1. Ionic bond

3. One electron lost

5. One electron gained

7. The formation of sodium chloride (NaCl) from sodium (Na) and chlorine (Cl)

8. Note that we don’t have to draw the inner shell electrons anymore!
These diagrams are called Lewis structures, Lewis dot diagrams, or electron dot diagrams

9. Name of compound: Sodium chloride
Chemical formula: NaCl

10. Ions: cation and anion Ions – charged particles
Cation: Metal atoms lose electrons to form positively charged ions
Anion: Non-metal atoms gain electrons to form negatively charged ions
Cations (+) and anions (-) attract each other by electrostatic attraction to form ionic compound

11. Cations (+) and anions (-) attract each other by electrostatic attraction in all directions

12. The pattern grows until a giant lattice structure of ions is formed
Pure ionic compounds exist as solid crystals

16. Two electrons lost

18. Two electrons gained

19. Name of compound: Magnesium oxiide
Chemical formula: MgO

20. Sodium chloride
NaCl
Magnesium oxide
MgO

21. Try magnesium + fluorine
Determine how many electron(s) magnesium need to lose, therefore the charge of the magnesium ion
Determine how many electron(s) fluorine need to gain, therefore the charge of the fluoride ion
Determine how many of each ions are needed to balance out the positive and negative charges

23. Two electrons lost

25. One electron gained

27. To obtain full outer shells, a magnesium atom must lose 2 electrons, and a fluorine atom must gain 1 electron.

28. Each magnesium atom loses two electrons to form magnesium ion Mg2+ Each fluorine atom gains one electron to form fluoride ion F-

29. Each magnesium atom reacts with two fluorine atoms to form magnesium fluoride with the chemical formular MgF2.

30. Try sodium + oxygen
Determine how many electron(s) sodium need to lose, therefore the charge of the sodium ion
Determine how many electron(s) oxygen need to gain, therefore the charge of the oxide ion
Determine how many of each ions are needed to balance out the positive and negative charges

31. 2 Na+ + O2-  Na2O
Sodium oxide

32. Naming simple ionic compounds
Write the name of the metal.
Write the name of the nonmetal with the ending changed to –ide.
Example:
Chlorine = chloride Oxygen = oxide
Fluorine = fluoride Sulfur = sulfide
Iodine = iodide Nitrogen = nitride
Bromine = bromide Phosphorous = phosphide

34. Polyatomic ions Ions made of more than one atom bonded together
They behave as one ion with one overall charge

35. Example: Calcium carbonate
Calcium ion – Ca2+
Carbonate ion – CO32-

36. Calcium carbonate – CaCO3

37. Homework Memorize the first 20 elements (This week)
Atomic number
Name
Atomic symbol
Memorize the common polyatomic ions (Next week)
Formula
Charge

38. Magnesium + nitrogen Magnesium has 2 valence electrons
Magnesium needs to lose 2 electrons to meet the octet rule
Forms Mg2+ cation
Mg  Mg2+ + 2e-
Nitrogen has 5 valence electrons
Nitrogen needs to gain 3 more electrons to meet the octet rule
Forms N3- anion (nitride ion)
N + 3e-  N3-
Lowest common multiple of 2 and 3 = 6
3 Mg  3 Mg2+ + 6e-
2 N + 6e-  2 N3-
Magnesium nitride Mg3N2