This comprehensive OCR A Level Chemistry PowerPoint lesson teaches students how to write electron configurations for atoms and ions using orbital diagrams, worked examples and practice activities.

Designed for OCR Chemistry A (H032/H432), Module 2: Foundations in Chemistry, this resource covers specification points 2.2.1© and 2.2.1(d) – Electron Structure. It is ideal for Year 12 students developing their understanding of how electrons are arranged within atoms and ions.

The lesson introduces electron configurations as representations of the arrangement of electrons within shells, sub-shells and atomic orbitals. Students learn the order in which orbitals fill according to increasing energy, including why the 4s sub-shell fills before the 3d sub-shell. The Aufbau principle, Hund’s rule and the Pauli exclusion principle are explored through clear explanations and diagrams.

Students practise writing full electron configurations using sub-shell notation, interpreting electron arrangements and constructing electrons-in-box diagrams to represent orbital occupancy and electron spin. Worked examples demonstrate electron configurations for elements across the periodic table, including the use of shorthand noble gas notation.

The PowerPoint progresses to electron configurations of positive and negative ions, explaining how electrons are lost or gained. Additional examples explore electron removal from the 4s sub-shell in d-block elements and the exceptional configurations of chromium and copper.

Throughout the lesson, structured activities, guided examples and knowledge checks provide opportunities to develop and assess understanding. Answers are included to support assessment for learning and independent practice.

Supplied as an editable PowerPoint presentation (.pptx), this resource is suitable for classroom teaching, revision and consolidation of electron configuration skills.

Last updated: November 2026.