1. Module 1 Intro

1.16. Page 5

Module 1: Lesson 3

Module 1—Chemical Foundations

Electronegativity

 

Read

 

This photograph is of Linus Pauling.

© Courtesy of the Dibner Library of the History of Science and Technology

Read “Electronegativity” on page 81 of your textbook. What sort of information did Linus Pauling use to develop his scale of electronegativities? Are electronegativities measurable values or a representation?

 

The “Reactivity of Elements” image illustrates the general reactivity trends on the periodic table, with the exception of the noble gases.

 

The general organization of the periodic table is shown The table has 18 columns. In the first column a downward arrow is shown with the word increase. In columns 3 through 6, an arrow points toward the left with the label word increase. In columns 11 through 14, an arrow points toward the right with the label word increase. In column 17 an arrow points upwards with the label word increase.

 

Try This

 

Identify where the highest and lowest values for electronegativity occur on the periodic table. Is the pattern for the reactivity of elements similar to the location of elements with high and low electronegativities?

 

Discuss

 

Can you suggest why there may there be a relationship between an element’s reactivity and its electronegativity? Share your thoughts with your teacher or your classmates.

 

In Module 2 you will learn more about how to use electronegativities as you study covalent bonds.

 

You’ll find the precise electronegativity of each element listed on the periodic table.

 

Read

 

How does electronegativity relate to the formation of ionic bonds? Read “Ionic Bonding” on page 83 of your textbook.

 

Self-Check

 

SC 5. Prepare a copy of the following table. Use the information on the periodic table to complete this table. Once complete, use the link to check your answers.

 

 

Watch and Listen

 

Earlier in Lesson 3 you watched video clips describing the formation of sodium chloride. This series of video clips will help you understand what influence the ionic bond between particles has on other ions. This results in the formation of a crystal lattice and a chemical ratio for sodium chloride.

 

Watch the Formation of NaCl video.

 



Find out why NaCl is a 1:1 ratio.

 



Watch this video, which illustrates the formation of magnesium oxide. Does magnesium oxide form a crystal lattice with a similar structure to a crystal of sodium chloride? Is the chemical ratio between the magnesium ion and oxide ion also similar to the ratio between sodium and chloride ions?