P206: Valence Pictionary: An activity for formal charge

Author: Keir H. Fogarty and Elodie E. Marlier, Saint Olaf College, USA

Co-Author:

Date: 8/4/14

Time: 10:35 AM10:55 AM

Room: ASH 2302

Related Symposium: S23

General chemistry students overemphasize the octet rule in drawing Lewis structures. To remedy this problem, an activity was developed to encourage students to use formal charge as a key ingredient in Lewis structure formulation. The activity is modeled after Pictionary; a student has a card depicting a Lewis structure with an unknown central atom, “A.” A blurb on the card identifies acceptable central atoms for A. This student draws the Lewis structure and other students use formal charge to identify the central atom. In a variation of the game, students identify the hybridization and geometry around the central atom. This one hour activity involves groups of 3-6. While designed for general chemistry, this activity builds a foundation for organic chemistry, as it helps students think about hybridization and resonance structures. Students state that this activity solidifies their understanding of formal charge and their ability to draw Lewis structures.