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1.2 District Pre-AP Exam (TEKS 6.5ABC)
2014 - 2015
1. How would you classify the following substances: (6.5A)
1234A.
B.
C.
D.
H2O2
O2
HCl
C6H12O6
1, 2 & 3 are elements, while 4 is a compound
1 and 3 are elements, while 2 and 4 are compounds
2 is an element, while 1, 2 & 4 are compounds
1 is an element, while 2, 3 & 4 are compounds
2. Which of the following is the best explanation(s) of an element? (6.5A)
I. A
II. A
III. A
IV. A
substance that cannot be broken down into simpler substances
naturally occurring mineral made of more than one substance
small particle made with a specific chemical composition
collection of atoms that have different abilities when joined together.
A.
B.
C.
D.
I only
I and II only
II only
III and IV only
3. Provided below are five different substances:
How many of these substances are elements? (6.5A)
Record your answer in the grid.
4. A group of students are distinguishing between elements, compounds, and
mixtures. Which substance below would be categorized with’ Pure
Substances’. (6.5A, 6.3B)
5. Two elements make up about 75% of the mass for all elements found in
Earth’s crust. The two most abundant (common) elements found in Earth’s
crust are? (6.5B)
A.
B.
C.
D.
Silicon and Aluminum
Chlorine and Sodium
Iron and Oxygen
Oxygen and Silicon
6. Which graph below best shows the composition of Earth’s atmosphere? (6.5B)
A
C
B
D
7. Which statement is the best comparison of elements and compounds? (6.5C)
A. Elements are pure substances that contain only one type of atom,
and compounds are mixtures of elements.
B. Elements are two or more atoms chemically bonded together, and
compounds are pure substances that contain only one type of atom.
C. Elements are pure substances that contain only one type of atom,
and compounds are two or more different atoms chemically bonded
together.
D. Elements are mixtures of pure substances, and compounds are
mixtures of different substances.
8. The formula for Sodium Chloride (salt) is NaCl. Based on your knowledge,
how would you best classify Sodium Chloride? (6.5C)
A.
B.
C.
D.
A
A
A
A
compound because there are two elements
pure substance because it is a seasoning for food
mixture because it has two things in it
solution because everything is a solution
9. Use the information in the table below to answer the following question.
Element
Hg
I
Li
Compound
H2O
NaCl
C6H12O6
Based on the pattern in the table, is O2 a compound? (6.5C)
A.
B.
C.
D.
Yes, because it contains two atoms.
No, because it is not a pure substance.
Yes, because it is not a pure substance.
No, because it does not contain at least two different atoms.
10. A science student is assigned to write a paper on a common compound.
Which substance could the student choose for this assignment? (6.5C)
A.
B.
C.
D.
Hydrogen
Gold
Water
Helium
11. A science student was given LEGO blocks and asked to build a compound.
How could the student ensure the model could be identified as a compound?
(6.3 BC, 6.5C)
A. Use different sizes of the same color LEGO blocks to represent the
parts of the compound.
B. Build the model so that it is shaped like a compound.
C. Stack five LEGO blocks in a tower
D. Have a specific color of LEGO blocks represent each element in the
compound.
12. Sulfur reacts with other elements to form new substances, but sulfur cannot
be broken into simpler substances. Based on this information, how is sulfur
categorized? (6.5A)
A.
B.
C.
D.
Solution
Element
Compound
Mixture
13. Part of the periodic Table is shown below. Read the answer choices carefully.
Which statement most accurately classifies these
substances? (6.5C)
A. Hydrogen and potassium are elements because
their symbols only contain one letter.
B. Lithium, beryllium, sodium, magnesium, and
calcium are elements because their symbols contain
two or more letters.
C. Hydrogen, lithium, beryllium, sodium, magnesium,
potassium, and calcium are all elements, because only
elements are listed on the Periodic Table.
D. Hydrogen, lithium, beryllium, sodium, magnesium,
potassium, and calcium are not elements because
only compounds are listed on the Periodic Table.
14. Of the substances pictured below, which model represents a compound?
(6.3B, 6.5C)
A.
B.
C.
D.
15. In the science lab, students are instructed to create models of carbon
dioxide (CO2) molecules using commonly available materials. One group
makes a molecule model using toothpicks to join two balls of blue modeling
clay to one ball of red modeling clay. What is a limitation of this model?
(6.3C, 6.5C)
A. Toothpicks are made of wood and float.
B. Clay cannot demonstrate any of the properties of a carbon dioxide
molecule because the molecules are too small to see.
C. Clay cannot represent gas molecules.
D. The balls of clay can be pulled apart, while a carbon dioxide molecule
cannot be separated into simpler substances.
16. You are teaching a friend about the differences between elements and
compounds. You show your friend this chemical reaction:
Fe + S  FeS
Which substance in the chemical reaction is a compound and how would you
explain it to your friend? (6.5C)
A. Fe is the compound because it has two letters and each letter
represents a different element.
B. FeS is the compound because it has two capital letters and each
capital letter represents a different element.
C. FeS is the compound because it is at the end of the reaction and
compounds are always created when you add two substances
together.
D. Fe is the compound because it is at the beginning of the reaction and
compounds are always at the beginning.
17. When magnesium (Mg) metal is burned in the presence of Oxygen (O2),
magnesium oxide (MgO) is produced. The properties of magnesium oxide are
different than the individual properties of magnesium and oxygen because
magnesium oxide is ___________________. (6.5C)
A.
B.
C.
D.
A solution
A mixture
A compound
An element
18. Describe the product of the following chemical reaction. (6.5C)
CaCO3
A.
B.
C.
D.
One
One
Two
Two

CaO + CO2
element
compound
elements
compounds
19. Carbon dioxide (CO2) is not found on the Periodic Table because carbon
dioxide is ________________. (6.5C)
A.
B.
C.
D.
An atom
A compound
A gas
A mixture
20. A scientist was writing observations of samples in his lab. Which of the
following samples was most likely a living organism based on the elements
that compose it and the characteristics? (6.5B)
Sample
W
X
Y
Z
A.
B.
C.
D.
Elements found in the sample
silicon, aluminum, iron
oxygen
carbon, oxygen, hydrogen
sodium, chlorine
Characteristics
gray and red solid
clear gas
green and brown solid
white and clear solid
W
x
Y
Z
21. Look at the equation below.
CH4 + 2O2

CO2 + 2 H2O
How many different elements are in the reaction? (6.5C)
Record your answer in the grid on your answer document.
22. The majority of the Earth’s oceans are composed of water (H2O). If the
elements Hydrogen and Oxygen make up most of the Earth’s oceans, then
what are the two elements that make up the salinity of the ocean? (6.5B)
A.
B.
C.
D.
Nitrogen and sulfur
Sodium and chloride
Silicon and aluminum
Fluorine and carbon
23. The chemical equation for hydrochloric acid is H + Cl  HCl. Which correctly
identifies each side of the chemical equation? (6.5C)
A.
B.
C.
D.
elements  compound
compounds  compound
elements  element
compounds  mixture
24. Look at the given compound.
Be3Al2(SiO3)6
How many different elements are in the compound? (6.5C)
Record your answer in the grid on your answer document.
25. Which of the following are pure substances? (6.5A)
I.
II.
III.
IV.
A.
B.
C.
D.
Concrete
Wood
Milk
Elemental Copper
I only
II and IV only
III and IV only
IV only