Atomic Structure
Explore the fundamental building blocks of matter - from historical models to electron arrangements
Models of the Atom
Historical development from Dalton's billiard ball to the modern quantum model. Key experiments and scientists.
Structure of the Atom
Protons, neutrons, electrons - their properties, locations, and roles in the atom. Nucleus and electron cloud.
Atomic Number and Mass Number
Z and A notation, calculating protons, neutrons, and electrons. Nuclide notation for elements.
Isotopes
Atoms of the same element with different numbers of neutrons. Relative atomic mass calculations.
Electronic Configuration
Energy levels, orbitals, Aufbau principle, Pauli exclusion, Hund's rule. sp notation and orbital diagrams.
How to Use This Section
Start with Models of the Atom to understand the historical development of atomic theory. Then explore Structure of the Atom to learn about subatomic particles. Master Atomic Number and Mass Number before moving to Isotopes and finally Electronic Configuration. Each topic includes interactive games, quick checks, and quizzes to reinforce your understanding. All pages are mobile-friendly and work on all devices.
Study Tip
Create flashcards for each atomic model with the scientist, year, and key features. This helps memorize the timeline.
Exam Focus
Practice calculating protons, neutrons, and electrons from atomic and mass numbers. RAM calculations are frequently tested.
Practice
Use the interactive configuration builder to practice electron configurations for the first 20 elements until you can do them without help.
