*Topic 3 Polarity

​As you work through this presentation, please fill out your notes sheet and answer the questions as you go.

Recall: The position of an element on the periodic table determines its electronegativity.

Multiple Select

A molecule is polar when.... (Choose all that apply)

• When the central atom has no lone pairs

• When the central atom has 1 or more lone pairs

• When the molecule has 1 or more polar bonds

Multiple Choice

What is the reason the shared electrons are held closer to fluorine in the polar molecule H-F?

• Fluorine has a lower electronegativity

• Hydrogen has a higher electronegativity

• Fluorine has a higher electronegativity

• Both atoms share electrons equally

Multiple Choice

This is an example of a __________ bond.

• non-polar covalent
• polar covalent
• ionic
• metallic

Multiple Choice

True or False: All diatomic molecules are nonpolar.

• True

• False

Multiple Choice

What is the primary factor that determines whether a molecule is polar or nonpolar?

• The size of the molecule

• The molecular weight

• The shape of the molecule and the distribution of charge

• The number of electrons

Multiple Choice

What are the general rules to determine if a molecule is polar or nonpolar?

• Asymmetrical molecules are always nonpolar

• Asymmetrical molecules are always polar

Take your time working through these examples! They will take you step by step on how to determine the polarity of molecules.

Draw the Lewis Diagram on your notes sheet on your own first, then click next to check if you drew them correctly!

Multiple Choice

Based on the two Lewis Structures you drew, which molecule is Polar?

• HF

• H₂

Draw the Lewis Diagram on your notes sheet on your own first, then click next to check if you drew them correctly!

Multiple Choice

Based on the two Lewis Structures you drew, which molecule is Polar?

• CO₂

• COS

Draw the Lewis Diagram on your notes sheet on your own first, then click next to check if you drew them correctly!

Recall: Did having a lone pair of electrons on the central atom make the molecule polar or nonpolar?

Multiple Choice

H₂O and NH₃ have at least one lone pair of electrons on the central atom, so the molecules must be...

• Polar

• Nonpolar

Draw the Lewis Diagram on your notes sheet on your own first, then click next to check if you drew them correctly!

Multiple Choice

Which molecule is asymmetrical and therefore polar?

• CH₄

• CH₃Cl

Review Questions

Labelling

Label the molecule accordingly.

Drag labels to their correct position on the image

Higher electronegativity

Lower electronegativity

Multiple Choice

The electrons in a polar covalent molecule are shared...

• Evenly

• Unevenly

• Electrons are not shared

• None of the Above

Multiple Choice

Classify the following molecule.

• polar

• nonpolar

Multiple Choice

Classify the following molecule.

• polar

• nonpolar

Multiple Choice

Why is the molecule nonpolar?

• There are lone pairs on the central atom.

• There are different types of elements bonded to the central atom.

• There are no lone pairs on the central atom and all of the atoms bonded to the central atom are the same. (symmetrical)

Multiple Choice

Classify the following molecule.

• polar

• nonpolar

Multiple Choice

Why is the molecule polar?

• There is a lone pair on the central atom, creating a negative side to the molecule.

• There are different types of elements bonded to the central atom.

• There are no lone pairs on the central atom and all of the atoms bonded to the central atom are the same.

Poll

How confident do you feel about this topic now?

• Very confident
• Somewhat confident
• Not confident