What you’ll learn5 learning objectivesChoose one objective for a focused lesson, or study the complete topic.1.3.1Emission spectra• Produced when electrons in excited states return to lower energy levels• Relationship: colour, wavelength, frequency, energy across electromagnetic spectrum• Continuous vs. line spectrumSyllabus objective1.3.2Hydrogen emission spectrum• Evidence for discrete energy levels• Energy transitions to n=1, n=2, n=3• Describe convergence at higher energies; series names are not assessedSyllabus objective1.3.3Main energy levels• Integer n, holds maximum 2n² electrons• Deduce maximum electrons in each main energy levelSyllabus objective1.3.4Sublevels• Main energy levels divided into s, p, d, f sublevels• Shapes: s orbital (spherical), three p orbitals (dumbbell)• Link sublevels to s, p, d, f blocks in the periodic tableSyllabus objective1.3.5Orbitals and electron spin• Each orbital holds 2 electrons of opposite spin• Aufbau principle, Hund's rule, Pauli exclusion principle• Electron configurations for atoms and ions up to Z=36• Use full, condensed, and orbital box diagrams; include Cr and Cu exceptionsSyllabus objective