Name:
Unit 2: Chemistry
Period:
Day 8 – Chemistry Unit Exam
Formulas:
 Density = mass/volume
 Atomic # = # of protons OR electrons
 Atomic Mass = # of protons + # of
neutrons
Date:
Reminders
 You will have roughly 55 minutes to finish
 Show strategies and justification for answers
You have worked hard. You know this.
8.5A – Atomic Structure
1) A student makes a drawing of a carbon atom.
Which of these should the student show in the
nucleus of the atom?
a. Ions
b. Protons
c. Electrons
d. Molecules
3) Which of the following is found farthest from
the center of an atom?
a. Nucleus
b. Proton
c. Neutron
d. Electron
2) Which of the following best describes an
atom?
a. Protons and electrons grouped together in
a random pattern
b. Protons and electrons grouped together in
an alternating pattern
c. A core of protons and neutrons
surrounded by electrons
d. A core of electrons and neutrons
surrounded by protons
4) How is the actual atom different from the
Bohr atomic model?
a. The masses of the atomic particles are
different.
b. The numbers of electrons are different.
c. The shapes of the nuclei are different.
d. The electrons are not orbiting in circles,
but rather a cloud.
8
5) The element oxygen is shown to the right. Correctly identify the number of
Protons, Neutrons, and Electrons in a typical oxygen atom.
O
Oxygen
15.999
8.5B – Identity + Reactivity
6) The diagram to the right represents a Bohr Model of an element. Using
the periodic table, as well as your knowledge of atoms, what is the name of
this element?
a.
b.
c.
d.
Argon
Neon
Chlorine
Fluorine
7) Using the diagram to the left, how many
valence electrons does the atom have?
a.
b.
c.
d.
2
3
4
5
9) What is the number of electrons in a
completely filled second shell of an atom?
a.
b.
c.
d.
32
18
8
2
8) The diagram above displays the Alkali Metals
(Group 1) from the Periodic Table. These metals are
so reactive that they can even catch fire in water.
Why are Alkali Metals so reactive?
a.
b.
c.
d.
They want to lose their one valence electron
They want to gain 7 more electrons
They have a full outer shell
They want to lose their two valence electrons
10) Chlorine has 7 valence electrons in its outer
shell. Because of this, chlorine’s reactivity would
be best described as ___________________.
a.
b.
c.
d.
Very reactive
Somewhat reactive
Nonreactive
Neutral
8.5C – Periodic Table
11) Identify one element that has chemical properties similar to the chemical properties of fluorine.
Write your answer in the box for #11 on your answer sheet.
12) Which of the following elements has
properties most similar to Gold (Au)?
a.
b.
c.
d.
Zinc (Zn)
Mercury (Hg)
Silver (Ag)
Cadmium (Cd)
13) Danny is completing a research project
for Mr. Goel’s class on the Periodic Table. He
makes the following list of characteristics
about the elements in the group to the
right:
 In group #17
 # of Valence Electrons = 7
 Often used in cleaning and sanitation
products
Which of the following choices would best
represent the reactivity of the elements in
this family?
a. Reactive
b. Highly reactive
c. Somewhat reactive
d. Nonreactive
14) What is true about elements P, Q, R, and S?
a. They are in the same period
b. They are in the same group
c. They are all nonmetals
d. They are all gases
15) Group #18 on the periodic table consists of
elements that are non-reactive, meaning that
they do not bond or create chemical reactions
with any other elements. Which family name
is attributed to Group #18?
a.
b.
c.
d.
Alkali Metals
Alkaline Earth Metals
Halogens
Noble Gases
6.6A – Metals, Nonmetals, Metalloids
16) Which of the following elements would be
considered a metalloid?
a.
b.
c.
d.
Zinc
Iron
Sulfur
Carbon
17) What is a common physical property of Fe,
Co, Ni, Cu, and Zn?
a.
b.
c.
d.
They are all malleable
They are poor conductors
They react easily with gases
They are brittle
18) What do the elements sulfur (S), nitrogen (N), phosphorus (P), and bromine (Br) have in common?
a.
b.
c.
d.
They are noble (inert) gases
They are nonmetals
They have the same thermal conductivity
They have the same number of protons
19) The diagram shows a simplified periodic
table. Each of the number blocks represents an
element. Which element easily conducts
electricity and can be bent or hammered into a
new shape (malleable)?
a) Element 1
b) Element 2
c) Element 3
d) Element 4
8.5D – Chemical Formulas
20) The diagram below shows the
arrangement of atoms and the chemical
composition of a water molecule. The table
shows common elements and their chemical
symbols.
