Chemistry: The Central Science – Theodore L. Brown
Midterm Actual Exam Questions & Answers (100%
verified) |A Grade |2025/2026
Question: What is the physical state in which matter has no specific shape but does have a specific
volume? - Correct ✓✓ A.
gas
B.
solid
C.
liquid
D.
salts
E.
ice
Question: Which one of the following is often easily separated into its components by simple
techniques such as filtering or decanting? - Correct ✓✓ heterogeneous mixture
compound
homogeneous mixture
elements
solutions
Question: If matter is uniform throughout and cannot be separated into other substances by physical
means, it is __________. - Correct ✓✓ a compound only
either an element or a compound
a homogeneous mixture only
a heterogeneous mixture only
an element only
either a heterogeneous mixture or a heterogeneous mixture
either an element, a compound, or a homogeneous mixture
1|Page
, Question: Identify the properties below that are considered "Physical Properties" of a substance.
Leave unchecked the properties that are "Chemical Properties." - Correct ✓✓ flammability
solubility
density
hardness
ease of oxidation
toxicity in rats
reactivity in acid
color
Question: Which of the following is an illustration of the law of constant composition? - Correct ✓✓
Water boils at 100°C at 1 atm pressure.
Water is 11% hydrogen and 89% oxygen by mass.
Water can be separated into other substances by a chemical process
Water and salt have different boiling points.
Water is a compound.
The amounts of hydrogen and oxygen present after a reaction takes place is the same as the
amounts present before the reaction takes place.
Question: Which of the following is an illustration of the law of conservation of mass? - Correct ✓✓
Water boils at 100°C at 1 atm pressure.
Water is 11% hydrogen and 89% oxygen by mass.
Water can be separated into other substances by a chemical process
Water and salt have different boiling points.
Water is a compound.
The amounts of hydrogen and oxygen present after a reaction takes place is the same as the
amounts present before the reaction takes place.
Question: In the following list, only __________ is not an example of a chemical reaction. - Correct
✓✓ dissolution of a penny in nitric acid
the condensation of water vapor
a burning candle
the formation of polyethylene from ethylene
the rusting of iron
2|Page
,Question: Which one of the following is an intensive property? - Correct ✓✓ mass
temperature
volume
density
amount
Question: Accuracy refers to __________. - Correct ✓✓ how close a measured number is to zero
how close a measured number is to the calculated value
how close a measured number is to other measured numbers
how close a measured number is to the true value
how close a measured number is to infinity
Question: The number with the most significant zeros is __________. - Correct ✓✓ 0.00002510
0.02500001
250000001
2.501 x 10-7
2.5100000
Question: Consider the following selected postulates of Dalton's atomic theory:
(i) Each element is composed of extremely small particles called atoms.
(ii) Atoms are indivisible.
(iii) Atoms of a given element are identical.
(iv) Atoms of different elements are different and have different properties.
Which of these postulates do we know today to no longer be true? - Correct ✓✓ i and ii
ii only
ii and iii
3|Page
, iii only
iii and iv
Question: The charge on an electron was determined in the __________. - Correct ✓✓ cathode ray
tube, by J. J. Thompson
Rutherford gold foil experiment
Millikan oil drop experiment
Dalton atomic theory
atomic theory of matter
Question: In the Rutherford nuclear-atom model, __________. - Correct ✓✓ the heavy subatomic
particles, protons and neutrons, reside in the nucleus
the three principal subatomic particles (protons, neutrons, and electrons) all have essentially the
same mass
the light subatomic particles, protons and neutrons, reside in the nucleus
mass is spread essentially uniformly throughout the atom
the three principal subatomic particles (protons, neutrons, and electrons) all have essentially the
same mass and mass is spread essentially uniformly throughout the atom
Question: Cathode rays are deflected away from a negatively charged plate because __________. -
Correct ✓✓ they are not particles
they are positively charged particles
they are neutral particles
they are negatively charged particles
they are emitted by all matter
Question: Of the three types of radioactivity characterized by Rutherford, which is/are not electrically
charged? - Correct ✓✓ α-rays
α-rays, β-rays, and γ-rays
γ-rays
α-rays and β-rays
α-rays and γ-rays
Question: Which atom has the largest number of neutrons? - Correct ✓✓ phosphorous-30
4|Page
Midterm Actual Exam Questions & Answers (100%
verified) |A Grade |2025/2026
Question: What is the physical state in which matter has no specific shape but does have a specific
volume? - Correct ✓✓ A.
