Courses
Teacher-curated, self-paced courses. Looking for a guided sequence through a full topic? See Learning Paths.
3 courses
The Quantum Model and Electron Configurations
Chemistry · High School (11–12) · Quantum Mechanical Model of the Atom, Electronic Configuration and Valency
FreeCh 2 · 3/4
Bohr's circles work for hydrogen, and they fail for every other atom. The better picture is a cloud of probability. In this course we meet the waves of matter, the uncertainty principle, the four quantum numbers and the shapes of orbitals. Then we use three rules to write the electron configuration of any atom, and we explain the odd cases, such as chromium and copper.
4Lessons12Problems2Python Labs1Question Set1Mock Test
Patterns Across Periods and Down Groups
Chemistry · High School (9–10), General · Periodic Trends, Electronic Configuration and Valency
FreeCh 9 · 2/4
Why does carbon make four bonds and oxygen two? Why is a sodium atom bigger than a chlorine atom? In this course we find the valency, the size, the metallic character and the oxides of the elements, and how they change across a period and down a group.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Electron Shells, Valency and Atomic Number
Chemistry · High School (9–10), General · Electronic Configuration and Valency, Isotopes and Isobars
FreeCh 4 · 2/3
Electrons sit in shells, and the outer shell decides how an atom behaves. Here we learn the rules for filling the shells, how to find the valency of an atom, and how the atomic number and the mass number tell us the particles in an atom.
3Lessons10Problems2Python Labs1Question Set1Mock Test