Unit · year 1
CU-101 · Atomic Structure & Periodicity
Threads quantum · structure6 results
Where chemistry begins: the quantum atom, and why the periodic table has the shape it does.
Results in this unit
T-001
The Bohr model of hydrogen
Quantised electron orbits give energy levels E_n = -13.6/n^2 eV.
T-002
The Rydberg formula
Every hydrogen spectral line from a single expression in 1/n^2.
T-003
Quantum numbers and atomic orbitals
Four quantum numbers label every electron in an atom.
T-004
The building-up principle
Aufbau order, Hund's rule and the Pauli principle fix ground-state configurations.
T-005
Periodic trends
Effective nuclear charge explains atomic size and ionisation energy across the table.
T-006
Ionisation and the photoelectric effect
Electrons are ejected only above a threshold photon energy.