Lesson Plan

Resources → Subject Notes → Chemistry → Notes
Lesson Plan
Grade: Date: 17/01/2026
Subject: Chemistry
Lesson Topic: Describe the giant covalent structure of silicon(IV) oxide, $mathrm{SiO}_2$
Learning Objective/s:
  • Describe the three‑dimensional network of SiO₄ tetrahedra in silicon(IV) oxide.
  • Explain how giant covalent bonding gives SiO₂ its high melting point, hardness and insulating properties.
  • Compare the SiO₂ structure with other giant covalent solids such as diamond and Al₂O₃.
  • Interpret a 3‑D diagram of SiO₂ and identify Si–O bond angles and coordination numbers.
  • Apply knowledge of SiO₂’s structure to predict its behaviour in common applications (glass, quartz).
Materials Needed:
  • Projector or interactive whiteboard for 3‑D animations.
  • Printed handout with SiO₂ tetrahedral diagram.
  • Ball‑and‑stick model kit to build a SiO₄ network.
  • Worksheet containing a comparison table of giant covalent solids.
  • Markers and whiteboard.
 Introduction:
Begin with a quick recall of the properties of metals, molecular solids and network solids, then ask students to predict why sand feels hard and melts at very high temperatures. Link this to prior knowledge of covalent bonds and state that by the end of the lesson they will be able to describe the SiO₂ network and explain its characteristic properties.
Lesson Structure:
  1. Do‑now (5'): Students list observable properties of common solids on the board; brief whole‑class discussion.
  2. Mini‑lecture (10'): Definition of giant covalent structures, SiO₂ empirical formula, tetrahedral coordination of Si and bridging O atoms.
  3. Visualisation (8'): Show a 3‑D animation of the SiO₂ network, highlight corner‑sharing SiO₄ tetrahedra and the 109.5° bond angle.
  4. Hands‑on modelling (12'): In pairs, students construct a small SiO₂ fragment using the ball‑and‑stick kit; teacher checks understanding of connectivity.
  5. Comparative analysis (10'): Complete a worksheet comparing SiO₂, diamond, Si, and Al₂O₃; discuss how structure influences melting point, hardness and conductivity.
  6. Formative check (5'): Exit‑ticket quiz – students write one sentence linking the SiO₂ network to one of its physical properties.
Conclusion:
Recap the key features of the SiO₂ giant covalent network and how they explain its high melting point, hardness and insulating nature. Collect the exit tickets to gauge understanding, and assign a short homework task: draw a labelled SiO₄ tetrahedron and list two real‑world applications of SiO₂ that rely on its structure.