After learning about the concepts of electronegativity and polarity in yesterday’s lesson, students learned that scientist Linus Pauling assigned electronegativity values to individual atoms as a measure of how strongly an atom attracts electrons (click here for a deeper dive into how he calculated electronegativity). Although not used in class, the Lesson 44 PowerPoint is provided here as a resource and includes a copy of the periodic table with electronegativity values for each element. It also explains the difference in electronegativity between covalent bonds (0.5 and less), polar covalent bonds (between 0.5-2.1), and ionic bonds (greater than 2.1).
Students who finish the work early had time to complete yesterday’s Lesson 43 worksheet and Monday’s Polarity and Intermolecular Forces Gizmo. Students who are fully caught up have the opportunity to investigate vectors and may earn bonus credit for completing one or both vector-related Gizmos.
Notes from class:
Want more information about dipoles from yesterday’s lesson? Read about how dipole moments are calculated.
Wondering how scientists measure the electronegativity of atoms? One new technique involves atomic force microscopy. Read more: Electronegativity of a single atom scrutinized under the microscope.
The Pauling scale of electronegativity was updated in a paper published a year ago (January 2019, Journal of the American Chemical Society). Read a summary of the work: New scale for electronegativity rewrites the chemistry textbook. Want more? Take a look at the supporting data for the journal article.
- Read Lesson 44 in the textbook. Login via the Sapling website and enter your username and password.
- Write notes for Lesson 44 and work through the practice problems at the end of Lesson 44
- Please ask questions about anything from Lesson 44 you do not yet fully understand.