Structure 1.3 Electron configurations 
Structure 1.3.1 
Understandings:
  • Emission spectra are produced by atoms emitting photons when electrons in excited states return to lower energy levels.
Learning outcome(s):
  • Qualitatively describe the relationship between colour, wavelength, frequency and energy across the electromagnetic spectrum.
  • Distinguish between a continuous and a line spectrum.
This video covers the electromagnetic spectrum and the relationship between energy, frequency and wavelength. ​
This video covers the difference between a continuous spectrum and a line spectrum. ​
Structure 1.3.2 
Understandings:
  • The line emission spectrum of hydrogen provides evidence for the existence of electrons in discrete energy levels, which converge at higher energies.
Learning outcome(s):
  • Describe the emission spectrum of the hydrogen atom, including the relationships between the lines and energy transitions to the first, second and third energy levels.
This video covers the emission spectrum of hydrogen. 
Structure 1.3.3 and 1.3.4
Understandings:
  • The main energy level is given an integer number, n, and can hold a maximum of 2n2 electrons (1.3.3).
  • A more detailed model of the atom describes the division of the main energy level into s, p, d and f sublevels of successively higher energies (1.3.4).
Learning outcome(s):
  • Deduce the maximum number of electrons that can occupy each energy level (1.3.3).
  • Recognize the shape and orientation of an s atomic orbital and the three p atomic orbitals (1.3.4).
This video covers atomic orbitals and sub-levels. 
Structure 1.3.5
Understandings:
  • Each orbital has a defined energy state for a given electron configuration and chemical environment, and can hold two electrons of opposite spin.
  • Sublevels contain a fixed number of orbitals, regions of space where there is a high probability of finding an electron.
Learning outcome(s):
  • Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to deduce electron configurations for atoms and ions up to Z = 36.
Additional notes: 
  • Full electron configurations and condensed electron configurations using the noble gas core should be covered.
  • Orbital diagrams, i.e. arrow-in-box diagrams, should be used to represent the filling and relative energy of orbitals.
  • The electron configurations of Cr and Cu as exceptions should be covered.
The following two videos cover how to write electron configurations for atoms with atomic numbers 1 to 36.
This video covers the electron configurations of ions.