This document discusses the formation of covalent bonds. It defines covalent bonds as the sharing of electron pairs between nonmetal atoms. There are three types of covalent bonds: single, double, and triple bonds which are formed by the sharing of one, two, or three electron pairs respectively. Examples of bond formation in H2, O2, and N2 molecules are provided to illustrate single, double, and triple bonds. The key differences between ionic and covalent bonds are that ionic bonds involve electron transfer between metals and nonmetals while covalent bonds involve electron sharing between nonmetals.

1. CHAPTER 5
CHEMICAL BONDS

2. 5.3.1 Explain with examples the formation of
covalent bond
5.3.2 Compare ionic and covalent bonds
5.3 Covalent bond

3. 5.3.1 Explain with examples the formation of
covalent bond
 State the meaning of covalent bond
 Explain formation of covalent bond
 Illustrate the formation of covalent bond by drawing electron arrangement
 Illustrate formation of covalent bond
5.3 Covalent bond

4. Formation of covalent bond

5. Single Bond
o A single bond is formed when two atoms shared a pair of electrons.
o Example : The hydrogen molecule, H2
o A hydrogen atom has one valence electron.
o It needs one more electron to achieve duplet electron arrangement.
o Therefore two hydrogen atoms contribute one electron each for sharing.
o This shared-pair of electrons forms a single bond in the hydrogen molecule, H2.
1
Hydrogen atom, H
1
Hydrogen atom, H
+
A shared pair of electrons

6. Formation of Covalent Bond
● Covalent bonds are formed when non-metals atoms share their
electrons to achieve a stable duplet or octet electron
arrangement.
● There are three types of covalent bonds; single bond, double
bond and triple bond

7. Single Bond
Single bond
o A single covalent bond is formed when two atoms shared a pair of electrons.

8. Single Bond - Lewis Structure
● The formation of covalent bond can be visualized using the Lewis structure.
● Lewis structure only shows the valence electrons of the atoms involved.
● A pair of electrons shared is represented with a line between the two atoms.

9. Double Bond
Double bond
o A double bond is formed when two atoms share two pairs of electrons.

10. Triple Bond
Triple bond
o A triple bond is formed when two atoms share three pairs of electrons

11. EXPLAIN THE FORMATION OF CHLORINE MOLECULE
1. Chlorine atom with an electron arrangement 2.8.7 needs one electron to achieve a stable octet electron
arrangement.
2. Two chlorine atoms share one pair of electrons to achieve a stable octet electron arrangement, forming a
chlorine molecule.
3. Each chlorine atom achieves stable octet electron arrangement.
4. The number of electron pairs shared is one pair. Single covalent bond is formed.

12. EXPLAIN THE FORMATION OF OXYGEN MOLECULE
1. Oxygen atom with an electron arrangement 2.6 needs two electrons to achieve a stable octet
electron arrangement.
2. Two oxygen atoms share two pairs of electrons to achieve a stable octet electron
arrangement, forming an oxygen molecule.
3. Each oxygen atom achieves stable octet electron arrangement.
4. The number of electron pairs shared is two pairs. Double covalent bond is formed.
2.6
Oxygen atom, O
2.6
Oxygen atom, O
Oxygen molecule, O2

13. EXPLAIN THE FORMATION OF OXYGEN MOLECULE
1. Nitrogen atom with an electron arrangement 2.5 needs three electrons to achieve a stable
octet electron arrangement.
2. Two nitrogen atoms share three pairs of electrons to achieve a stable octet electron
arrangement, forming a nitrogen molecule.
3. Each nitrogen atom achieves stable octet electron arrangement.
4. The number of electron pairs shared is three pairs. Triple covalent bond is formed.

14. FORMATION OF COVALENT COMPOUND (Hydrogen chloride, HCl)
1. Hydrogen atom with an electron arrangement 1 needs one electron to achieve a stable duplet electron arrangement.
2. Chlorine atom with an electron arrangement 2.8.7 needs one electron to achieve stable octet electron arrangement.
3. One chlorine atom shares one pair of electrons with one hydrogen atom to form hydrogen chloride molecule with
formula HCl.
4. One chlorine atom contributes one electron and one hydrogen atom contributes one electron for sharing.
5. One chlorine atom forms one single covalent bond with one hydrogen atom.
6. Chlorine atom achieves stable octet electron arrangement and hydrogen atom achieve duplet electron arrangement.

15. 5.3.2 Compare ionic and covalent bonds
 Compare and contrast formation of ionic and covalent bonds
5.3 Covalent bond

16. COMPARISON BETWEEN IONIC BOND AND COVALENT BOND
SIMILARITIES
1. Formation of ionic bond and covalent bond involves valence electrons only.
2. Atoms form ionic bond and covalent bond to achieve a stable octet electron arrangement.
DIFFERENCES
Ionic Bond Covalent Bond
Ionic bond involves transfer of electrons.
Electrons
Covalent bond involves sharing of electrons.
Electrons are released by metal atoms
and received by non-metal atoms.
Pairs of electrons are shared by the same or
different non-metal atoms.
Between metal atoms and non-metal
atoms.
Type of element
involved
Between non-metal atoms and non-metal
atoms.
Metal atoms form a positively-charged
ion.
Non-metal atoms form a negatively-
charged ion.
Type of particle
formed
Forms a molecule
Lead(II) bromide, PbBr2 ;
sodium chloride, NaCl ;
copper(II) sulphate, CuSO4
Example of ionic
and covalent
compounds
Naphthalene, C8H10 ;
Acetamide, CH3CONH2 ;
Hexane, C6H14

17. COMPARISON BETWEEN IONIC BOND AND COVALENT BOND
DIFFERENCES
Ionic Bond Covalent Bond
Electron
arrangement in the
particles.
Ionic bond is the strong electrostatic force
of attraction between positively-charged
ion and negatively-charged ion.
Covalent bond is the shared pairs of electrons
between atoms in a molecule.
Strong covalent
bond between
atoms in the
molecules.
Strong electrostatic forces
between ions
1-
1-
2+