10-2 Chemistry Chapter 6 Review In addition to working through the questions below, review your notes and handouts, the end of section reviews, and the end of chapter review and questions. 6-1 Why do some atoms form covalent bonds? 1. Explain how a covalent bond forms between two atoms. 2. Describe the changes in energy, distance between nuclei, and stability as a covalent bond forms. (see Figures 6-4 and 6-5, p. 196) 3. Describe the difference between ionic and covalent bonds, and between polar and nonpolar bonds. 4. Describe the influence of electronegativity difference on bonding. 5. How are atomic orbitals (s,p,d,f) related to molecular orbitals? 6. What happens to the potential energy as two atoms approach one another? 7. What is the relationship between bond strength and bond length? (See table 6-1, p. 197) 8. What is the the meaning of bond energy? 9. Given a table of electronegativities (table 6-2, p. 198), how can you predict whether a bond would be considered nonpolar covalent, polar covalent, or ionic? Characterize the following bonds: K-Cl H-N F-F B-H 10.Describe the attractive forces and the repulsive forces that occur as two atoms move closer together. 11.What is meant by electron density? How does this relate to bond polarity and electronegativity? 6-2 How are molecules depicted? 12.Draw Lewis dot structures to show the arrangement of valence electrons among atoms in molecules and polyatomic ions. 13.Explain the difference between single, double, and triple bonds. 14.What is meant by a resonance structure? When are resonance structures required? 15.Name binary inorganic compounds using prefixes, roots, and suffixes. (Know prefixes from 1-10 [table 6-5]) 16.How is the Lewis structure of a polyatomic ion different from that of a molecule? 6-3 How are molecular shapes determined? 17.What is meant by the term electron domain? What can be counted as a single electron domain? 18.Describe the electron domain geometry around a central atom with 2, 3, or 4 electron domains. 19.For each electron domain geometry in question 18, describe (and name) the possible molecular geometries. 20.Interpret and draw 3-D representations for trigonal pyramid and tetrahedral molecules. 21.Predict the shape of a molecule based on its Lewis structure using VSEPR theory. 22.What is the difference between bond polarity and molecular polarity? How can you identify a polar molecule based on its molecular shape? 23.In VSEPR theory, what information about a central atoms do you need to know in order to predict the shape of a molecule? 24.What is the general relationship between molecular polarity and boiling point for different molecules? 25.Why does the presence of an unshared pair of electrons on nitrogen give ammonia (NH3) a trigonal pyramidal shape instead of a trigonal planar shape? 6-4 What forces exist between molecules? 26.Contrast ionic solids and covalent solids, in terms of melting point and boiling point. (See table 6-6, p. 219) 27.Describe the types of forces that exist between molecules (intermolecular forces). 28.Explain how a hydrogen bond differs from other polar-polar (or dipoledipole) forces. When can a hydrogen bond form? 29.What is the difference between intramolecular and intermolecular forces? 30.How are London forces different from dipole-dipole forces? How are London forces produced?