1. Covalent Compounds Chapter 6 6-1 Covalent Bonds

2. Covalent Bond The sharing of electrons between atoms Forms a molecule To have stable (filled) orbitals

3. Diatomic Molecules Formed by covalent bond between two atoms of the same element

4. Molecular Orbital The space in which the shared electrons move

5. Energy and Stability Un-bonded atoms (except noble gases) have low stability and high potential energy Energy is released when they form a bond

6. Attraction and Repulsion When balanced, a covalent bond forms

7. Bond Length The distance between two bonded atoms at their minimum potential energy

8. Bond Energy The energy required to break a bond kJ/mol

9. Electronegativity and Covalent Bonding Electronegativity - How much an atom attracts electrons Atoms share electrons equally or unequally – depending on the electronegativity of the atoms

10. Nonpolar Covalent Bonds Electrons are shared equally

11. Polar Covalent Bonds Atoms share electrons unequally Have different electronegativities

12. Dipole Molecule One end is partial positive and the other end is partial negative Hydrogen and fluorine

13. Polarity and Bond Strength The greater the difference in electronegativity, the greater the polarity, and the greater the bond strength ------------------ Bond Strength ------------------ 

14. Determining Bond Types Differences in Electronegativity of the atoms

15. Metallic Bonds Results from the attraction between metal atoms and the surrounding sea of electrons

16. Properties of Substances Depends on Bond Type Metallic – good conductors Ionic – strong bonds, high melting point See table 3 page 197

17. Drawing and Naming Molecules Section 6-2

18. Valence Electrons

19. Lewis Electron- Dot Structure s

20. Octet Rule

21. Lewis Structures Model Covalently Bonded Molecules

22. Unshared (lone) Pairs Not part of the bond

23. Single Bond The shared pair Can be shown by a dash

24. Lewis Structures for Polyatomic ions Ammonia Ammonium ion enclose in brackets w/ + charge

25. Double Bonds Share 4 (2 pair) electrons Carbon, oxygen, nitrogen

26. Triple Bonds Share 6 (3 pair) electrons Nitrogen and Carbon

28. Naming Covalent Compounds Similar to Ionic bonds -ide suffix Prefixes indicating number On first element, only if more than one

29. Molecular Shapes Section 3

30. Determining Molecular Shapes The shape helps determine the molecules physical and chemical properties

31. Linear Shape “In a line” Molecules made of 2 atoms H 2 or CO

32. VSEPR Theory Pronounced “vesper” A model used to predict the shape of a molecule Valence Shell Electron Pair Repulsion Theory Based on the idea that valence electrons repel each other

33. Linear Shape The shared pairs repel each other and remain as far apart as possible

34. Bent Shape Water H 2 O Two shared pairs and two unshared pairs The unshared pairs influence the shape

35. Tetrahedral Methane CH 4 Four shared pairs

36. Trigonal Planer BF 3 CH 2 O (Formaldehyde) 3 shared pairs Maximum distance apart

37. Trigonal Pyramidal 3 bonding pairs, 1 lone pair Ammonia NH 3

39. Molecular Shapes Affects a Substance’s Properties Shape affects Polarity

40. Polarity affects Properties