1. BONDING

2. Covalent Bonds

3. LET’S FIRST REVIEW IONIC BONDING

4. In an IONIC bond, electrons are lost or gained, resulting in the formation of IONS in ionic compounds. F K

5. F K

6. F K

7. F K

8. F K

9. F K

10. F K

11. F K + _

12. F K The compound potassium fluoride consists of potassium (K + ) ions and fluoride (F - ) ions + _

13. F K + _ The ionic bond is the attraction between the positive K + ion and the negative F - ion

14. So What Are Covalent bonds?

15. In covalent bonding, atoms still want to achieve a noble gas configuration (the octet rule).

16. In covalent bonding, atoms still want to achieve a noble gas configuration (the octet rule). But rather than losing or gaining electrons, atoms now share an electron pair.

17. In covalent bonding, atoms still want to achieve a noble gas configuration(the octet rule). But rather than losing or gaining electrons, atoms now share an electron pair. The shared electron pair is called a bonding pair

18. Cl 2 Chlorine Forms A Covalent Bond With itself

19. Cl Cl How Will Two Chlorine Atoms react?

20. Cl Cl Each chlorine atom wants to gain one electron to achieve an octet

21. Cl Cl Neither atom will give up an electron –chlorine is highly electronegative. What’s the solution – what can theydo to achieve an octet?

22. Cl Cl

23. Cl Cl

24. Cl Cl

25. Cl Cl

26. Cl Cl octet

27. Cl Cl circle the electrons for each atom that completes their octets octet

28. Cl Cl circle the electrons for each atom that completes their octets The octet is achieved by each atom sharing the electron pair in the middle

29. Cl Cl circle the electrons for each atom that completes their octets The octet is achieved by each atom sharing the electron pair in the middle

30. Cl Cl circle the electrons for each atom that completes their octets This is the bonding pair

31. Cl Cl circle the electrons for each atom that completes their octets It is a single bonding pair

32. Cl Cl circle the electrons for each atom that completes their octets It is called a SINGLE BOND

33. Cl Cl circle the electrons for each atom that completes their octets Single bonds are abbreviated with a dash

34. Cl Cl circle the electrons for each atom that completes their octets This is the chlorine molecule, Cl 2

35. O 2 Oxygen is also one of the diatomic molecules

36. How will two oxygen atoms bond? O O

37. Each atom has two unpaired electrons O O

38. O O

39. O O

40. O O

41. O O

42. O O

43. O O

44. Oxygen atoms are highly electronegative. So both atoms want to gain two electrons. O O

45. Oxygen atoms are highly electronegative. So both atoms want to gain two electrons. O O

46. O O

47. O O

48. O O

49. O O

50. O O Both electron pairs are shared.

51. 6 valence electrons plus 2 shared electrons = full octet O O

52. 6 valence electrons plus 2 shared electrons = full octet O O

53. two bonding pairs, O O making a double bond

54. For convenience, the double bond can be shown as two dashes. O O = O O

55. This is the oxygen molecule, O 2 O O = this is so cool!!

56. Covalent bonding allows for an amazingly large variety of compounds such as

57. small compounds like water and carbon dioxide,

58. and ethanol (alcohol),

59. to larger compounds such as aspirin, (21 atoms)

60. and the sex hormones estradiol (estrogen) and testosterone, (49 atoms) (44 atoms)

61. to all of the 40,000 proteins you have in your body, including

62. insulin, with 779 atoms,

63. and hemoglobin, with about 9500 atoms!

64. There are an estimated 10 40 possible compounds containing up to 50 atoms The known chemical world, including natural and synthetic compounds, is far far far below 1% of that.

65. As of 2007, there are about 31,000,000 known compounds; About 12.5 million of those are commercially available. Thousands of new compounds are discovered or synthesized every week !