1. I’m Bond,
Chemical Bond

2. Atom – the smallest unit of matter “indivisible”
Helium
atom

3. electron shells Atomic number = number of Electrons
Electrons vary in the amount of energy they possess, and they occur at certain energy levels or electron shells.

4. Electrons are placed in shells according to rules:
The 1st shell can hold up to two electrons, and each shell thereafter can hold up to 8 electrons.

5. Octet Rule = atoms tend to gain, lose or share electrons so as to have 8 electrons
C would like to
N would like to
O would like to
Gain 4 electrons
Gain 3 electrons
Gain 2 electrons

6. Why are electrons important?
Elements have different electron configurations
different electron configurations mean different ways of bonding – and different products from their reactions

7. Noble gases

8. Electron Dot Structures
Symbols of atoms with dots to represent the outermost shell electrons /8
H He:
          
Li Be  B   C   N   O  : F  :Ne :
       
          
Na Mg  Al  Si  P S :Cl  :Ar :
       

9. Chemical bonds: an attempt to fill electron shells
Ionic bonds –
Covalent bonds –
Metallic bonds

10. Learning Check A. X would be the electron dot formula for
A. X would be the electron dot formula for
1) Na 2) K 3) Al
 
B  X  would be the electron dot formula
1) B 2) N 3) P

11. IONIC BOND bond formed between two ions by the transfer of electrons

12. Formation of Ions from Metals
Ionic compounds result when metals react with nonmetals
Metals lose electrons to match the number of outermost shell electrons of their nearest noble gas
Positive ions form when the number of electrons are less than the number of protons
Group 1 metals  ion 1+
Group 2 metals  ion 2+
Group 13 metals  ion 3+

13. Formation of Sodium Ion
Sodium atom Sodium ion
Na  – e  Na +
( = Ne)
11 p p+
11 e e-

14. Formation of Magnesium Ion
Magnesium atom Magnesium ion 
Mg  – 2e  Mg2+
(=Ne)
12 p p+
12 e e-

15. Some Typical Ions with Positive Charges (Cations)
Group 1 Group 2 Group 13
H+ Mg2+ Al3+
Li+ Ca2+
Na+ K+

16. Learning Check A. Number of outermost shell electrons in aluminium
1) 1 e ) 2 e- 3) 3 e-
B. Change in electrons for octet
1) lose 3e ) gain 3 e ) gain 5 e-
C. Ionic charge of aluminium
1) ) ) 3+

17. Solution A. Number of outermost shell electrons in aluminium 3) 3 e-
B. Change in electrons for octet
1) lose 3e-
C. Ionic charge of aluminium
3) 3+

18. Learning Check Give the ionic charge for each of the following:
A. 12 p+ and 10 e-
1) 0 2) 2+ 3) 2-
B. 50p+ and 46 e-
1) 2+ 2) 4+ 3) 4-
C. 15 p+ and 18e-
2) ) 3- 3) 5-

19. Ions from Nonmetal Ions
In ionic compounds, nonmetals gain electrons from metals
Nonmetal add electrons to achieve the octet arrangement
Nonmetal ionic charge:
3-, 2-, or 1-

20. Fluoride Ion     1 - : F  + e : F :     2-7 2-8 (= Ne)
unpaired electron octet
   
: F  e : F :
   
(= Ne)
9 p p+
9 e e-
ionic charge

21. Ionic Bond Between atoms of metals and nonmetals
Bond formed by transfer of electrons
Produce charged ions. Conductors and have high melting point.
Examples; NaCl, CaCl2, K2O

23. 1). Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged particles or ions.

25. COVALENT BOND bond formed by the sharing of electrons

26. Covalent Bond Between nonmetallic elements
Formed by sharing electron pairs
Stable non-charged particles, they are not conductors at any state
Examples; O2, CO2, C2H6, H2O, SiC

27. Covalent Bonds

28. Bonds in all the polyatomic ions and diatomics are all covalent bonds

29. when electrons are shared equally
COVALENT BOND in elements
when electrons are shared equally
H2 or Cl2

30. 2. Covalent bonds- Two atoms share one or more pairs of outer-shell electrons.
Oxygen Atom
Oxygen Atom
Oxygen Molecule (O2)

31. when electrons are shared but shared unequally
COVALENT BONDS in compounds
when electrons are shared but shared unequally
H2O

32. - water is a polar molecule because oxygen is more electronegative than hydrogen, and therefore electrons are pulled closer to oxygen.

33. METALLIC BOND bond found in metals; holds metal atoms together very strongly

34. Metallic Bond Formed between atoms of metallic elements
Electron cloud around atoms
Good conductors at all states, lustrous, very high melting points
Examples; Na, Fe, Al, Au, Co

35. Ionic Bond, A Sea of Electrons

36. Metals Form Alloys Metals do not combine with metals. They form
Alloys which is a solution of a metal in a metal.
Examples are steel, brass, bronze and pewter.

