2. The Periodic Table

3. Atomic Number (number of protons) Symbol Atomic Mass Period

4. The Periodic Table Groups are based on number of valence electrons (electrons in the outer shell or energy level) of each element

5. The Periodic Table Dot Diagrams

6. The Periodic Table

7. Patterns of Valence Electrons Lithium Atomic Number (number of protons) Period Symbol Atomic Mass

8. Patterns of Valence Electrons Number of Energy Levels: 2 First Energy Level: 2 Second Energy Level: 1 Lithium

9. Patterns of Valence Electrons Beryllium Atomic Number (number of protons) Symbol Atomic Mass Period

10. Patterns of Valence Electrons Number of Energy Levels: 2 First Energy Level: 2 Second Energy Level: 2 Beryllium

11. Patterns of Valence Electrons Boron Atomic Number (number of protons) Symbol Atomic Mass Period

12. Patterns of Valence Electrons Boron Number of Energy Levels: 2 First Energy Level: 2 Second Energy Level: 3

13. Patterns of Valence Electrons Sodium Atomic Number (number of protons) Symbol Atomic Mass Period

14. Patterns of Valence Electrons Sodium Number of Energy Levels: 3 1 st Energy Level: 2 2 nd Energy Level: 8 3 rd Energy Level: 1

15. Patterns of Valence Electrons Number of Energy Levels: 4 1 st Energy Level: 2 2 nd Energy Level: 8 3 rd Energy Level: 8 4 th Energy Level: 1

16. Patterns of Valence Electrons Number of Energy Levels: 5 1 st Energy Level: 2 2 nd Energy Level: 8 3 rd Energy Level: 18 4 th Energy Level: 8 5 th Energy Level: 1

17. Patterns of Valence Electrons Number of Energy Levels: 6 1 st Energy Level: 2 2 nd Energy Level: 8 3 rd Energy Level: 18 4 th Energy Level: 18 5 th Energy Level: 8 6 th Energy Level: 1

18. Patterns of Valence Electrons Number of Energy Levels: 7 1 st Energy Level: 2 2 nd Energy Level: 8 3 rd Energy Level: 18 4 th Energy Level: 32 5 th Energy Level: 18 6 th Energy Level: 8 7 th Energy Level: 1

19. The Periodic Table A row of elements across the periodic table is called a Period The atomic number increases one at a time across a period of elements

20. The Periodic Table Period 2 starts with Lithium Period 2 and continues across to Neon

21. The Periodic Table

22. Elements with the same number of valence electrons have similar properties

23. The Periodic Table For example, lithium, sodium,

24. The Periodic Table For example, lithium, sodium, and the rest of the elements in Group 1 are all alkali metals which are very reactive Alkali Metals

25. The Periodic Table GROUP 1

26. The Periodic Table GROUP 1 Alkali Metals 1 Valence electron in outer shell. Very REACTIVE

27. The Periodic Table GROUP 18 NOBEL GASES

28. The Periodic Table GROUP 18 NOBEL GASES 8 Valence Electrons in outer shell. Very Stable

29. The Periodic Table GROUP 17 HALOGENS

30. The Periodic Table GROUP 17 HALOGENS 7 Valence Electrons in outer shell. Very Reactive

31. The Periodic Table Other metals Groups 2 through 12

32. The Periodic Table Most have 1, 2, or 3 Valence electrons

33. The Periodic Table They react by losing electrons

34. The Periodic Table Other Nonmetals (Green)

35. The Periodic Table React by gaining electrons

36. The Periodic Table Metalloids (Yellow)

37. The Periodic Table Behave as metals or nonmetals

38. The Periodic Table Can lose or share electrons

39. The Periodic Table Hydrogen

40. The Periodic Table Considered a nonmetal

41. The Periodic Table Located above Group 1

42. The Periodic Table One valence electron

43. The Periodic Table Very REACTIVE

44. The Periodic Table QUESTIONS?

45. Chemical Formulas and Names What is a chemical formula? Compounds can be represented by chemical formulas

46. Chemical Formulas and Names A chemical formula is a combination of symbols that shows the ratio of elements in a compound.

47. Chemical Formulas and Names Formulas of Ionic Compounds MgCl 2 The formula for magnesium chloride.

48. Chemical Formulas and Names Formulas of Ionic Compounds MgCl 2 (Magnesium Chloride) One Magnesium ion Two Chloride ions

49. Chemical Formulas and Names Formulas of Ionic Compounds MgCl 2 Mg Cl 2+ 1-

50. Chemical Formulas and Names Formulas of Ionic Compounds NaCl One Sodium ion One Chloride ion

51. Chemical Formulas and Names Formulas of Ionic Compounds NaCl Na Cl 1+ 1-

52. Chemical Formulas and Names Naming Ionic Compounds The name of the positive ion comes first… Followed by the name of the negative ion

53. Chemical Formulas and Names Naming Ionic Compounds If the negative ion is a single element the end of its name changes to -ide MgO = Magnesium Oxide NaCl = Sodium Chloride

54. Chemical Formulas and Names Naming Ionic Compounds If the negative ion is a polyatomic element the end of its name changes to –ate or -ite NH 4 NO 3 = Ammonium Nitrate

55. Ionic Compounds They have opposite charges and opposite charges attract Why do sodium and chloride ions bond together?

56. Ionic Compounds General Properties or Characteristics of Ionic Compounds High melting points Conduct electricity when dissolved or melted Hard, brittle crystals Energy is required to break ionic bonds

57. Ionic Compounds What are Ionic compounds? Ionic compounds are compounds that consist of positive and negative compounds

58. Molecular Compounds What are Molecular compounds? Molecular compounds are compounds that contain molecules bonded with COVALENT bonds

59. Covalent Bonds What is a covalent bond? The chemical bond formed when two atoms share electrons

60. How Covalent Bonds Form

61. Covalent bonds usually form between atoms of nonmetals Ionic Compounds vs Molecular Compounds Ionic bonds usually form when a metal combines with a nonmetal

62. In Ionic bonding, atoms give up or gain an electron Ionic Compounds vs Molecular Compounds In covalent bonding, atoms share electrons

63. NaCl Na Cl 1+ 1- Ionic Compounds vs Molecular Compounds Ionic Bonding

64. Ionic Compounds vs Molecular Compounds Covalent Bonding

65. Covalent Bonds What is a covalent bond? The chemical bond that forms when two atoms share electrons

66. Covalent Bonds H H Hydrogen Atom Oxygen Atom Water Molecule with two covalent bonds

67. Covalent Bonds How many covalent bonds can an atom form? Oxygen has 6 valence electrons so it can form 2 covalent bonds

68. Covalent Bonds How many covalent bonds can an atom form? The exception is Hydrogen which only needs two electrons to be complete H

69. Covalent Bonds How many covalent bonds can an atom form? Each Hydrogen atom can form one bond because it only needs 2 electrons to be stable H

70. Covalent Bonds H H H Hydrogen Atoms Nitrogen Atom

71. Covalent Bonds H H H Ammonia molecule… Three covalent bonds

72. Covalent Bonds Double and Triple Bonds Oxygen Atom

73. Covalent Bonds Double and Triple Bonds Oxygen Molecule

74. Covalent Bonds Double and Triple Bonds Go to page 32 of your textbook