CHEMISTRY I:
GENERAL CHEMISTRY
Start from the ground up — atoms, electrons, configurations, and the patterns that make the periodic table tick.
ATOMS
What is an atom? Explore the building blocks of all matter and the scale of the atomic world.
PROTONS, NEUTRONS & ELECTRONS
Meet the three subatomic particles that make up every atom — and learn how charge holds them together.
ELEMENTS & THE PERIODIC TABLE
Discover how 118 elements are organised by atomic number, and how to read every cell in the table.
UNIT 1 QUIZ
15 questions covering atoms, subatomic particles, and the periodic table.
ELECTRON SHELLS
Electrons don't orbit randomly — they occupy specific energy levels called shells. Learn the rules that govern where electrons live.
VALENCE ELECTRONS
The electrons in the outermost shell are the ones that do all the chemistry. Learn how many each element has and why it determines almost everything about how it behaves.
ELECTRON CONFIGURATION
Subshell types, the Aufbau principle, Hund's rule, and interactive s/p/d/f orbital probability cloud animations.
ELECTRON CONFIGURATION NOTATION
Read and write full and noble-gas-abbreviated configurations. Explore the s/p/d block structure and practice with the interactive configuration explorer.
PERIODIC TRENDS
Atomic radius, ionization energy, and electronegativity — this is where the periodic table comes alive and the patterns hidden in the element blocks reveal themselves.
UNIT 2 QUIZ
15 questions covering electron shells, valence electrons, electron configuration, and periodic trends.