Students will learn the Lewis model of chemical bonding. Students will draw simple Lewis structures for a variety of covalently bonded molecules.
Standard 1- Basic operations and concepts
Standard 3- Technology productivity tools
Standard 4- Technology communications tools
Standard 5- Technology research tools
Standard 1- The student accesses information efficiently and effectively
Standard 2- The student evaluates information critically and competently
Standard 3- The student uses information accurately and creatively
Reside at the heart of the discipline
Interaction of matter and energy
Visualization of chemical bonding
Represents a big idea having enduring value beyond the classroom:
Things that appear random are predictable.
Bonds are what hold our bodies together.
Require uncoverage, meaning that misconceptions need to be identified and clarified:
Chemical bonds are energetic interactions not physical connections.
Though electrons are represented as stationary dots, they are neither particles nor stationary.
Offer potential for engaging students:
Why are trees and people are different even though they're made of the same stuff?
Lewis structures can be used to predict chemical formulas and molecular geometries. Also Gilbert Lewis' birthday is October 23rd. MOLE DAY!
Exit cards, journal responses and a quiz will each be utilized in this unit. Exit cards will be used after the introduction of a new concept so that the instructor may evaluate the need for reteaching or redirecting the students. In journal responses the teacher should look for statements that would indicate an incorrect understanding or misconception. Students will construct and present a 3-dimensional model of a compound. For the quiz the student will construct a Lewis diagram for five simple covalent compounds and describe the polar character of the bonds. The bond polarity makes reference to the previous unit `Electronegativity Electron Affinity and Bond Types' which can be found at -web site here-
Review electron placements in the atom with a focus on valence electrons and their pattern on the periodic table. ( www.chemicalelements.com/ )
Introduce the topic of Lewis structures as a short hand method for writing atomic diagrams. Since electrons like to be paired, both atoms can have pairs of electrons if they share with each other. This is the basis for chemical bonding as represented by Lewis structures.
Practice with Lewis structures. Students will have opportunities to develop Lewis structure skills with molecules supplied by the teacher, with internet resources and with molecules that students find represented in their homes.
Creative and Critical Thinkers
Ethical and Responsible Workers