CHEM 103 Module 3 Exam: Chemical Bonding and Molecular
Geometry 2026/2027 UPDATE
1. Which of the following elements is the most electronegative?
A. Oxygen
B. Fluorine
C. Nitrogen
D. Carbon
Answer: B
Rationale: Fluorine is the most electronegative element on the periodic table, with a value
of approximately 4.0.
2. What is the characteristic of an ionic bond?
A. Sharing of electrons between two non-metals
B. A sea of delocalized electrons
C. Sharing of electrons between two metals
D. The transfer of electrons from a metal to a non-metal
Answer: D
Rationale: Ionic bonds are formed by the electrostatic attraction between oppositely
charged ions, typically resulting from the transfer of electrons from a metal to a non-metal.
,3. Which molecular geometry is associated with a central atom having three
bonding pairs and no lone pairs?
A. Trigonal planar
B. Bent
C. Trigonal pyramidal
D. Tetrahedral
Answer: A
Rationale: According to VSEPR theory, three bonding pairs and zero lone pairs result in a
trigonal planar geometry with 120-degree bond angles.
4. What is the electron domain geometry of a water molecule (H2O)?
A. Bent
B. Linear
C. Trigonal planar
D. Tetrahedral
Answer: D
Rationale: Water has two bonding pairs and two lone pairs, giving it four total electron
domains, which corresponds to a tetrahedral electron domain geometry.
5. Which of the following molecules contains a triple bond?
A. N2
B. F2
C. O2
D. H2
Answer: A
Rationale: Nitrogen (N2) shares three pairs of electrons to satisfy the octet rule, forming a
triple covalent bond.
, 6. What is the formal charge on the Nitrogen atom in the ammonium ion
(NH4+)?
A. 0
B. -1
C. +1
D. +2
Answer: C
Rationale: Formal charge = Valence electrons - (Lone pair electrons + 0.5 * Bonding
electrons). For Nitrogen: 5 - (0 + 4) = +1.
7. A molecule with a central atom that has 4 bonding pairs and 2 lone pairs has
which molecular geometry?
A. Octahedral
B. Square planar
C. See-saw
D. Square pyramidal
Answer: B
Rationale: An AB4E2 system results in a square planar molecular geometry to minimize
repulsion between the two lone pairs.
8. Which hybridization state is associated with a linear molecular geometry,
such as in BeCl2?
A. sp
B. sp2
C. sp3
D. sp3d
Answer: A
Rationale: Linear geometry involves two electron domains, which corresponds to sp
hybridization.
Geometry 2026/2027 UPDATE
1. Which of the following elements is the most electronegative?
A. Oxygen
B. Fluorine
C. Nitrogen
D. Carbon
Answer: B
Rationale: Fluorine is the most electronegative element on the periodic table, with a value
of approximately 4.0.
2. What is the characteristic of an ionic bond?
A. Sharing of electrons between two non-metals
B. A sea of delocalized electrons
C. Sharing of electrons between two metals
D. The transfer of electrons from a metal to a non-metal
Answer: D
Rationale: Ionic bonds are formed by the electrostatic attraction between oppositely
charged ions, typically resulting from the transfer of electrons from a metal to a non-metal.
,3. Which molecular geometry is associated with a central atom having three
bonding pairs and no lone pairs?
A. Trigonal planar
B. Bent
C. Trigonal pyramidal
D. Tetrahedral
Answer: A
Rationale: According to VSEPR theory, three bonding pairs and zero lone pairs result in a
trigonal planar geometry with 120-degree bond angles.
4. What is the electron domain geometry of a water molecule (H2O)?
A. Bent
B. Linear
C. Trigonal planar
D. Tetrahedral
Answer: D
Rationale: Water has two bonding pairs and two lone pairs, giving it four total electron
domains, which corresponds to a tetrahedral electron domain geometry.
5. Which of the following molecules contains a triple bond?
A. N2
B. F2
C. O2
D. H2
Answer: A
Rationale: Nitrogen (N2) shares three pairs of electrons to satisfy the octet rule, forming a
triple covalent bond.
, 6. What is the formal charge on the Nitrogen atom in the ammonium ion
(NH4+)?
A. 0
B. -1
C. +1
D. +2
Answer: C
Rationale: Formal charge = Valence electrons - (Lone pair electrons + 0.5 * Bonding
electrons). For Nitrogen: 5 - (0 + 4) = +1.
7. A molecule with a central atom that has 4 bonding pairs and 2 lone pairs has
which molecular geometry?
A. Octahedral
B. Square planar
C. See-saw
D. Square pyramidal
Answer: B
Rationale: An AB4E2 system results in a square planar molecular geometry to minimize
repulsion between the two lone pairs.
8. Which hybridization state is associated with a linear molecular geometry,
such as in BeCl2?
A. sp
B. sp2
C. sp3
D. sp3d
Answer: A
Rationale: Linear geometry involves two electron domains, which corresponds to sp
hybridization.
