This document discusses how to determine if an atom is a metal or non-metal based on its valence electrons, and describes the formation of ionic and covalent bonds. Ionic bonds form between metal and non-metal atoms through the transfer of electrons from the metal to the non-metal. Covalent bonds form between non-metal atoms through the sharing of electrons. Examples of ionic bond formation in sodium chloride and covalent bond formation in carbon dioxide are provided, along with electron diagrams to illustrate bonding.

1. CHAPTER 5 :
CHEMICAL BOND
FORM 4

2. HOW TO DETERMINE AN ATOM IS EITHER METAL
OR NON-METAL
• Take a look at valence electron of electron arrangement of an atom :
Example :
 2.8.1
• If the valence electrons are 1,2,3 , it is a metal atom.
• If the valence electrons are 4,5,6,7 , it is a non-metal atom.
• Green colour indicates valence electros

3. IONIC BOND
• Ionic bond is a bond formed between a metal atom and non-metal atom.
Example :
 Sodium chloride ( NaCl )
 This is because sodium is a metal atom which it electron arrangement is 2.8.1 while
 chlorine is a non-metal atom which it electron arrangement is 2.8.1
 Green colour indicates valence electrons
• Ionic bond involving release/donate electrons and receiving electrons.
• Metal atom will release/donate electrons.
• Non-metal atom will receive electrons.

4. Sodium,Na Chlorine,Cl
Electron arrangement 2.8.1 2.8.7
Electron needed to achieve
octet electron arrangement
1
(release/donate)
1
(receive)
Na
1
Cl
1
• Formed ionic compound NaCl.
• Electron diagram :

5. COVALENT BOND
• Covalent bond is a bond formed between non-metal and non-metal atom.
 Example :
• Carbon dioxide ( CO2 )
• This is because carbon and oxygen is non-metal atom.
• Electron arrangement of carbon is 2.4
• Electron arrangement of oxygen is 2.6
• Green colour indicates valence electron
• Covalent bond involving sharing of electrons.

6. Carbon,C Oxygen,O
Electron arrangement 2.4 2.6
Electron needed to achieve
octet electron arrangement
4 2
Simplest ratio 2 1
O
2
C
1
• Formed covalent compound CO2
• Electron diagram :

7. FORMATION OF IONIC BOND/COMPOUND
(ESSAY)
• Important content :
• Electron arrangement of atom
• Electron needed to achieve stable duplet electron arrangemet/ stable octet electron
arrangement for each atom
• Release electron to form ion
• Ion attracted by a strong electrostatic force of attraction
• Formed ionic compound with formula
• Electron diagram ( depends on question )

8. EXAMPLE
Formation of sodium chloride ( NaCl )
• Electron arrangement of sodium atom is 2.8.1 while electron arrangement of
chlorine atom is 2.8.1
• Sodium atom need to release 1 electron to achieve stable octet electron
arrangement and chlorine atom need to receive 1 electron to achieve stable octet
electron arrangement
• Sodium atom release I electron to form Na+ ion while chlorine atom receive 1
electron to form Cl- ion
• Na+ ion and Cl- ion are attracted by a strong electrostatic force of attraction
• Ionic compound with formula NaCl is formed

9. FORMATION OF COVALENT
BOND/COMPOUND (ESSAY)
Important content :
• Electron arrangement of atom
• Electron needed to achieve stable duplet electron arrangemet/ stable octet electron
arrangement for each atom
• Number of electrons shared/contributed by each atom
• Number of atom needed for sharing
• Formed covalent compound

10. EXAMPLE
Formation of tetrachloromethane ( CCl4 )
• The electron arrangement of carbon atom is 2.4 while electron arrangement of
chlorine atom is 2.8.7
• Carbon atom need 4 electrons to achieve stable octet electron arrangement while
chlorine atom need 1 electron to achieve stable octet electron arrangement.
• 1 carbon atom share/contribute 4 electrons for sharing and 1 chlorine atom
share/contribute 1 electron for sharing.
• 1 carbon atom share/contribute 4 electron for sharing and 4 chlorine atom
share/contribute 4 electrons for sharing.
• Covalent compound CCl4 is formed