We continued our study of polarity, this time exploring how the polarity of molecules might impact our ability to smell the molecule.  Through the Lesson 45 PowerPoint, students learned that polar molecules are more likely to be detected by the nose as something with a scent although there are still polar molecules (like water) that do not smell.  Students worked in pairs to cut out the molecules in the molecules handout and used the molecules to complete the Lesson 45 Worksheet.  Students who would like to explore the polarity of molecules further are encouraged to visit the University of Colorado’s PhET molecule polarity simulation (or just click below).

Click to Run

Chapter 8 began with a lab designed to introduce students to the concept of polarity.  Students filled burets with water, vinegar, and vegetable oil and observed the path of the liquids in the absence or presence of an electrically charged wand.  The wand consisted of a long balloon rubbed vigorously on students’ hair to generate a static charge (build-up of electrons) on the balloon.  Students then observed how the negatively-charged balloon “pulled” the stream of water toward the balloon (pictured below along with the lab set-up).  Students worked through the Lesson 43 Worksheet while completing the lab.  After the lab, we reviewed the key vocabulary and concepts presented in the Lesson 43 PowerPoint.  For homework, students are assigned questions 4-6.