Grade 8 Physical Pretest
Select the best answer to each question.
____
1. Tyson draws a model to show how the particles in a liquid appear.
Which model (or models) above could be Tyson’s drawing of particles in a liquid?
A.
B.
C.
D.
model 1
model 3
model 1 and model 2
model 1, model 2, and model 3
____
2. Nicholas is using a computer model to study the motion of solids, liquids, and gases. The adjusts the settings
so the model shows particles that are far apart and move randomly in all directions. Which state(s) of matter is
Nicholas viewing with current model?
A. gas
B. liquid
C. solid
D. gas, liquid, and solid
____
3. Liam is building a model of the particles in liquid iron and solid iron. He uses plastic foam balls to represent
the particles. How should he connect the balls in the model of solid iron to show the motion of the particles?
A. They should be connected with springs.
B. They should be connected with wooden sticks.
C. They should be glued together in an orderly way.
D. They should be placed in a clear box, but not connected.
____
4. A metal coin has certain properties that can be measured. Which property of a coin is different on the moon
than it is on Earth?
A.
B.
C.
D.
____
density
mass
volume
weight
5. Abed measures the weight of four unknown samples that have the same volume.
Sample
1
2
3
4
WEIGHT OF SAMPLES
Weight (N)
0.25
0.14
0.29
0.25
Which statement describes the masses of the samples?
A. Sample 2 has the greatest mass.
B. Samples 1 and 4 have the same mass.
C. All of the samples have the same mass.
D. The mass needs to be measured to compare the relative masses.
____
6. Donna measured the mass of an aluminum block to be 53.8 g. Which of the following did she measure?
A.
B.
C.
D.
____
the density of the block
the amount of matter in the block
the gravitational pull on the block
the amount of atmospheric pressure on the block
7. In a science lab, Paula used a ruler to measure the block of material shown below. She also measured the
mass of the block as 400 grams.
What is the density of this block?
A.
B.
C.
D.
____
0.75 g/cm3
1.25 g/cm3
1.33 g/cm3
300 g/cm3
8. Elizabeth wants to know the volume of a glass figurine that is irregularly shaped. She learns that the density
of the glass used to make the figurine is 3.1 grams/cubic centimeter (g/cm3). She measures the mass to be 403
g. The equation for density is d = m/V. What is the volume of the glass figurine?
A. 0 cm3
B. 0.0077 cm3
C. 130 cm3
D. 1,250 cm3
____
9. Sofia is comparing the properties of four objects. Each object has a different shape: a square, a thin box, a
sphere, and an irregular shape. The masses of all of the objects are the same. Which object must have the
greatest density?
A.
B.
C.
D.
the object shaped like a sphere
the object with the irregular shape
the object with the largest volume
the object with the smallest volume
____ 10. Kim is a forensic scientist. She has been asked to identify a chemical compound that was found at the scene of
a crime. Which of these pairs of properties would be most helpful in identifying the unknown compound?
A. color, mass
B. boiling point, volume
C. flammability, volume
D. melting point, reactivity with water
____ 11. Andrea adds a clear liquid, a green liquid, and a black liquid to a beaker. She observes the liquids after 5
minutes. The clear liquid is on top of the green liquid, and the green liquid is on top of the black liquid.
What is the order of density of the liquids, from highest to lowest?
A. black > green > clear
B. black > clear > green
C. clear > green > black
D. green > black > clear
____ 12. Camila is testing the thermal conductivity of different materials. She places four spoons in a bowl as shown in
the picture below and touches the handle of each spoon after 60 seconds.
Which spoons does she classify as thermally conductive?
A. the plastic spoon and the silver spoon
B. the wooden spoon and the plastic spoon
C. the stainless steel spoon and the wood spoon
D. the silver spoon and the stainless steel spoon
____ 13. Reactant A and reactant B undergo a chemical reaction to form product C.
What type of substance is reactant B?
A. a nucleus
B. a mixture
C. an element
D. a compound
____ 14. Jorgen takes a drink of water to cool down after playing basketball. What do Jorgen, the basketball, and the
water all have in common?
A. They are made of atoms of elements.
B. They are made of the same compounds.
C. They are each made of one type of element.
D. They are each made of one type of compound.
____ 15. Maya is classifying substances as compounds or elements. Which of the following substances is a compound?
A. carbon
B. fluorine
C. oxygen
D. water
____ 16. The periodic table of the elements is divided by a zigzag line. The elements on either side of the line have
distinct properties.
