1. Bohr Diagrams for Ions

2. Showing Protons, Neutrons and Electron Arrangements

3. Ions Ions are formed when neutral atoms lose or gain electrons

4. Ions are formed when neutral atoms lose or gain electrons and end up with a positive or negative charge.

5. A few points to remember:

6. A proton is + and an electron is –

7. A few points to remember: A proton is + and an electron is – In a neutral atom the # of protons = # of electrons

8. A few points to remember: A proton is + and an electron is – In a neutral atom the # of protons = # of electrons When atoms form ions, they do so only by losing or gaining electrons.

9. A few points to remember: A proton is + and an electron is – In a neutral atom the # of protons = # of electrons When atoms form ions, they do so only by losing or gaining electrons. They never change the number of protons.

10. A few points to remember: A proton is + and an electron is – In a neutral atom the # of protons = # of electrons When atoms form ions, they do so only by losing or gaining electrons. They never change the number of protons. When a neutral atom loses one or more electrons, it gains a + charge, and it called a cation.

11. A few points to remember: A proton is + and an electron is – In a neutral atom the # of protons = # of electrons When atoms form ions, they do so only by losing or gaining electrons. They never change the number of protons. When a neutral atom loses one or more electrons, it gains a + charge, and it called a cation. When a neutral atom gains one or more electrons, it gains a – charge, and it is called an anion.

12. When atoms interact with each other, they use only the electrons in the outermost occupied shell.

13. valence shell The outermost occupied shell is called the valence shell.

14. When atoms interact with each other, they use only the electrons in the outermost occupied shell. The outermost occupied shell is called the valence shell. valence electrons Electrons in the outermost occupied shell are called valence electrons.

15. For example, here is the Bohr model for nitrogen, element number 7. 7 p 7 n

16. For example, here is the Bohr model for nitrogen, element number 7. 7 p 7 n The Valence Shell

17. For example, here is the Bohr model for nitrogen, element number 7. 7 p 7 n Valence Electron

18. Here is another example, the Bohr model for magnesium, element number 12. 12 p 12 n

19. Here is another example, the Bohr model for magnesium, element number 12. 12 p 12 n The Valence Shell

20. Here is another example, the Bohr model for magnesium, element number 12. 12 p 12 n Valence electron

21. Here are some points to know about cation and anion formation:

22. Elements with 1—3 valence electrons tend to lose these electrons and form positive ions, or cations.

23. Here are some points to know about cation and anion formation: Elements with 1—3 valence electrons tend to lose these electrons and form positive ions, or cations. Elements with 5—7 valence electrons tend to gain electrons in order to fill up their valence shells.

24. Here are some points to know about cation and anion formation: Elements with 1—3 valence electrons tend to lose these electrons and form positive ions, or cations. Elements with 5—7 valence electrons tend to gain electrons in order to fill up their valence shells. When they gain electrons they form negative ions, or anions.

25. Let’s do a couple of examples:

26. 3 p 4 n Lithium atom

27. 3 p 4 n Lithium atom Valence electron

28. 3 p 4 n LithiumLithium atom

29. 3 p 4 n LithiumLithium atom

30. 3 p 4 n LithiumLithium atom

31. 3 p 4 n Lithium ion

32. 3 p 4 n Lithium Lithium ion

33. 3 p 4 n Lithium Lithium ion

34. 3 p 4 n Lithium ion

35. 3 p 4 n Lithium ion

36. 3 p 4 n Lithium ion + 3 charge

37. 3 p 4 n Lithium ion + 3 charge –2 charge

38. 3 p 4 n Lithium ion + 3 charge –2 charge Net charge

39. 3 p 4 n Lithium ion + 3 charge –2 charge Net charge = 3

40. 3 p 4 n Lithium ion + 3 charge –2 charge Net charge = 3–2

41. 3 p 4 n Lithium ion + 3 charge –2 charge Net charge = 3–2 = +1

42. 3 p 4 n Lithium ion +1 Net charge = 3–2 = +1

43. 3 p 4 n +1 Bohr Model for a Li + ion

44. 3 p 4 n +1 Bohr Model for a Li + ion 2 p 4 n Bohr Model for a Neutral He Atom Same electron arrangement as

45. 3 p 4 n +1 Bohr Model for a Li + ion 2 p 4 n Bohr Model for a Neutral He Atom Same electron arrangement as

46. 3 p 4 n +1 Bohr Model for a Li + ion 2 p 4 n Bohr Model for a Neutral He Atom Same electron arrangement as

47. 3 p 4 n +1 Bohr Model for a Li + ion 2 p 4 n Bohr Model for a Neutral He Atom Same electron arrangement as

48. 3 p 4 n +1 Bohr Model for a Li + ion 2 p 4 n Bohr Model for a Neutral He Atom Same electron arrangement as

49. Bohr Model for a Sulphur Atom 16 p 16 n

50. Bohr Model for a Sulphur Atom 16 p 16 n Valence Shell

51. Bohr Model for a Sulphur Atom 16 p 16 n

52. Bohr Model for a Sulphur Atom 16 p 16 n

53. 16 p 16 n

54. 16 p 16 n

55. 16 p 16 n

56. 16 p 16 n

57. 16 p 16 n

58. 16 p 16 n

59. 16 p 16 n

60. 16 p 16 n

61. 16 p 16 n

62. 16 p 16 n 18 e –

63. 16 p 16 n 18 e – 16 p +

64. 16 p 16 n 18 e – 16 p +

65. 16 p 16 n 18 e – 16 p + –2

66. 16 p 16 n 18 e – 16 p + –2 Net charge

67. 16 p 16 n –2 Net charge

68. 16 p 16 n –2 Net charge

69. 16 p 16 n 2–

70. 16 p 16 n 2– Bohr Model for an S 2– or sulphide ion

71. 16 p 16 n 2– Bohr Model for an S 2– or sulphide ion

72. 16 p 16 n 2– Bohr Model for an S 2– or sulphide ion 18 p 22 n Bohr Model for a neutral Argon Atom

73. 16 p 16 n 2– Bohr Model for an S 2– or sulphide ion 18 p 22 n Bohr Model for a neutral Argon Atom

74. 16 p 16 n 2– Bohr Model for an S 2– or sulphide ion 18 p 22 n Bohr Model for a neutral Argon Atom STABLE