1
CHEM 103 General Chemistry I Portage Learning
Modules 1-6 & Final Exam Actual Exam 2026/2027 –
Complete Exam-Style Questions with Detailed
Rationales | Pass Guaranteed – A+ Graded
[MODULE 1: Matter, Measurement & Atomic Structure — Questions 1-25]
Q1: Which of the following is an example of a chemical property of matter?
A. Density
B. Melting point
C. Flammability
D. Boiling point
Correct Answer: C
Rationale: A chemical property describes a substance's ability to undergo a chemical change or
reaction. Flammability describes how easily a substance burns, which is a chemical reaction with
oxygen. Density, melting point, and boiling point are physical properties because they describe
the state or physical condition of a substance without changing its chemical identity.
Q2: Convert 0.0045 kilograms to milligrams.
A. 4.5 mg
B. 45 mg
C. 450 mg
D. 4500 mg
Correct Answer: D
Rationale: To convert kilograms to milligrams, one must move the decimal point six places to the
right (1 kg = 1,000,000 mg). Therefore, 0.0045 kg becomes 4,500 mg. 4.5 mg is off by a factor
of 1000, and 450 mg is off by a factor of 10.
,2
Q3: How many significant figures are in the measurement 0.00250?
A. 2
B. 3
C. 4
D. 5
Correct Answer: B
Rationale: Leading zeros in decimal numbers are not significant; they only serve to locate the
decimal point. Therefore, 0.00250 has three significant figures: the 2, 5, and the trailing zero.
The trailing zero is significant because it indicates precision.
Q4: Which subatomic particle has a positive charge and is found in the nucleus?
A. Electron
B. Neutron
C. Proton
D. Isotope
Correct Answer: C
Rationale: Protons are positively charged particles located within the nucleus of an atom.
Electrons are negatively charged and orbit the nucleus, while neutrons have no charge. Isotopes
are variants of an element defined by neutron count, not a particle itself.
Q5: Calculate the density of a substance with a mass of 24.6 grams and a volume of 12.0 mL.
A. 0.487 g/mL
B. 2.05 g/mL
C. 12.6 g/mL
D. 295.2 g/mL
,3
Correct Answer: B
Rationale: Density is calculated by dividing mass by volume (). . The answer is limited to three
significant figures because the volume (12.0) has three significant figures.
Q6: Which of the following represents a physical change?
A. Rusting of iron
B. Burning wood
C. Dissolving sugar in water
D. Baking a cake
Correct Answer: C
Rationale: Dissolving sugar in water is a physical change because the sugar molecules remain
chemically the same; they are just dispersed in the solvent. Rusting, burning, and baking involve
chemical reactions where new substances are formed.
Q7: Identify the isotope of Carbon-14 () compared to Carbon-12 ().
A. Carbon-14 has two fewer protons.
B. Carbon-14 has two more electrons.
C. Carbon-14 has two more neutrons.
D. Carbon-14 has a different atomic number.
Correct Answer: C
Rationale: Isotopes are atoms of the same element (same atomic number/proton count) that have
different mass numbers due to different numbers of neutrons. Carbon-14 has 6 protons and 8
neutrons, whereas Carbon-12 has 6 protons and 6 neutrons.
Q8: What is the ground state electron configuration for Nitrogen ()?
A. B. C. D.
Correct Answer: C
, 4
Rationale: Nitrogen has an atomic number of 7, meaning it has 7 electrons. Following the
Aufbau principle, orbitals fill in order: (2 electrons), (2 electrons), leaving 3 electrons for the
subshell. The configuration is .
Q9: Which principle states that no two electrons in an atom can have the same set of four
quantum numbers?
A. Aufbau Principle
B. Heisenberg Uncertainty Principle
C. Pauli Exclusion Principle
D. Hund's Rule
Correct Answer: C
Rationale: The Pauli Exclusion Principle states that an orbital can hold a maximum of two
electrons, and these two electrons must have opposite spins. This ensures that every electron in
an atom has a unique "address" (quantum numbers).
Q10: Express the number 0.000390 in scientific notation.
A. B. C. D.
Correct Answer: B
Rationale: To convert to scientific notation, move the decimal point until there is one non-zero
digit to the left of it. Here, we move it 4 places to the right to get 3.90, so the exponent is -4.
Q11: Which of the following elements is a transition metal?
