• Explain how a permanent dipole can result in a polar bond. Week 8 • Describe electronegativity in terms of an atom attracting bonding electrons in a covalent bond. • Explain how a permanent dipole can result in a polar bond. © Pearson Education Ltd 2008 This document may have been altered from the original

Week 8 Non-polar bonds © Pearson Education Ltd 2008 This document may have been altered from the original

Week 8 The polar bond in H-Cl © Pearson Education Ltd 2008 This document may have been altered from the original

CCl4 is a non-polar molecule Week 8 CCl4 is a non-polar molecule © Pearson Education Ltd 2008 This document may have been altered from the original

Pauling electronegativity values across the Periodic Table Week 8 Pauling electronegativity values across the Periodic Table © Pearson Education Ltd 2008 This document may have been altered from the original

Range of bonding from covalent to ionic Week 8 Range of bonding from covalent to ionic © Pearson Education Ltd 2008 This document may have been altered from the original

Week 8 • Describe intermolecular forces in terms of permanent and instantaneous (van der Waals’ forces) dipoles. © Pearson Education Ltd 2008 This document may have been altered from the original

Permanent dipole–dipole forces between HCl molecules Week 8 Permanent dipole–dipole forces between HCl molecules © Pearson Education Ltd 2008 This document may have been altered from the original

Week 8 van der Waals’ forces © Pearson Education Ltd 2008 This document may have been altered from the original

Week 8 • Describe hydrogen bonding between molecules containing –OH and –NH groups. • Describe and explain the anomalous properties of water resulting from hydrogen bonding. © Pearson Education Ltd 2008 This document may have been altered from the original

The key features for hydrogen bonding Week 8 The key features for hydrogen bonding © Pearson Education Ltd 2008 This document may have been altered from the original

Hydrogen bonding in water Week 8 Hydrogen bonding in water © Pearson Education Ltd 2008 This document may have been altered from the original

The ice lattice is an open network of H2O molecules Week 8 The ice lattice is an open network of H2O molecules © Pearson Education Ltd 2008 This document may have been altered from the original

In DNA, three hydrogen bonds link C and G Week 8 In DNA, three hydrogen bonds link C and G © Pearson Education Ltd 2008 This document may have been altered from the original

In DNA, two hydrogen bonds link A and T Week 8 In DNA, two hydrogen bonds link A and T © Pearson Education Ltd 2008 This document may have been altered from the original

Week 8 Double helix in DNA © Pearson Education Ltd 2008 This document may have been altered from the original