Lesson 5: 1.5 Atomic Structure and Electron Configuration

If atoms cannot be observed directly, how do we model the distribution of their electrons?
How does Coulomb’s Law explain the difference in energy between core and valence electrons?

Coulomb’s Law
Shell Model, Subshell
Electron Configuration
Core Electrons
Valence Electrons
Aufbau Principle

Learning Objective 1.5.A; Suggested Skill 1.A (Models and Representations)

Introduces the internal structures of the atom, focusing heavily on the shell model and quantum mechanics via electron configurations. Coulomb’s Law (F = k(q1q2/r^2) is established as the foundational governing principle to explain electrostatic attractions and the ionization energy required to remove electrons. Note: Quantum numbers (n, l, ml, ms) are excluded.

Support: Use a color-coded periodic table blocks template (s, p, d, f) to assist students in tracking the sequence of the Aufbau principle.
Extension: Ask students to qualitatively apply Coulomb's law to explain why removing a core electron requires significantly more energy than removing a valence electron from the same atom.

Ask students to write out the full and noble gas shorthand ground-state electron configurations for both neutral atoms and transition metal ions (emphasizing loss of s electrons first).