A. Sodium (Na)
B. Calcium (Ca)
C. Iron (Fe)
D. Argon (Ar)
Correct Answer: C
CHEM 103 General Chemistry I Portage Learning
Modules 1-6 & Final Exam Actual Exam 2026/2027 –
Complete Exam-Style Questions with Detailed
Rationales | Pass Guaranteed – A+ Graded
[MODULE 1: Matter, Measurement & Atomic Structure — Questions 1-25]
Q1: Which of the following is an example of a chemical property of matter?
A. Density
B. Melting point
C. Flammability
D. Boiling point
Correct Answer: C
Rationale: A chemical property describes a substance's ability to undergo a chemical change or
reaction. Flammability describes how easily a substance burns, which is a chemical reaction with
oxygen. Density, melting point, and boiling point are physical properties because they describe
the state or physical condition of a substance without changing its chemical identity.
Q2: Convert 0.0045 kilograms to milligrams.
A. 4.5 mg
B. 45 mg
C. 450 mg
D. 4500 mg
Correct Answer: D
Rationale: To convert kilograms to milligrams, one must move the decimal point six places to the
right (1 kg = 1,000,000 mg). Therefore, 0.0045 kg becomes 4,500 mg. 4.5 mg is off by a factor
of 1000, and 450 mg is off by a factor of 10.
,2
Q3: How many significant figures are in the measurement 0.00250?
A. 2
B. 3
C. 4
D. 5
Correct Answer: B
Rationale: Leading zeros in decimal numbers are not significant; they only serve to locate the
decimal point. Therefore, 0.00250 has three significant figures: the 2, 5, and the trailing zero.
The trailing zero is significant because it indicates precision.
Q4: Which subatomic particle has a positive charge and is found in the nucleus?
A. Electron
B. Neutron
C. Proton
D. Isotope
Correct Answer: C
Rationale: Protons are positively charged particles located within the nucleus of an atom.
Electrons are negatively charged and orbit the nucleus, while neutrons have no charge. Isotopes
are variants of an element defined by neutron count, not a particle itself.
Q5: Calculate the density of a substance with a mass of 24.6 grams and a volume of 12.0 mL.
A. 0.487 g/mL
B. 2.05 g/mL
C. 12.6 g/mL
D. 295.2 g/mL
,3
Correct Answer: B
Rationale: Density is calculated by dividing mass by volume (). . The answer is limited to three
significant figures because the volume (12.0) has three significant figures.
Q6: Which of the following represents a physical change?
A. Rusting of iron
B. Burning wood
C. Dissolving sugar in water
D. Baking a cake
Correct Answer: C
Rationale: Dissolving sugar in water is a physical change because the sugar molecules remain
chemically the same; they are just dispersed in the solvent. Rusting, burning, and baking involve
chemical reactions where new substances are formed.
Q7: Identify the isotope of Carbon-14 () compared to Carbon-12 ().
A. Carbon-14 has two fewer protons.
B. Carbon-14 has two more electrons.
C. Carbon-14 has two more neutrons.
D. Carbon-14 has a different atomic number.
Correct Answer: C
Rationale: Isotopes are atoms of the same element (same atomic number/proton count) that have
different mass numbers due to different numbers of neutrons. Carbon-14 has 6 protons and 8
neutrons, whereas Carbon-12 has 6 protons and 6 neutrons.
Q8: What is the ground state electron configuration for Nitrogen ()?
A. B. C. D.
Correct Answer: C
, 4
Rationale: Nitrogen has an atomic number of 7, meaning it has 7 electrons. Following the
Aufbau principle, orbitals fill in order: (2 electrons), (2 electrons), leaving 3 electrons for the
subshell. The configuration is .
Q9: Which principle states that no two electrons in an atom can have the same set of four
quantum numbers?
A. Aufbau Principle
B. Heisenberg Uncertainty Principle
C. Pauli Exclusion Principle
D. Hund's Rule
Correct Answer: C
Rationale: The Pauli Exclusion Principle states that an orbital can hold a maximum of two
electrons, and these two electrons must have opposite spins. This ensures that every electron in
an atom has a unique "address" (quantum numbers).
Q10: Express the number 0.000390 in scientific notation.
A. B. C. D.
Correct Answer: B
Rationale: To convert to scientific notation, move the decimal point until there is one non-zero
digit to the left of it. Here, we move it 4 places to the right to get 3.90, so the exponent is -4.
Q11: Which of the following elements is a transition metal?
A. Sodium (Na)
B. Calcium (Ca)
C. Iron (Fe)
D. Argon (Ar)
Correct Answer: C
