CHEM 219: Module 2 Exam Mastery
Electronic Structure and Bonding
Portage Learning 2026/2027 | 250 Verified Questions
LEWIS STRUCTURES & VALENCE ELECTRONS
Q1: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q2: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q3: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q4: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q5: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
CHEM 219 Module 2 - Page 1
,FORMAL CHARGE
Q6: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
LEWIS STRUCTURES & VALENCE ELECTRONS
Q7: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q8: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q9: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q10: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q11: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
FORMAL CHARGE
Q12: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
CHEM 219 Module 2 - Page 2
,LEWIS STRUCTURES & VALENCE ELECTRONS
Q13: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q14: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q15: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q16: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q17: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
FORMAL CHARGE
Q18: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
LEWIS STRUCTURES & VALENCE ELECTRONS
Q19: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
CHEM 219 Module 2 - Page 3
, BONDING - POLAR VS NONPOLAR
Q20: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q21: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q22: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q23: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
FORMAL CHARGE
Q24: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
LEWIS STRUCTURES & VALENCE ELECTRONS
Q25: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q26: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
CHEM 219 Module 2 - Page 4
Electronic Structure and Bonding
Portage Learning 2026/2027 | 250 Verified Questions
LEWIS STRUCTURES & VALENCE ELECTRONS
Q1: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q2: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q3: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q4: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q5: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
CHEM 219 Module 2 - Page 1
,FORMAL CHARGE
Q6: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
LEWIS STRUCTURES & VALENCE ELECTRONS
Q7: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q8: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q9: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q10: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q11: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
FORMAL CHARGE
Q12: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
CHEM 219 Module 2 - Page 2
,LEWIS STRUCTURES & VALENCE ELECTRONS
Q13: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q14: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q15: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q16: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q17: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
FORMAL CHARGE
Q18: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
LEWIS STRUCTURES & VALENCE ELECTRONS
Q19: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
CHEM 219 Module 2 - Page 3
, BONDING - POLAR VS NONPOLAR
Q20: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
VSEPR & MOLECULAR GEOMETRY
Q21: What is the molecular geometry of Ammonia (NH3)?
A. Tetrahedral | B. Trigonal Planar | C. Trigonal Pyramidal | D. Bent
Correct Answer: C
Concept: Nitrogen has 3 bonding pairs and 1 lone pair. While the electron geometry is tetrahedral, the presence of the lone pair
makes the molecular shape trigonal pyramidal.
HYBRIDIZATION
Q22: What is the hybridization of the carbon atom in Ethene (C2H4)?
A. sp | B. sp2 | C. sp3 | D. dsp3
Correct Answer: B
Concept: In ethene, each carbon is bonded to three other atoms (two H and one C via a double bond). Three electron domains
correspond to sp2 hybridization and a trigonal planar geometry.
RESONANCE
Q23: Which statement about resonance structures is true?
A. The molecule flips back and forth between structures. | B. Only electrons move, nuclei remain stationary. | C. One
structure is more 'real' than the others. | D. Resonance occurs only in ionic compounds.
Correct Answer: B
Concept: Resonance structures are a way of describing delocalized electrons. The actual molecule is a hybrid. Only pi electrons
and lone pairs move; the sigma framework (atomic nuclei) remains the same.
FORMAL CHARGE
Q24: Calculate the formal charge of the Oxygen atom in the Hydronium ion (H3O+).
A. -1 | B. 0 | C. +1 | D. +2
Correct Answer: C
Concept: Formal Charge = [Valence Electrons] - [Unshared Electrons + 1/2 Shared Electrons]. For O in H3O+: 6 - [2 + (1/2 * 6)] = 6 -
5 = +1.
LEWIS STRUCTURES & VALENCE ELECTRONS
Q25: How many valence electrons are present in a molecule of Methane (CH4)?
A. 4 | B. 6 | C. 8 | D. 10
Correct Answer: C
Concept: Carbon has 4 valence electrons and each of the 4 Hydrogens has 1. Total = 4 + (4x1) = 8 valence electrons.
BONDING - POLAR VS NONPOLAR
Q26: Which of the following bonds is the most polar?
A. C-H | B. C-C | C. C-O | D. C-N
Correct Answer: C
Concept: Electronegativity increases across a period. Oxygen is more electronegative than Nitrogen, Carbon, or Hydrogen,
creating the greatest difference (delta) in electronegativity with Carbon.
CHEM 219 Module 2 - Page 4