Which of the following is true for most of the elements that lie along the zigzag line?
A.
B.
C.
D.
They are metalloids.
They are nonmetals.
They are transition metals.
They are metals.
____ 17. Elements are classified as metals, nonmetals, and metalloids because each of those types of elements has
common properties. Where are the most nonmetals found in the periodic table?
A. in the bottom 2 rows
B. in the 2 far left columns
C. in the 5 far right columns
D. in the middle 10 columns
____ 18. The periodic table is used to organize the elements based on the similarity of their properties. Sulfur (S) is in
a column next to fluorine (F). Which difference explains why sulfur and fluorine are grouped in different
columns?
A. sizes
B. properties
C. atomic masses
D. atomic numbers
____ 19. Which model of an atom is correctly labeled?
A.
B.
C.
D.
____ 20. The atomic theory has changed as scientists discovered more information about atoms. Which of the
following statements follows the current understanding of atoms?
A. All atoms are the same.
B. Atoms are the smallest unit of an element.
C. Atoms cannot be divided into smaller parts.
D. There is an infinite number of kinds of atoms.
____ 21. Atoms of elements are electrically neutral unless they gain or lose electrons. Why are atoms and not electrons
considered to be the smallest unit of an element?
A. Electrons are larger than atoms.
B. Atoms of most elements do not contain electrons.
C. Atoms cannot be divided into smaller particles like electrons.
D. Atoms are the smallest unit that has the properties of an element
____ 22. Which of these substances is a compound?
A. chlorine
B. nitrogen
C. uranium
D. ammonia
____ 23. Davis adds two different salts to two different glasses of water and stirs each glass of water. He shines a
flashlight at each glass and observes that the water in Glass A appears clear, while the water in Glass B
appears cloudy.
Which conclusion do the results support?
A. The salt in Glass A is soluble in water.
B. The salt in Glass B is soluble in water.
C. The salt in Glass A is denser than water.
D. The salt in Glass B is denser than water.
____ 24. Zoe reads that bleach is a strong base. Which of the following could be the pH of bleach?
A.
B.
C.
D.
2
7
8
12
____ 25. Solution is another name for what type of matter?
A. element
B. compound
C. homogeneous mixture
D. heterogeneous mixture
____ 26. Chad adds several drops of oil to a sample of water.
Which of the following does Chad make?
A. mixture
B. solution
C. compound
D. pure substance
____ 27. Soda water is made by adding gaseous carbon dioxide to pure water to make a uniform mixture of water and
carbon dioxide gas. Which statement best classifies soda water?
A.
B.
C.
D.
It is not a solution because it contains a gas and a liquid.
It is a solution because it is a uniform mixture of two substances.
It is not a solution because the carbon dioxide gas does not dissolve.
It is a solution because the water and carbon dioxide gas combine chemically.
____ 28. Which types of changes observe the law of conservation of mass?
A.
B.
C.
D.
only changes of state
only physical changes
only chemical changes
physical changes and chemical changes
____ 29. The illustration below shows two beakers. In science class, Mr. Mendez dissolves salt from one beaker into
the beaker of water. The salt disappears into the water.
What will be the resulting mass of the salt water?
A. 100 g
B. 101 g
C. 110 g
D. 120 g
____ 30. Jabril blows up a balloon. The mass of the balloon and the air is 6 g. The diameter of the balloon is 12 cm. He
heats the balloon gently. As the temperature of the air increases, the balloon expands to 15 cm. How has the
mass of the air been affected by the addition of heat to the balloon?
A.
B.
C.
D.
The mass is less.
The mass is greater.
The mass is the same.
There is no way to measure the change in mass.
____ 31. Matter can undergo physical and chemical changes. A physical change is a change of matter from one form to
another without a change in the identify of the substance. Which process is an example of a physical change?
A. ice melting
B. milk souring
C. metal rusting
D. wood burning
____ 32. Mr. Hodges and his brother go camping. Mr. Hodges cuts wood for the fire. His brother cooks a hotdog while
coffee brews over the campfire. Steam escapes from the coffee pot.
What type or types of changes are present in this illustration?
A. physical changes only
B. chemical changes only
C. both physical and chemical changes
D. neither physical nor chemical changes
____ 33. The Alvarez family is having a picnic. Several changes in matter take place during the picnic. Which of these
events represents a chemical change?
A.
B.
C.
D.
Luis cuts a piece of watermelon.