38. Compounds and Their Bonds
Ionic Compounds
Naming Ionic Formulas

39. Ionic Compounds Attraction between + ions and - ions
Electrons go from metals to nonmetals
electron transfer
metal nonmetal ion+ ion–
Electrons lost = Electrons gain

40. Formulas of Ionic Compounds
Formulas of ionic compounds are determined from the charges on the ions
atoms ions
    –
Na  +  F :  Na : F :  NaF
   
sodium fluorine sodium fluoride formula
Charge balance: = 0

41. Writing a Formula
Write the formula for the ionic compound that will form between Ba2+ and Cl.
Solution:
1. Balance charge with + and – ions
2. Write the positive ion of metal first, and the
negative ion Ba Cl Cl
3. Write the number of ions needed as
subscripts BaCl2

42. Learning Check
Write the correct formula for the compounds containing the following ions:
A. Na+, S2-
1) NaS 2) Na2S 3) NaS2
B. Al3+, Cl-
1) AlCl3 2) AlCl 3) Al3Cl
C. Mg2+, N3-
1) MgN 2) Mg2N3 3) Mg3N2

43. Solution A. Na+, S2- 2) Na2S B. Al3+, Cl- 1) AlCl3 C. Mg2+, N3-

44. Naming Binary Ionic Compounds
Contain 2 different elements
Name the metal first, then the nonmetal as -ide.
Use name of a metal with a fixed charge
Groups 1A, 2A, 3A
and Ag, Zn, and Cd
Examples:
NaCl sodium chloride
ZnI2 zinc iodide
Al2O3 aluminum oxide

45. Learning Check Complete the names of the following binary compounds:
Na3N sodium ________________
KBr potassium ________________
Al2O3 aluminum ________________
MgS _________________________

46. Solution Complete the names of the following binary compounds:
Na3N sodium nitride
KBr potassium bromide
Al2O3 aluminum oxide
MgS magnesium sulfide

47. Learning Check A. The formula for the ionic compound of Na+ and O2- is
1) NaO 2) Na2O 3) NaO2
B. The formula of a compound of aluminum and chlorine is
1) Al3Cl 2) AlCl2 3) AlCl3
C. The formula of Fe3+ and O2- is
1) Fe3O2 2) FeO3 3) Fe2O3

48. Solution A. The formula for the ionic compound of Na+ and O2- is
2) Na2O
B. The formula of a compound of aluminum and chlorine is
3) AlCl3
C. The formula of Fe3+ and O2- is
3) Fe2O3

49. Learning Check 3) cobalt trioxide Name the following compounds: A. CaO
1) calcium oxide 2) calcium(I) oxide
3) calcium (II) oxide
B. SnCl4
1) tin tetrachloride 2) tin(II) chloride
3) tin(IV) chloride
C. Co2O3
1) cobalt oxide ) cobalt (III) oxide
3) cobalt trioxide

50. Solution Name the following compounds: A. CaO 1) calcium oxide
B SnCl4 3) tin(IV) chloride
C. Co2O3 2) cobalt (III) oxide

51. Q1. Name a metal in group 1 that is in the same period as Magnesium.
Q2. Name a metal in group 2 that in the same period as Lithium.
Q3. Name a non-metal in the same group as Nitrogen.
Q4. Name a noble gas in the same period as Oxygen.
Q5. Name a gas in group 7 that is in the same period as Aluminium.

52. Objective:
1. Learn the scientific method for naming compounds.
2. There are three rules for naming compounds: the “ide” rule, the “ate” rule and the “same” rule.

53. Rule 1: When two elements combine the ending is usually ” ……………ide”
Rule 1: When two elements combine the ending is usually ” ……………ide”. metal goes first
Sodium Chloride
Magnesium Oxide
Iron Sulphide Cl Na Mg O Fe S

54. Rule 2: When three or more different elements combine and one of them is Oxygen, the ending will be “………ate”.
metal goes first
Copper Sulphate
Calcium Carbonate O O Cu S O O O O C Ca O

55. Rule 3: When two identical elements combine, the name does not change.
H2 = Hydrogen
F2 = Fluorine
N2 = Nitrogen
Cl2 = Chlorine
O2 = Oxygen H F N Cl O

56. Name the following compound
Na2O

57. Name the following compound
CuSO4

58. Name the following compound
MgSO4

59. Name the following compound
ZnO

60. Name the following compound
MgCl2

61. Name the following molecule

62. Name the following compoundKI

63. Name the following compound
AgNO3