1
CHEM 101 Final Exam Ivy Tech Actual Exam
2026/2027 – Complete Exam-Style Questions with
Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
TABLE OF CONTENTS - OFFICIAL SECTIONS:
Section
Section 1: Atomic Structure & Periodic Table
Section 2: Chemical Bonding & Molecular Geometry
Section 3: Chemical Reactions & Stoichiometry
Section 4: Gases, Liquids, Solids & Solutions
Section 5: Acids, Bases & pH
Section 6: Thermodynamics, Kinetics & Equilibrium
[SECTION 1: Atomic Structure & Periodic Table — Questions 1-15]
Q1: Which subatomic particle determines the identity of an element? A. Neutron B. Electron C.
Proton [CORRECT] D. Nucleus
Correct Answer: C Rationale: The atomic number (Z), which is defined by the number of protons
in the nucleus, uniquely determines the chemical element. Changing the number of protons
changes the element itself. Neutrons (A) determine the isotope, and electrons (B) determine the
ion charge.
Q2: An atom of potassium (K) has an atomic number of 19 and a mass number of 39. How many
neutrons does this atom contain? A. 19 B. 20 C. 20 [CORRECT] D. 58
Correct Answer: C Rationale: The number of neutrons is calculated by subtracting the atomic
number from the mass number (
,2
A−Z
). Therefore,
39−19=20
. This specific isotope is Potassium-39.
Q3: Which of the following statements correctly describes isotopes of the same element? A.
They have the same number of protons but different numbers of electrons. B. They have the
same number of neutrons but different numbers of protons. C. They have the same number of
protons but different numbers of neutrons. [CORRECT] D. They have different chemical
properties.
Correct Answer: C Rationale: Isotopes are variants of a particular chemical element that share
the same number of protons (atomic number) but have different numbers of neutrons (mass
number). Because they have the same electron configuration in their neutral state, they exhibit
similar chemical properties.
Q4: What is the maximum number of electrons that can occupy the principal energy level
n=3
? A. 8 B. 18 C. 18 [CORRECT] D. 32
Correct Answer: C Rationale: The maximum number of electrons in a principal energy level
n
is given by the formula
2n2
. For
n=3
,
2(32)=18
. This accommodates the 3s (2), 3p (6), and 3d (10) subshells.
Q5: Which of the following quantum numbers describes the shape of an orbital? A. Principal
quantum number (
n
) B. Azimuthal quantum number (
l
,3
) [CORRECT] C. Magnetic quantum number (
ml
) D. Spin quantum number (
ms
)
Correct Answer: B Rationale: The azimuthal quantum number (
l
) defines the shape of the orbital (s, p, d, f). The principal quantum number (
n
) determines the energy level/size, while
ml
determines the orientation in space, and
ms
describes the electron's spin direction.
Q6: According to the Pauli Exclusion Principle, which of the following is impossible? A. Two
electrons in the same atom having the same set of four quantum numbers. C. Two electrons in the
same atom having the same set of four quantum numbers. [CORRECT] C. Two electrons
occupying different orbitals with opposite spins. D. An electron having a spin of
+1/2
.
Correct Answer: C Rationale: The Pauli Exclusion Principle states that no two electrons in an
atom can have the same set of four quantum numbers. Since three quantum numbers describe the
orbital, the fourth (spin) must be different, meaning only two electrons (with opposite spins) can
occupy a single orbital.
Q7: Which electron configuration represents an atom in an excited state? A.
1s22s22p63s23p54s1
(for Chlorine) [CORRECT] B.
1s22s22p6
(for Neon) C.
, 4
1s22s22p63s2
(for Magnesium) D.
1s22s22p63s23p6
(for Argon)
Correct Answer: A Rationale: Ground state Chlorine is
1s22s22p63s23p5
. The configuration in option A moves an electron from the 3p subshell to the 4s subshell, which
requires an input of energy and represents an excited state. Options B, C, and D represent the
ground states of Neon, Magnesium, and Argon, respectively.
Q8: Which of the following elements has the highest electronegativity? A. Carbon B. Nitrogen
C. Fluorine [CORRECT] D. Oxygen
Correct Answer: C Rationale: Electronegativity is the ability of an atom to attract electrons. It
generally increases across a period (left to right) and decreases down a group. Fluorine is located
in the upper right of the periodic table (excluding noble gases) and has the highest
electronegativity value (approximately 4.0).
Q9: Which of the following atoms has the largest atomic radius? A. Potassium (K) [CORRECT]
B. Calcium (Ca) C. Scandium (Sc) D. Chlorine (Cl)
Correct Answer: A Rationale: Atomic radius increases down a group and decreases across a
period (left to right). All these elements are in Period 4. Since Potassium is the farthest to the left
(Group 1), it has the largest atomic radius because it experiences less effective nuclear charge
pulling the electrons in.
Q10: Which of the following ions is isoelectronic with Argon (Ar)? A.
Cl−
B.
Cl−
[CORRECT] C.
K2+
D.