Maria folds the napkins to look like swans.
Mrs. Alvarez crumbles a piece of aluminum foil.
Mr. Alvarez cooks cheeseburgers on the charcoal grill.
____ 34. Mr. Molina makes jewelry. He is going to make a ring using an alloy of yellow gold and silver. The melting
point of gold is 1064 °C. The melting point of silver is 962 °C. To blend the two metals together, he must
melt them in a jeweler’s furnace. What is the lowest temperature Mr. Molina’s furnace must reach to melt the
two metals?
A.
B.
C.
D.
100 °C
962 °C
1064 °C
2026 °C
____ 35. Tran needs to take an antacid tablet. He plans to dissolve the tablet in water.
What could Tran do to increase the rate at which the antacid tablet dissolves?
A. heat the water
B. chill the water
C. increase the amount of water
D. decrease the amount of water
____ 36. Rico is doing an experiment. He makes a solution of calcium carbonate in a beaker of 200 mL of water at
room temperature (25 °C). He adds a small amount of lemon juice to the solution and a chemical reaction
begins. Rico reduces the temperature of the solution by 10 °C by adding ice. As the solution cools, what will
happen to the chemical reaction?
A.
B.
C.
D.
The chemical reaction will stop suddenly.
There will be no change in the rate of the chemical reaction.
The chemical reaction will slow as the water cools.
The speed of the chemical reaction will increase as the water cools.
Grade 8 Physical Pretest
Answer Section
MULTIPLE CHOICE
1. ANS: A
A is correct because the particles are close together, but they are not locked in a rigid arrangement.
B is incorrect because the particles are far apart, so there is little attraction between them.
C is incorrect because only model 1 is a liquid.
D is incorrect because only model 1 is a liquid.
STA: SC.8.P.8.1
2. ANS: A
A is correct because gas particles are far apart and move randomly in all directions.
B is incorrect because the particles are close together and slide past each other.
C is incorrect because the particles in a solid are close together and can only vibrate in place.
D is incorrect because only the particles in a gas are far apart and move randomly in all directions.
STA: SC.8.P.8.1
3. ANS: A
A is correct because the particles should be able to vibrate.
B is incorrect because wooden sticks would not allow the balls to vibrate.
C is incorrect because the balls would not be able to move at all.
D is incorrect because the balls would be able to move past each other, which would represent a liquid.
STA: SC.8.P.8.1
4. ANS: D
A is incorrect because the mass and volume of the coin are the same on the moon, so the density of the coin is
also the same.
B is incorrect because mass is a measure of the amount of matter in an object, which does not change if the
object is on the moon.
C is incorrect because the volume of the coin is the same whether it is on the moon or on Earth.
D is correct because the coin weighs less on the moon, where the gravitational force is weaker.
STA: SC.8.P.8.2
5. ANS: B
A is incorrect because mass and weight are proportional and 2 has the smallest weight.
B is correct because 1 and 4 have the same weight and are the same volume.
C is incorrect because mass is proportional to weight, not volume.
D is incorrect because the relative masses can be determined by knowing the weight.
STA: SC.8.P.8.2
6. ANS: B
A is incorrect because mass and volume are needed to determine density.
B is correct because mass measures the amount of matter in an object.
C is incorrect because mass does not take gravity into account.
D is incorrect because mass is not affected by atmospheric pressure.
STA: SC.8.P.8.2
7. ANS: C
A is incorrect because the mass must be divided by the volume, and not the volume by the mass.
B is incorrect because 400 grams/300 cm3 does not equal 1.25 g/cm3.
C is correct because 400 grams/300 cm3 = 1.33 g/cm3.
D is incorrect because the volume of the object is 300 cm3.
STA: SC.8.P.8.3
8. ANS: C
A is incorrect because even glass objects take up space.
B is incorrect because volume is not equal to density divided by mass.
C is correct because the volume is equal to the mass divided by the density, or 430 g/3.1 g/cm3.
D is incorrect because the volume does not equal density times mass.
STA: SC.8.P.8.3
9. ANS: D
A is incorrect because the density of the sphere depends on its size.
B is incorrect because the irregularly shaped may take up more space than the other objects.
C is incorrect because the object with the largest volume will have the smallest density.
D is correct because density is equal to mass divided by volume, so the object with the smallest volume will
have the greatest density.
STA: SC.8.P.8.3
10. ANS: D
A is incorrect because mass is not a characteristic property. Mass depends on how much matter is in a given
sample. Mass alone would not be useful in identifying the unknown compound.
