This PowerPoint lesson explains the bonding triangle model, helping IBDP Chemistry students classify substances using electronegativity and predict physical properties. Designed for first assessment 2025, it develops a deeper understanding of bonding as a continuum between ionic, covalent and metallic character.
The bonding triangle is a model used to represent how chemical bonds vary depending on the electronegativity of the elements involved. Rather than viewing ionic, covalent and metallic bonding as completely separate categories, this lesson shows how substances lie along a spectrum. Students are introduced to the historical Van Arkel–Ketelaar triangle and learn how modern versions use electronegativity (χ) values from the IB data booklet to position compounds quantitatively.
Step-by-step worked examples include Na, H₂, NaCl, SiO₂ and MgO, demonstrating how to calculate electronegativity difference (Δχ), determine average electronegativity, and interpret bonding character. The link between position in the triangle and physical properties such as melting point, brittleness, lattice structure and conductivity is clearly developed. Students learn why substances near the ionic or metallic regions tend to have high melting points and lattice structures, while those near the covalent region often show molecular behaviour.
The lesson also highlights limitations of the model, including its restriction to elemental substances and binary compounds, and embeds Nature of Science discussion about how scientific models evolve.
Starter activities, structured explanations, worked calculations and practice questions are included, making this resource ideal for teaching, consolidation or revision.
File type included: PowerPoint (.pptx)
Last updated: January 2026 – electronegativity examples refined and model limitations clarified in line with the 2025 IB Chemistry syllabus.
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BUNDLE S2.4 From Models to Materials, SL & HL (IBDP Chemistry)
This comprehensive PowerPoint bundle covers S2.4 From Models to Materials for IBDP Chemistry (first examination 2025), linking bonding models to real-world materials and properties. It provides a clear, structured sequence of lessons to help students understand how bonding and structure determine the behaviour and uses of materials. From models to materials focuses on applying bonding theories (ionic, covalent and metallic) to explain the properties and uses of substances. Rather than treating bonding as separate categories, students explore bonding as a continuum, using tools such as the bonding triangle and electronegativity to predict material behaviour and properties . This bundle includes 6 fully editable PowerPoint (.pptx) lessons designed for teaching, revision or flipped learning: • Properties of materials and bonding as a continuum • The bonding triangle and use of electronegativity to classify substances • Alloys, including structure, properties and real-world applications • Introduction to polymers and structure–property relationships • Addition polymers, including mechanisms and naming • Condensation polymers (HL extension), including polyesters and polyamides Each lesson includes retrieval starters, key definitions, worked examples, and exam-style practice questions. Students develop skills in classifying bonding, predicting physical properties (e.g. melting point, conductivity, flexibility), and linking chemistry to applications such as materials design, sustainability and fast fashion. This resource is ideal for IB teachers delivering both SL and HL content, supporting conceptual understanding while preparing students for exam-style questions and real-world application of chemistry. Files included: • 6 × editable PowerPoint (.pptx) lessons Last updated: 2026 – improved explanations of bonding continuum, enhanced application tasks, and stronger links to real-world materials and sustainability contexts.
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BUNDLE S2.4 From Models to Materials SL Content (IBDP Chemistry)
This bundle of PowerPoints covers IBDP Chemistry SL only content of Topic 2.4: From Models to Materials (first examination 2025) and provides a complete, structured sequence of lessons linking bonding models to real-world materials. Designed specifically for the updated IB Diploma Programme specification, this resource helps students move from abstract bonding theory to explaining and predicting material properties. Topic 2.4 focuses on how ionic, covalent and metallic bonding models can be used to understand the physical properties of substances and materials. Across the bundle, students explore bonding as a continuum (using the bonding triangle and electronegativity data), properties of materials, metallic bonding, alloys, polymers and addition polymers. Clear worked examples and structured tasks guide learners in applying models to explain melting point, electrical conductivity, hardness, malleability, brittleness and flexibility. The lessons include: • Starter activities (retrieval and true/false questions) • Clear definitions of key terms (e.g. flexibility, malleability, alloy, electronegativity) • Bonding triangle classification using electronegativity values • Structured explanations linking structure → bonding → properties • Alloy structure (substitutional and interstitial) and phase diagrams • Polymer structure and addition polymerisation • Practice questions and discussion tasks Each file is provided as a fully editable .pptx PowerPoint, allowing you to adapt slides to your class context. This bundle is ideal for teaching, revision, or consolidation of SL 2.4 content and supports conceptual understanding, exam-style thinking and the IB Nature of Science emphasis on models and their limitations. It can be used as a full teaching sequence or as standalone lessons within your DP Chemistry course.
£7.00
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