Ca2+
Correct Answer: B Rationale: Argon has 18 electrons. A chloride ion (
CHEM 101 Final Exam Ivy Tech Actual Exam
2026/2027 – Complete Exam-Style Questions with
Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
TABLE OF CONTENTS - OFFICIAL SECTIONS:
Section
Section 1: Atomic Structure & Periodic Table
Section 2: Chemical Bonding & Molecular Geometry
Section 3: Chemical Reactions & Stoichiometry
Section 4: Gases, Liquids, Solids & Solutions
Section 5: Acids, Bases & pH
Section 6: Thermodynamics, Kinetics & Equilibrium
[SECTION 1: Atomic Structure & Periodic Table — Questions 1-15]
Q1: Which subatomic particle determines the identity of an element? A. Neutron B. Electron C.
Proton [CORRECT] D. Nucleus
Correct Answer: C Rationale: The atomic number (Z), which is defined by the number of protons
in the nucleus, uniquely determines the chemical element. Changing the number of protons
changes the element itself. Neutrons (A) determine the isotope, and electrons (B) determine the
ion charge.
Q2: An atom of potassium (K) has an atomic number of 19 and a mass number of 39. How many
neutrons does this atom contain? A. 19 B. 20 C. 20 [CORRECT] D. 58
Correct Answer: C Rationale: The number of neutrons is calculated by subtracting the atomic
number from the mass number (
,2
A−Z
). Therefore,
39−19=20
. This specific isotope is Potassium-39.
Q3: Which of the following statements correctly describes isotopes of the same element? A.
They have the same number of protons but different numbers of electrons. B. They have the
same number of neutrons but different numbers of protons. C. They have the same number of
protons but different numbers of neutrons. [CORRECT] D. They have different chemical
properties.
Correct Answer: C Rationale: Isotopes are variants of a particular chemical element that share
the same number of protons (atomic number) but have different numbers of neutrons (mass
number). Because they have the same electron configuration in their neutral state, they exhibit
similar chemical properties.
Q4: What is the maximum number of electrons that can occupy the principal energy level
n=3
? A. 8 B. 18 C. 18 [CORRECT] D. 32
Correct Answer: C Rationale: The maximum number of electrons in a principal energy level
n
is given by the formula
2n2
. For
n=3
,
2(32)=18
. This accommodates the 3s (2), 3p (6), and 3d (10) subshells.
Q5: Which of the following quantum numbers describes the shape of an orbital? A. Principal
quantum number (
n
) B. Azimuthal quantum number (
l
,3
) [CORRECT] C. Magnetic quantum number (
ml
) D. Spin quantum number (
ms
)
Correct Answer: B Rationale: The azimuthal quantum number (
l
) defines the shape of the orbital (s, p, d, f). The principal quantum number (
n
) determines the energy level/size, while
ml
determines the orientation in space, and
ms
describes the electron's spin direction.
Q6: According to the Pauli Exclusion Principle, which of the following is impossible? A. Two
electrons in the same atom having the same set of four quantum numbers. C. Two electrons in the
same atom having the same set of four quantum numbers. [CORRECT] C. Two electrons
occupying different orbitals with opposite spins. D. An electron having a spin of
+1/2
.
Correct Answer: C Rationale: The Pauli Exclusion Principle states that no two electrons in an
atom can have the same set of four quantum numbers. Since three quantum numbers describe the
orbital, the fourth (spin) must be different, meaning only two electrons (with opposite spins) can
occupy a single orbital.
Q7: Which electron configuration represents an atom in an excited state? A.
1s22s22p63s23p54s1
(for Chlorine) [CORRECT] B.
1s22s22p6
(for Neon) C.
, 4
1s22s22p63s2
(for Magnesium) D.
1s22s22p63s23p6
(for Argon)
Correct Answer: A Rationale: Ground state Chlorine is
1s22s22p63s23p5
. The configuration in option A moves an electron from the 3p subshell to the 4s subshell, which
requires an input of energy and represents an excited state. Options B, C, and D represent the
ground states of Neon, Magnesium, and Argon, respectively.
Q8: Which of the following elements has the highest electronegativity? A. Carbon B. Nitrogen
C. Fluorine [CORRECT] D. Oxygen
Correct Answer: C Rationale: Electronegativity is the ability of an atom to attract electrons. It
generally increases across a period (left to right) and decreases down a group. Fluorine is located
in the upper right of the periodic table (excluding noble gases) and has the highest
electronegativity value (approximately 4.0).
Q9: Which of the following atoms has the largest atomic radius? A. Potassium (K) [CORRECT]
B. Calcium (Ca) C. Scandium (Sc) D. Chlorine (Cl)
Correct Answer: A Rationale: Atomic radius increases down a group and decreases across a
period (left to right). All these elements are in Period 4. Since Potassium is the farthest to the left
(Group 1), it has the largest atomic radius because it experiences less effective nuclear charge
pulling the electrons in.
Q10: Which of the following ions is isoelectronic with Argon (Ar)? A.
Cl−
B.
Cl−
[CORRECT] C.
K2+
D.
Ca2+
Correct Answer: B Rationale: Argon has 18 electrons. A chloride ion (
