1. CHEMICAL BONDS IKATAN KIMIA
CHAPTER 2
CHEMICAL BONDS
IKATAN KIMIA

2. Teaching Learning Objectives
The student can explain tendency of element to become stable.
The student can make figure Lewis structure of valence electron noble gas group and the other.
The student can explain forming of ionic bond.
The student can explain properties of ionic compound.

3. Stability of Element Valence Electrons Atom Electron Configuration
2He
10Ne
18Ar
36Kr
56Xe
86Rn 2 2
2 8 8
2 8 8 8 8 8 8

4. How do the electron configuration of atoms beside noble gases to achieve the stability ?
Example :
11Na
Na+
+ e
2 8 1
2 8
12Mg
Mg+2
+ 2e
2 8 2
2 8
Cl-
17Cl
+ e
2 8 8
2 8 7 8O
+ 2e
O-2
2 6
2 8

5. The tendency of Element to achieve the stability of noble gases.
Group
Valence Electron
Electron Configuration
Tendency of Achieve
Stability IA
IIA
IIIA
IVA VA
VIA
VIIA 1 2 3 4 5 6 7
3Li : 2 1
4Be : 2 2
5B : 2 3
6C : 2 4
7N : 2 5
8O : 2 6
9F : 2 7
Give away 1 electron
Give away 2 electron
Give away 3 electron
Gain 4 electron
Gain 3 electron
Gain 2 electron
Gain 1 electron

6. Ionic Bond How is the formation of ionic bonds ?
Ionic bond arise form;
Metal elements and non metal elements
Group IA/IIA and group VIIA
Group IA/IIA tendency give away electron for formation of positif ion and group VIIA tendency gain electron for formation of negative ion.

7. Example : Na+ + e Na Na+ + e + e Cl- + e Cl- + Cl2 2Na+ + 2Cl- 2NaCl 2
2 8 1
2 8 Cl
+ e 2 2
Cl-
17Cl
+ e 2
Cl-
2 8 7
+ Cl2
2 8 8
2Na
2Na+ + 2Cl-
2NaCl

8. O O2 2O O2 2O + O2 +2O Mg 2e Mg + Mg + 2e 2 8 2 2 8 +2e +4e 2 6 2 82+
12Mg 2+ Mg 2e Mg + Mg + 2e x2
2 8 2
2 8 2- 2- 8O
+2e O O2 2O
+4e x1
2 6
2 8 2+
2Mg
2Mg + 4e O2
+4e 2O 2- 2+ 2-
2Mg
+ O2
2Mg
+2O 2
MgO

9. What are the properties of ionic compounds ?
Ionic coumpounds have some physical properties.
Among orthers are :
Generally solids at room temperature,
Have a high boiling and melting point,
Conduct electricity when molten or aqueous solution,
Hard but brittle.

10. Kerjakan pembentukan ikatan ion dari atom-atom berikut ini:
K dan S
Ca dan S
Na dan S
Al dan S
Al dan O
Al dan Cl
Mg dan O