Chemical Bonding revised

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Slide 1

Unit 2: Bonding

Slide 2

Overview

Covalent Bonding

Ionic and Metallic Bonding

Electronegativity

Molecular Shape

Polarity

Ionic Crystals

Network Solids

Intermolecular Forces

Slide 3

Covalent Bonding

Bonds between atoms are formed through the sharing of electrons

Covalent bonds form between two non-metal atoms through sharing of pairs of electrons

Atoms have a “desire” to have their outer energy levels filled (Octet Rule)

Covalent bonding can be represented with Lewis Dot Diagrams

Slide 4

Lewis Dot Diagrams

Lewis Dot Diagrams show the sharing of electrons between atoms and where the bonds form

atoms share electrons to fill their outer energy levels (8 electrons in their outer shell)

The exception is hydrogen (2 electrons in its outer shell)

Slide 5

Lewis Dot Diagrams for Hydrogen and Chlorine Gas

The first row shows the atoms before they are bonded

The second row shows the sharing of electrons to fill the outer energy level

The third row has circles around the electrons to show those that belong to each atom. Where the circles overlap represents a covalent bond

Slide 6

Multiple Bonds

Double and triple bonds can form between atoms in order to fill the outer energy level

This occurs when two atoms share more than one pair of electrons

Slide 7

Multiple Lewis Structures

Some molecules can have more than one possible Lewis structure, usually when one single bond and one double bond can be exchanged within the rules of drawing Lewis structures

Example of SO2 (g)

Slide 8

Structural Diagrams

Lewis Diagrams can be converted to structural diagrams for convenience

Structural diagrams use lines to represent a bond, or a pair of electrons, but it does not show lone electron pairs

Example: Chlorine Gas

Slide 9

Lewis Dot Diagram Worksheet

Using the rules for drawing Lewis dot diagrams, complete the worksheet (LDD and structural)

For extra practice, try the Lewis Structures Thought Lab

Slide 10

Stereochemistry – The Structures of Molecular Compounds