gas
B.
solid
C.
liquid
D.
salts
E.
ice
Question: Which one of the following is often easily separated into its components by simple
techniques such as filtering or decanting? - Correct ✓✓ heterogeneous mixture
compound
homogeneous mixture
elements
solutions
Question: If matter is uniform throughout and cannot be separated into other substances by physical
means, it is __________. - Correct ✓✓ a compound only
either an element or a compound
a homogeneous mixture only
a heterogeneous mixture only
an element only
either a heterogeneous mixture or a heterogeneous mixture
either an element, a compound, or a homogeneous mixture
1|Page
, Question: Identify the properties below that are considered "Physical Properties" of a substance.
Leave unchecked the properties that are "Chemical Properties." - Correct ✓✓ flammability
solubility
density
hardness
ease of oxidation
toxicity in rats
reactivity in acid
color
Question: Which of the following is an illustration of the law of constant composition? - Correct ✓✓
Water boils at 100°C at 1 atm pressure.
Water is 11% hydrogen and 89% oxygen by mass.
Water can be separated into other substances by a chemical process
Water and salt have different boiling points.
Water is a compound.
The amounts of hydrogen and oxygen present after a reaction takes place is the same as the
amounts present before the reaction takes place.
Question: Which of the following is an illustration of the law of conservation of mass? - Correct ✓✓
Water boils at 100°C at 1 atm pressure.
Water is 11% hydrogen and 89% oxygen by mass.
Water can be separated into other substances by a chemical process
Water and salt have different boiling points.
Water is a compound.
The amounts of hydrogen and oxygen present after a reaction takes place is the same as the
amounts present before the reaction takes place.
Question: In the following list, only __________ is not an example of a chemical reaction. - Correct
✓✓ dissolution of a penny in nitric acid
the condensation of water vapor
a burning candle
the formation of polyethylene from ethylene
the rusting of iron
2|Page
,Question: Which one of the following is an intensive property? - Correct ✓✓ mass
temperature
volume
density
amount
Question: Accuracy refers to __________. - Correct ✓✓ how close a measured number is to zero
how close a measured number is to the calculated value
how close a measured number is to other measured numbers
how close a measured number is to the true value
how close a measured number is to infinity
Question: The number with the most significant zeros is __________. - Correct ✓✓ 0.00002510
0.02500001
250000001
2.501 x 10-7
2.5100000
Question: Consider the following selected postulates of Dalton's atomic theory:
(i) Each element is composed of extremely small particles called atoms.
(ii) Atoms are indivisible.
(iii) Atoms of a given element are identical.
(iv) Atoms of different elements are different and have different properties.
Which of these postulates do we know today to no longer be true? - Correct ✓✓ i and ii
ii only
ii and iii
3|Page
, iii only
iii and iv
Question: The charge on an electron was determined in the __________. - Correct ✓✓ cathode ray
tube, by J. J. Thompson
Rutherford gold foil experiment
Millikan oil drop experiment
Dalton atomic theory
atomic theory of matter
Question: In the Rutherford nuclear-atom model, __________. - Correct ✓✓ the heavy subatomic
particles, protons and neutrons, reside in the nucleus
the three principal subatomic particles (protons, neutrons, and electrons) all have essentially the
same mass
the light subatomic particles, protons and neutrons, reside in the nucleus
mass is spread essentially uniformly throughout the atom
the three principal subatomic particles (protons, neutrons, and electrons) all have essentially the
same mass and mass is spread essentially uniformly throughout the atom
Question: Cathode rays are deflected away from a negatively charged plate because __________. -
Correct ✓✓ they are not particles
they are positively charged particles
they are neutral particles
they are negatively charged particles
they are emitted by all matter
Question: Of the three types of radioactivity characterized by Rutherford, which is/are not electrically
charged? - Correct ✓✓ α-rays
α-rays, β-rays, and γ-rays
γ-rays
α-rays and β-rays
α-rays and γ-rays
Question: Which atom has the largest number of neutrons? - Correct ✓✓ phosphorous-30
4|Page
