Portage Learning CHEM 103 Module 4
Exam 2025:
Complete Verified Questions with 100%
Correct Answers & Detailed Explanations
General Chemistry I with Lab
Portage Learning
Updated for 2025 July 29, 2025
,Contents
1 Introduction 2
2 Questions and Answers with Explanations 2
3 Conclusion 19
1
, 1 Introduction
This document serves as a comprehensive study guide for the Portage Learning CHEM 103
Module 4 Exam 2025, covering electron configurations, periodic trends, chemical bonding,
Lewis structures, and molecular geometry. It includes exactly 100 verified questions,
each highlighted in dark royal red, with correct answers and detailed explanations to
ensure thorough understanding. The content has been refactored to eliminate unnecessary
jargon, focusing on clarity and relevance for effective exam preparation.
2 Questions and Answers with Explanations
The following 100 questions address the core topics of Module 4, with each question
highlighted in dark royal red for emphasis. Answers are verified, and explanations are
detailed to reinforce key concepts.
Question 1: What is the subshell electron configuration for the Fe (Iron, Atomic Number 26)
atom?
Answer: 1s² 2s² 2p� 3s² 3p� 4s² 3d�
Explanation: Iron has 26 electrons, filled in order of increasing energy (Aufbau
principle): 1s, 2s, 2p, 3s, 3p, 4s, 3d. The configuration is: - 1s²: 2 electrons - 2s²:
2 electrons - 2p�: 6 electrons - 3s²: 2 electrons - 3p�: 6 electrons - 4s²: 2 electrons -
3d�: 6 electrons Total: 2 + 2 + 6 + 2 + 6 + 2 + 6 = 26 electrons. The 4s subshell
fills before 3d due to its lower energy.
Question 2: Write the electron configuration for the S (Sulfur, Atomic Number 16) atom.
Answer: 1s² 2s² 2p� 3s² 3p�
Explanation: Sulfur has 16 electrons: - 1s²: 2 electrons - 2s²: 2 electrons - 2p�:
6 electrons - 3s²: 2 electrons - 3p�: 4 electrons Total: 2 + 2 + 6 + 2 + 4 = 16
electrons. The 3p� configuration places sulfur in the p-block, indicating its reactivity
as a nonmetal.
Question 3: Identify the valence electrons and their number for the P (Phosphorus, Atomic
Number 15) atom.
Answer: - Configuration: 1s² 2s² 2p� 3s² 3p³ - Valence electrons: 3s² 3p³ (5 valence
electrons)
Explanation: Phosphorus has 15 electrons: - 1s²: 2 electrons - 2s²: 2 electrons -
2p�: 6 electrons - 3s²: 2 electrons - 3p³: 3 electrons Total: 15 electrons. Valence
electrons are in the outermost shell (n=3), which includes 3s² and 3p³, totaling 5
valence electrons used in bonding.
Question 4: Provide the orbital diagram for the Ti (Titanium, Atomic Number 22) atom using
up and down arrows.
2
Exam 2025:
Complete Verified Questions with 100%
Correct Answers & Detailed Explanations
General Chemistry I with Lab
Portage Learning
Updated for 2025 July 29, 2025
,Contents
1 Introduction 2
2 Questions and Answers with Explanations 2
3 Conclusion 19
1
, 1 Introduction
This document serves as a comprehensive study guide for the Portage Learning CHEM 103
Module 4 Exam 2025, covering electron configurations, periodic trends, chemical bonding,
Lewis structures, and molecular geometry. It includes exactly 100 verified questions,
each highlighted in dark royal red, with correct answers and detailed explanations to
ensure thorough understanding. The content has been refactored to eliminate unnecessary
jargon, focusing on clarity and relevance for effective exam preparation.
2 Questions and Answers with Explanations
The following 100 questions address the core topics of Module 4, with each question
highlighted in dark royal red for emphasis. Answers are verified, and explanations are
detailed to reinforce key concepts.
Question 1: What is the subshell electron configuration for the Fe (Iron, Atomic Number 26)
atom?
Answer: 1s² 2s² 2p� 3s² 3p� 4s² 3d�
Explanation: Iron has 26 electrons, filled in order of increasing energy (Aufbau
principle): 1s, 2s, 2p, 3s, 3p, 4s, 3d. The configuration is: - 1s²: 2 electrons - 2s²:
2 electrons - 2p�: 6 electrons - 3s²: 2 electrons - 3p�: 6 electrons - 4s²: 2 electrons -
3d�: 6 electrons Total: 2 + 2 + 6 + 2 + 6 + 2 + 6 = 26 electrons. The 4s subshell
fills before 3d due to its lower energy.
Question 2: Write the electron configuration for the S (Sulfur, Atomic Number 16) atom.
Answer: 1s² 2s² 2p� 3s² 3p�
Explanation: Sulfur has 16 electrons: - 1s²: 2 electrons - 2s²: 2 electrons - 2p�:
6 electrons - 3s²: 2 electrons - 3p�: 4 electrons Total: 2 + 2 + 6 + 2 + 4 = 16
electrons. The 3p� configuration places sulfur in the p-block, indicating its reactivity
as a nonmetal.
Question 3: Identify the valence electrons and their number for the P (Phosphorus, Atomic
Number 15) atom.
Answer: - Configuration: 1s² 2s² 2p� 3s² 3p³ - Valence electrons: 3s² 3p³ (5 valence
electrons)
Explanation: Phosphorus has 15 electrons: - 1s²: 2 electrons - 2s²: 2 electrons -
2p�: 6 electrons - 3s²: 2 electrons - 3p³: 3 electrons Total: 15 electrons. Valence
electrons are in the outermost shell (n=3), which includes 3s² and 3p³, totaling 5
valence electrons used in bonding.
Question 4: Provide the orbital diagram for the Ti (Titanium, Atomic Number 22) atom using
up and down arrows.
2
