Atomic Structure and Periodicity of Elements - Chemistry (Undergraduate Foundation)

This course provides a complete guide to the modern theory of the atom. It traces the historical development of atomic models, from Dalton's foundational theory to the modern understanding of electronic structure. The material covers subatomic particles, the contributions of Thomson and Rutherford, the Bohr model, wave-particle duality, and culminates in a full treatment of electronic configuration and its direct relationship to the periodic trends of the elements. A command of atomic theory is the absolute foundation of modern chemistry. The electronic structure of the atom dictates all chemical properties and bonding behaviour. This knowledge is essential for understanding the periodic table, predicting chemical reactions, and is the prerequisite for the study of spectroscopy, materials science, and quantum mechanics. By the end of this course, you will be able to describe the historical evolution of atomic theory. You will also be able to explain the atom's structure, including the roles of protons, neutrons, and electrons. You will determine the electronic configuration of any element and use periodic trends to predict and justify atomic properties like size, ionisation potential, and electronegativity. This course is for students who have completed an introductory chemistry course. It is a mandatory prerequisite for any student pursuing a degree in chemistry, chemical engineering, materials science, or physics.

9 hrs

Enrolment valid for 12 months

This course is also part of the following learning track. You may join the track to gain comprehensive knowledge across related courses.

CHM 101: General Chemistry I

This learning track delivers the complete NUC CCMAS curriculum for General Chemistry I. It is a comprehensive programme designed to build a robust, university-level foundation in modern chemistry. The track systematically covers all essential topics, from atomic theory, chemical bonding, and the states of matter, to the quantitative principles of stoichiometry, equilibrium, thermodynamics, and kinetics. This programme is for first-year undergraduates in science, technology, engineering, and mathematics (STEM) faculties who are required to take CHM 101. It is also essential for any student or professional globally who needs a rigorous and complete foundation in first-year university chemistry for further study or career development. This track delivers a full skill set in chemical theory and quantitative problem-solving. Graduates will be able to determine molecular structures, calculate reaction quantities, analyse the energetics and rates of reactions, and solve complex equilibrium problems. This programme provides the non-negotiable prerequisite knowledge for all subsequent chemistry courses and for any degree in the physical sciences, engineering, or medicine.

Course Chapters

1. Introduction

This chapter provides the roadmap for the course. It outlines the progression from early atomic theories to the modern understanding of atomic structure and its direct relationship to the periodic table. Key learning objectives include: understanding the overall course structure and appreciating the historical and experimental development of atomic theory.

Concept Overviews

1 Lesson

6:35

2. Early Atomic Models

This chapter traces the origin of atomic theory, starting with the empirical laws that led to Dalton's foundational model. It then covers the pivotal discovery of the electron, the first experimental proof that the atom is divisible, which forced the initial theory to evolve. Key topics include the laws of chemical combination, Dalton's atomic postulates and their critical shortcomings, and the experiments by Thomson and Millikan that discovered and characterised the electron, leading to the 'plum pudding' model.

Concept Overviews

6 Lessons

56:53

3. The Nuclear Model

This chapter covers the development of the nuclear atom, from Rutherford's definitive gold foil experiment to Chadwick's discovery of the neutron. It establishes the modern planetary model of the atom and immediately addresses its critical failure, demonstrating why classical physics is insufficient. Key topics include the experimental evidence for the nucleus, the discovery of the neutron, the shortcomings of Rutherford's classical model, and the fundamental properties of protons, neutrons, and electrons.

Concept Overviews

5 Lessons

39:13

Problem Walkthroughs

2 Lessons

31:50

4. Bohr's Model

This chapter details Niels Bohr's model, the first attempt to solve the failures of the classical nuclear atom using quantum theory. Understanding this transitional model is critical to grasping the full conceptual leap to modern quantum mechanics. Topics include: Bohr's postulates, explaining hydrogen's emission spectrum, energy level calculations, and the model's ultimate shortcomings.

Concept Overviews

3 Lessons

28:54

Problem Walkthroughs

1 Lesson

19:18

5. Wave-Particle Duality

This chapter details wave-particle duality, the principle that all matter has wave properties. This concept explains the failure of Bohr's fixed orbits and establishes the necessary theoretical foundation for the modern quantum mechanical model of the atom. Key topics include: De Broglie’s wave hypothesis, applying the de Broglie relation (λ = h/mv), and calculating the wavelength of moving particles based on their mass and velocity.

Concept Overviews

1 Lesson

4:04

Problem Walkthroughs

2 Lessons

16:27

6. The Quantum Model

This chapter introduces the modern quantum mechanical model, replacing Bohr's flawed orbits with probabilistic orbitals. Mastery of this model is non-negotiable, as it provides the definitive framework for describing electron behaviour and predicting all chemical properties. Key topics include: the four quantum numbers, defining orbital shapes (s, p, d, f) and their spatial orientation, and applying the Aufbau principle, Pauli exclusion, and Hund's rule to write correct electronic configurations.

Concept Overviews

6 Lessons

1:09:59

Problem Walkthroughs

1 Lesson

14:40

7. Periodicity

This chapter connects electronic configuration to the predictable, repeating properties of the elements. Mastery of these trends is the practical application of atomic theory and is essential for predicting chemical behaviour, bonding, and reactivity. Key topics: trends in atomic radii, ionisation energy, electron affinity, and electronegativity; and the classification of elements as metals, non-metals, and metalloids.

Concept Overviews

7 Lessons

1:53:07

8. Conclusion

This concluding chapter summarises the key concepts of atomic theory. It reinforces the understanding of atomic structure and its connection to the periodic properties of the elements. This summary prepares the student for the next course, 'Chemical Bonding and Molecular Geometry', where electronic structure is used to predict how atoms form molecules.

Concept Overviews

1 Lesson

19:15