Introduction to Atomic Structure
Start with the big picture
An element is identified by its atomic number, while its mass number counts protons and neutrons; together these values help distinguish isotopes and determine neutron count. The chapter then traces models of the atom, from Rutherford’s evidence for a compact nucleus to Bohr’s account of hydrogen spectra. Quantum concepts describe electrons through wavefunctions and probability, with quantum numbers specifying electron states. Orbital shapes and energies provide a framework for electron configurations, governed by the Pauli exclusion principle, Aufbau principle, and Hund’s rule. Finally, shielding and effective nuclear charge connect atomic structure to periodic trends such as ionization energy, electron affinity, and electronegativity, as well as transitions that produce atomic spectra.
What you'll learn
- Relate atomic number, mass number, neutron count, isotopes, and ion formation.
- Outline how Rutherford’s and Bohr’s models contributed to atomic theory.
- Explain electron probability, orbitals, quantum numbers, and the uncertainty principle.
- Apply the Pauli, Aufbau, and Hund principles to electron configurations.
- Connect shielding and effective nuclear charge with periodic properties.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
