Description
Atoms share or transfer electrons with other atoms to form stable compounds, diatomic gases, or polyatomic ions. Lewis dot structures are models to represent the number of electrons in an atom’s outermost energy level. Students use a systematic approach to master key concepts of Lewis dot structures and the octet rule, then extend that knowledge to the structures for covalent compounds and polyatomic ions. Student illustrations, combined with their physically building molecular model representations, help them answer the driving question: Why do molecules with the same molecular formulas have different geometric shapes?
Time Requirement
Total, 95 minutes. Teacher prep, 5 minutes. Pre-lab activity, 40 minutes. Investigation, 40 minutes. Assessment, 10 minutes.
Digital Resources
Includes 1-year access to digital resources that support 3-dimensional instruction for NGSS. Digital resources may include a teacher manual and student guide, pre-lab activities and setup videos, phenomenon videos, simulations, and post-lab analysis and assessments.
Crosscutting Concepts
Structure and Function
Science and Engineering Practices
Obtaining, Evaluating, and Communicating Information
Learning Objectives
- Write Lewis dot structures for elements, molecules, and polyatomic ions.
- Use VSPER theory to predict the geometry of molecules from Lewis structures and use illustrations or molecular models to support their prediction.
- Construct 3D models with a molecular model set and draw that 3D representation on paper.
Prerequisite Knowledge and Skills
Students should be familiar with covalent and ionic bonding; be able to read and write electron configurations for main group elements in groups 1, 2, and 13–18; and should understand Pauli’s Exclusion Principle and Hund’s Rule. They should also have a basic understanding of geometric shapes.