B is incorrect because volume is not a characteristic property. Volume depends on how much space is taken
up by a given sample. Volume alone would not be useful in identifying the unknown compound.
C is incorrect because volume is not a characteristic property. Volume depends on how much space is taken
up by a given sample. Volume alone would not be useful in identifying the unknown compound.
D is correct because melting point and reactivity are both characteristic properties. They are the same for a
given compound regardless of the amount of the sample present.
STA: SC.8.P.8.4
11. ANS: A
A is correct because the black liquid is on the bottom and the clear liquid is on top of the green liquid.
B is incorrect because the clear liquid is on the top of the green liquid.
C is incorrect because the black liquid is the densest.
D is incorrect because the density of the green liquid is between the densities of the black and clear liquid.
STA: SC.8.P.8.4
12. ANS: D
A is incorrect because plastic is a thermal insulator.
B is incorrect because neither plastic nor wood is thermally conductive.
C is incorrect because wood is a thermal insulator.
D is correct because both silver and stainless steel are good thermal conductors.
STA: SC.8.P.8.4
13. ANS: C
A is incorrect because a nucleus is part of an atom. Reactant B contains whole atoms.
B is incorrect because a mixture contains different types of elements and/or compounds that are physically
combined. Reactant B contains a single type of atom.
C is correct because all atoms of reactant B are the same type, even though more than one atom is in each
unit.
D is incorrect because a compound contains different types of atoms that are chemically combined. Reactant
B contains a single type of atom.
STA: SC.8.P.8.5
14. ANS: A
A is correct because all living and nonliving things are made of elements.
B is incorrect because different things are made up of different compounds.
C is incorrect because the substances that make them up can be broken down further by physical or chemical
means.
D is incorrect because Jorgen and the basketball are made up of more than one type of compound.
STA: SC.8.P.8.5
15. ANS: D
A is incorrect because carbon is an element.
B is incorrect because fluorine cannot be broken down into a simpler substance by chemical means.
C is incorrect because even though oxygen is found as molecule containing two atoms of oxygen, it is an
element.
D is correct because water is made up of two elements combined in a specific ratio.
STA: SC.8.P.8.5
16. ANS: A
A is correct because most of the elements that border the zigzag line are neither metals nor nonmetals, but
have properties of both.
B is incorrect because nonmetals lie to the right of the zigzag line.
C is incorrect because transition metals are in Groups 3 through 12 of the periodic table.
D is incorrect because metals lie to the left of the zigzag line.
STA: SC.8.P.8.6
17. ANS: C
A is incorrect because the bottom two rows are mostly metals.
B is incorrect because metals are found in the first two columns.
C is correct because the nonmetals are all found on the right part of the periodic table.
D is incorrect because the transition metals are found in the middle of the periodic table.
STA: SC.8.P.8.6
18. ANS: B
A is incorrect because atoms of elements in the same column are different sizes going down the column.
B is correct because elements are organized into columns because they have similar properties.
C is incorrect because the atomic mass increases down a column.
D is incorrect because all elements have a unique atomic number.
STA: SC.8.P.8.6
19. ANS: C
A is incorrect because all the particles are labeled incorrectly.
B is incorrect because the neutron and nucleus are labeled incorrectly.
C is correct because all the particles are labeled correctly.
D is incorrect because the proton and neutron are labeled incorrectly.
STA: SC.8.P.8.7
20. ANS: B
A is incorrect because different atoms have different numbers of protons, neutrons, and electrons.
B is correct because atoms are the smallest unit of matter that has the chemical properties of an element.
C is incorrect because atoms are made up of subatomic particles.
D is incorrect because the number of kinds of atoms depends on the limited number of elements and their
isotopes.
STA: SC.8.P.8.7
21. ANS: D
A is incorrect because electrons are much smaller than atoms.
B is incorrect because all neutral atoms contain electrons.
C is incorrect because atoms are made up of electrons, neutrons, and protons.
D is correct because although atoms are composed of smaller particles, they are the smallest unit that has the
property of an element.
STA: SC.8.P.8.7
22. ANS: D
A is incorrect because chlorine is an element.
B is incorrect because nitrogen is an element.
C is incorrect because uranium is an element.
D is correct because ammonia is a compound containing nitrogen and hydrogen.
STA: SC.8.P.8.8
23. ANS: A
A is correct because the clear solution in Glass A indicates that the salt is soluble in water.
