 + O2 4CO2 + 3H2O
5. 2KClO3 2KCl + 3O2
6. Mg + 2HCl MgCl2 + H2
7. SO3 + H2O H2SO4
8. 2HCl + Ca(OH)2 CaCl2 + 2H2O
Additional Reactions
UNIT 2: Matter and Energy RM 62Lesson 11: Law of Conservation of Mass
Recommended