What two elements make up the water
molecule?
Write your answer in box #20 on your answer
sheet.
Use the following chemical formula for Glucose in questions 21 and 22
C6H12O6
21) How many elements are in a molecule of
glucose?
a.
b.
c.
d.
22) How many atoms are in a molecule of glucose?
a.
b.
c.
d.
3
4
24
26
3
4
24
26
23) How do you determine the number of silicon atoms in the formula below?
4SiO2
a.
b.
c.
d.
# of Si atoms
# of Si atoms
# of Si atoms
# of Si atoms
=
=
=
=
coefficient 4
coefficient 4
subscript 4
coefficient 1
+
X
X
+
subscript 1
subscript 1
coefficient 2
subscript 1
=
=
=
=
5
4
6
2
7.6A + 6.5C – Organic Compounds + Elements vs. Compounds
24) Carbon dioxide (CO2) is not found on the
Periodic Table of the Elements because carbon
dioxide is
a.
b.
c.
d.
An atom
A gas
A mixture
A compound
25) Which of the following compounds would be
considered organic?
a.
b.
c.
d.
C6H12O6
CO2
H2O
NH4
The table below shows the number of each kind of atom that makes up one molecule of the compounds
sucrose and ethanol.
26) Which of the following is the same for both compounds?
a. The mass of each molecule
b. The length of each molecule
c. The types of atoms of elements in each molecule
d. The number of atoms of elements in each molecule
27) Which of the following is the best example of compounds of only one kind?
a.
c.
b.
d.
28) Some common substances and their chemical formulas are listed in
the chart to the right.
Which of these substances are elements?
a. hydrochloric acid and carbonic acid
b. carbon dioxide and water
c. oxygen and helium
d. water and oxygen
8.5E – Chemical Changes
29) The diagram to the right shows what happens when crushed limestone
(like chalk) is placed in acid.
List one observation that shows a chemical change is occurring in the
diagram.
Write your answer in box #31 on your answer document.
30) Which action forms a different chemical substance?
a.
b.
c.
d.
crushing a rock
burning a piece of wood
mixing salt and pepper
melting an ice cube
31) Hydrochloric acid is added to a beaker
containing a piece of zinc. As a result, zinc
chloride is formed and hydrogen gas is released.
This is an example of
a. a chemical reaction
b. a physical change
c. photosynthesis
d. evaporation
(4) on the bottom of the beaker
27 The four diagrams below model the results of
mixing atoms of different substances. Each
atom is represented by a different symbol.
32) The diagram to the right shows an activity performed byWhich diagram correctly models a chemical
a student. What kind of change would this best represent? change?
a. Chemical change, because gas is released
b. Chemical change, because a new substance is created
)
c. Physical change, because the melting ice indicates a (1
phase change
d. Physical change, because there is a temperature
increase
+
+
(2
) different substances. Each atom is
33) The four diagrams below model the results of mixing atoms
of
represented by a different symbol. Which diagram correctly models a chemical change?
a.
c.
(3
)
b.
+
d.
(4
)
+
I nter.-Level Science — June ’01
8.5F – Law of Conservation of Matter
34) Which of the following is the best description of the Law of Conservation of Matter?
a. Matter cannot be created or destroyed, only transformed
b. Matter can be created and destroyed, not transformed
c. Matter can be created, but not destroyed or transformed
d. Matter cannot be created, but can be destroyed and transformed
35) Which chemical equation is balanced to show that mass is conserved during the reaction?
a.
2Na + Cl2 → 4NaCl
c.
CH4 + 2O2 → CO2 + 2H2O
b.
2H2O2 → 4H2O + O2
d.
AgNO3 + MgCl2 → 2AgCl + MgNO3
[8]
The following equation shows photosynthesis in plants.
6CO2 + 6H2O  C6H12O6 + 6CO2
36) Is the equation seen above balanced? Circle YES or NO on your answer sheet in question #36.
37) The chemical equation listed in the table below describes what happens when you mix aluminum
oxide (2Al2O3) and carbon (3C) together.
2Al2O3 + 3C  4Al + 3CO2
Beginning mass of Reactants
150 g
Mass of 4Al (in Product)
135 g
Mass of 3CO2 (in Product)
?g
How many grams of Carbon dioxide gas (CO2) should have been released, according to the law of
conservation of mass? Write the answer in #37 of your answer sheet.
Balance the following equations – Write the coefficients in the answer grid.
Name:
Period:
Date:
Answer Grid – Record your answers in the space provided below:
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