B is incorrect because the cloudy solution in Glass B indicates that the salt is insoluble.
C is incorrect because the clarity of the solution indicates solubility, not density.
D is incorrect because the clarity of the solution indicates solubility, not density.
STA: SC.8.P.8.8
24. ANS: D
A is incorrect because a substance with a pH of 2 is a strong acid.
B is incorrect because a substance with a pH of 7 is neutral.
C is incorrect because a substance with a pH of 8 is a weak base.
D is correct because a substance with a pH of 10 is a strong base.
STA: SC.8.P.8.8
25. ANS: C
A is incorrect because a solution contains at least two different types of atoms.
B is incorrect because the parts of a solution are not chemically combined.
C is correct because the parts of a solution are mixed evenly, so the solution is the same throughout.
D is incorrect because a heterogeneous mixture is not the same throughout.
STA: SC.8.P.8.9
26. ANS: A
A is correct because the oil and water combine to form a heterogeneous mixture.
B is incorrect because the mixture is not homogenous, so is not a solution.
C is incorrect because the oil and water are not chemically bonded, so the oil and water have not formed a
compound.
D is incorrect because the combined oil and water do not have a uniform composition, so the result is not a
pure substance.
STA: SC.8.P.8.9
27. ANS: B
A is incorrect because a solution can be made of a gas and a liquid.
B is correct because a solution is a uniform mixture of two substances.
C is incorrect because a substance does not have to dissolve to form a solution.
D is incorrect because the water and carbon dioxide gas do not combine chemically.
STA: SC.8.P.8.9
28. ANS: D
A is incorrect because mass is conserved in all physical and chemical changes.
B is incorrect because mass is also conserved in chemical changes.
C is incorrect because mass is also conserved in physical changes.
D is correct because mass is conserved in all physical and chemical changes.
STA: SC.8.P.9.1
29. ANS: C
A is not correct because the addition of two masses equals the sum of both.
B is not correct because 100 g + 10 g = 110 g.
C is correct because mass is not lost or gained due to a physical change.
D is not correct because adding two masses together will not result in a mass greater than the sum of the two
original masses.
STA: SC.8.P.9.1
30. ANS: C
A is incorrect because the Law of Conservation of Mass states that mass cannot be created or destroyed.
B is incorrect because the Law of Conservation of Mass states that mass cannot be created or destroyed.
C is correct because heat does not change the mass of an object.
D is incorrect because the mass is already given.
STA: SC.8.P.9.1
31. ANS: A
A is correct because ice melting is a state change (from solid to liquid), which is a physical change.
B is incorrect because milk souring is a chemical change, not a physical change.
C is incorrect because metal rusting is a chemical change, not a physical change.
D is incorrect because wood burning is a chemical change, not a physical change.
STA: SC.8.P.9.2
32. ANS: C
A is incorrect because the fire, the coffee brewing, and the cooking hotdog are all examples of chemical
changes.
B is incorrect because cutting wood is a physical change.
C is correct because the fire burning, coffee brewing, and hotdog cooking are chemical changes. The wood
being cut is a physical change.
D is incorrect because cutting wood is a physical change and burning wood is a chemical change.
STA: SC.8.P.9.2
33. ANS: D
A is incorrect because cutting or breaking an object is a physical change.
B is incorrect because folding changes shape, which is a physical change.
C is incorrect because a change of shape is a physical change.
D is correct because cooking represents a chemical change.
STA: SC.8.P.9.2
34. ANS: C
A is incorrect because 100 °C is the boiling point of water. Neither silver nor gold will melt at this
temperature.
B is incorrect because 962 °C will melt the silver but not the gold.
C is correct because the furnace must, at a minimum, reach the highest melting point of any metal used.
D is incorrect because the furnace need only reach the melting point of gold to melt both metals.
STA: SC.8.P.9.3
35. ANS: A
A is correct because heat will increase the speed of dissolution.
B is incorrect because chilling will slow the chemical reaction.
C is incorrect because the amount of water will not change the rate of dissolving.
D is incorrect because the amount of water will not change the rate of dissolving.
STA: SC.8.P.9.3
36. ANS: C
A is incorrect because the solution is not cold enough to completely stop the reaction.
B is incorrect because cooling does change the rate of the chemical reaction.
C is correct because the reaction will slow as the ice melts and the water cools.
D is incorrect because the rate of the reaction slows down as the solution cools.
STA: SC.8.P.9.3