Chapter 8 Covalent Bonding 8.2 The Nature of Covalent Bonding 8.1 Molecular Compounds 8.2 The Nature of Covalent Bonding 8.3 Bonding Theories 8.4 Polar Bonds and Molecules Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Single Covalent Bond: atoms held together by sharing one pair of electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Structural Formula: represents the covalent bonds as dashes and shows the arrangement of covalently bonded atoms. H:H H-H Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Unshared pair: pair of valence electrons that is not shared between atoms, also known as a lone pair (non-bonding pair). In F2, each fluorine atom has three unshared pairs of electrons. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Double Covalent Bond: a bond that involves two shared pairs of electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Triple Covalent Bond: a bond formed by sharing three pairs of electrons Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Bond Dissociation Energies Bond Dissociation Energy: energy required to break the bond between two covalently bonded atoms. Bond Bond Dissociation Energy (kJ/mol) Bond Length (pm) C C 347 154 C = C 657 133 908 121 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Drawing Lewis Dot Structures: Determine # of valence electrons. Determine # of “octet” electrons. *Note*– Hydrogen gets 2 # bonds = (# valence e- - # octet e-) / 2 Arrange atoms with # bonds from step 3. Hydrogen & halogens bond one time Group 6A elements bond 2 times Group 5A elements bond 3 times Carbon always bonds 4 times Add electron pairs until all atoms have the correct number of electrons around them Recheck your answer. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The Octet Rule in Covalent Bonding Draw Lewis Dot Structures for each molecular compound: SiO2 HCl H2O HCN Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Exceptions to the Octet Rule Molecules whose total number of valence electrons is an odd number. 2. Boron wants 6 electrons for neutral molecules. 3. Phosphorus and sulfur expand the octet to 10 or 12 electrons. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

The ozone molecule has two possible electron dot structures. Resonance Resonance structures: structures that occur when it is possible to draw two or more valid electron dot structures that have the same number of electron pairs for a molecule or ion. The ozone molecule has two possible electron dot structures. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

http://www. pbslearningmedia. org/resource/ess05. sci. ess. watcyc http://www.pbslearningmedia.org/resource/ess05.sci.ess.watcyc.antarctica/a-hole-in-the-sky/ http://www.pbslearningmedia.org/resource/ess05.sci.ess.watcyc.ozonehole/ozone-hole/ Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

What is ozone and what causes its depletion? What are the benefits and disadvantage of ozone? What are the implications of a depleted ozone layer? Create a timeline of major milestones related to ozone depletion. What challenges do you think arise when confronting an emerging environmental issue? What are other examples of humans affecting our environment? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. .

END OF 8.2 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.