1. CHEMICAL BONDING IONIC BONDS COVALENT BONDS HYDROGEN BONDS METALLIC BONDS

3. IONIC BONDING When an atom of a nonmetal takes one or more electrons from an atom of a metal so both atoms end up with eight valence electrons

4. IONIC BONDING IS THE COMPOUND AN IONIC COMPOUND?METAL NONMETAL SUBSCRIPTS

5. IONIC BOND FORMATION Neutral atoms come near each other. Electron(s) are transferred from the Metal atom to the Non-metal atom. They stick together because of electrostatic forces, like magnets.

6. IONIC BONDING ION – any atom with more or less electrons that it is supposed to have* *Remember that the number of electrons is supposed to be equal to the number of Protons if the atom has a neutral charge

7. IONIC BONDING Metals will tend to lose electrons and become POSITIVE CATIONS Normal sodium atom loses one electron to become sodium ion

8. IONIC BONDING Nonmetals will tend to gain electrons and become NEGATIVE ANIONS Normal chlorine atom gains an electron to become a chloride ion

9. Properties of Ionic Compounds Crystalline structure. A regular repeating arrangement of ions in the solid. Ions are strongly bonded. Structure is rigid. High melting points- because of strong forces between ions.

11. COVALENT BONDING When an atom of one nonmetal shares one or more electrons with an atom of another nonmetal so both atoms end up with eight valence electrons

12. COVALENT BOND FORMATION When one nonmetal shares one or more electrons with an atom of another nonmetal so both atoms end up with eight valence electrons

13. COVALENT BONDING IS THE COMPOUND A COVALENT COMPOUND?NONMETAL NONMETAL YES since it is made of only nonmetal elements

14. Covalent bonding Fluorine has seven valence electrons F

15. Covalent bonding Fluorine has seven valence electrons A second atom also has seven FF

16. Covalent bonding l Fluorine has seven valence electrons l A second atom also has seven l By sharing electrons FF

17. Covalent bonding l Fluorine has seven valence electrons l A second atom also has seven l By sharing electrons FF

18. Covalent bonding l Fluorine has seven valence electrons l A second atom also has seven l By sharing electrons l Both end with full orbitals FF

19. Covalent bonding l Fluorine has seven valence electrons l A second atom also has seven l By sharing electrons l Both end with full orbitals FF 8 Valence electrons

20. Covalent bonding l Fluorine has seven valence electrons l A second atom also has seven l By sharing electrons l Both end with full orbitals FF 8 Valence electrons

21. Single Covalent Bond A sharing of two valence electrons. Only nonmetals and Hydrogen. Different from an ionic bond because they actually form molecules. Two specific atoms are joined. In an ionic solid you can’t tell which atom the electrons moved from or to.

22. Water H O Each hydrogen has 1 valence electron Each hydrogen wants 1 more The oxygen has 6 valence electrons The oxygen wants 2 more They share to make each other happy

23. Water Put the pieces together The first hydrogen is happy The oxygen still wants one more H O

24. Water The second hydrogen attaches Every atom has full energy levels H O H

25. Multiple Bonds Sometimes atoms share more than one pair of valence electrons. A double bond is when atoms share two pair (4) of electrons. A triple bond is when atoms share three pair (6) of electrons.

26. Carbon dioxide CO 2 - Carbon is central atom ( I have to tell you) Carbon has 4 valence electrons Wants 4 more Oxygen has 6 valence electrons Wants 2 more O C

27. Carbon dioxide Attaching 1 oxygen leaves the oxygen 1 short and the carbon 3 short O C

28. Carbon dioxide l Attaching the second oxygen leaves both oxygen 1 short and the carbon 2 short O C O

29. Carbon dioxide l The only solution is to share more O C O

30. Carbon dioxide l The only solution is to share more O C O

31. Carbon dioxide l The only solution is to share more O CO

32. Carbon dioxide l The only solution is to share more O CO

33. Carbon dioxide l The only solution is to share more O CO

34. Carbon dioxide l The only solution is to share more O CO

35. Carbon dioxide l The only solution is to share more l Requires two double bonds l Each atom gets to count all the atoms in the bond O CO

36. Carbon dioxide l The only solution is to share more l Requires two double bonds l Each atom gets to count all the atoms in the bond O CO 8 valence electrons

37. Carbon dioxide l The only solution is to share more l Requires two double bonds l Each atom gets to count all the atoms in the bond O CO 8 valence electrons

38. Carbon dioxide l The only solution is to share more l Requires two double bonds l Each atom gets to count all the atoms in the bond O CO 8 valence electrons

39. How to draw CO 2 You must show where the double bonds exist O=C=O

40. How to draw them Add up all the valence electrons. Count up the total number of electrons to make all atoms happy. Subtract. Divide by 2 Tells you how many bonds - draw them. Fill in the rest of the valence electrons to fill atoms up.

41. Examples NH 3 N - has 5 valence electrons wants 8 H - has 1 valence electrons wants 2 NH 3 has 5+3(1) = 8 NH 3 wants 8+3(2) = 14 (14-8)/2= 3 bonds 4 atoms with 3 bonds N H

42. NHH H Examples Draw in the bonds All 8 electrons are accounted for Everything is full

43. Examples HCN C is central atom N - has 5 valence electrons wants 8 C - has 4 valence electrons wants 8 H - has 1 valence electrons wants 2 HCN has 5+4+1 = 10 HCN wants 8+8+2 = 18 (18-10)/2= 4 bonds 3 atoms with 4 bonds -will require multiple bonds - not to H

44. HCN Put in single bonds Need 2 more bonds Must go between C and N NHC

45. HCN l Put in single bonds l Need 2 more bonds l Must go between C and N l Uses 8 electrons - 2 more to add NHC

46. HCN l Put in single bonds l Need 2 more bonds l Must go between C and N l Uses 8 electrons - 2 more to add l Must go on N to fill octet NHC

47. Another way of indicating bonds Often use a line to indicate a bond Called a structural formula Each line is 2 valence electrons HHO = HHO

48. Structural Examples H CN C O H H C has 8 electrons because each line is 2 electrons Ditto for N Ditto for C here Ditto for O

49. Coordinate Covalent Bond When one atom donates both electrons in a covalent bond. Carbon monoxide CO OC

50. Coordinate Covalent Bond l When one atom donates both electrons in a covalent bond. l Carbon monoxide l CO OC

51. Coordinate Covalent Bond l When one atom donates both electrons in a covalent bond. l Carbon monoxide l CO OC

52. Polar Bonds When the atoms in a bond are the same, the electrons are shared equally. This is a nonpolar covalent bond. When two different atoms are connected, the atoms may not be shared equally. This is a polar covalent bond. How do we measure how strong the atoms pull on electrons?

53. Electronegativity A measure of how strongly the atoms attract electrons in a bond. The bigger the electronegativity difference the more polar the bond. 0.0 - 0.3 Covalent nonpolar 0.3 - 1.67 Covalent polar >1.67 Ionic

54. How to show a bond is polar Isn’t a whole charge just a partial charge  means a partially positive  means a partially negative The Cl pulls harder on the electrons The electrons spend more time near the Cl H Cl  

55. Polar Molecules Molecules with ends

56. Polar Molecules Molecules with a positive and a negative end Requires two things to be true ¬ The molecule must contain polar bonds This can be determined from differences in electronegativity. ­ Symmetry can not cancel out the effects of the polar bonds. Must determine geometry first.

57. Is it polar? HF H 2 O NH 3 CCl 4 CO 2