SPM Chemistry (KSSM) Paper 1

01 Introduction to Chemistry
1.1 Chemistry and Its Importance
1 Lesson
1.1.1 Chemistry and Its Importance
1.2 Scientific Investigation
1 Lesson
1.2.1 Scientific Investigation
02 The Structure of Atoms
2.1 The Basic Concept of Matter
2 Lessons
2.1.1 The Particle Theory of Matter
2.1.2 The Three States of Matter
2.2 The History of Development of the Atomic Model
1 Lesson
2.2.1 The History of Development of the Atomic Model
2.3 The Structure of Atom
2 Lessons
2.3.1 The Structure of Atom
2.3.2 Electrons Arrangement in Atom
2.4 Isotopes and Their Uses
1 Lesson
2.4.1 Isotopes and Their Uses
3.1 Relative Atomic Mass and Relative Molecular Mass
1 Lesson
3.1.1 Relative Atomic Mass and Relative Molecular Mass
03 Concept of Mole, Formulae and Equations
3.2 Concept of Mole
3 Lessons
3.2.1 Concept of Mole
3.2.2 Number of Mole and Mass
3.2.3 Number of Mole and Volume of Gases
3.3 Chemical Formulae
2 Lessons
3.3.1 Chemical Formulae
3.3.2 Formula of Ionic Compounds and Molecule
3.4 Chemical Equations
1 Lesson
3.4.1 Chemical Equations
4.1 The Development of Periodic Table
1 Lesson
4.1.1 Development of Periodic Table
4.2 Arrangement of Element in Periodic Table
1 Lesson
4.2.1 Arrangement of Electrons in Periodic Table
04 Periodic Table of Elements
4.3 Group 18 Elements
1 Lesson
4.3.1 Group 18 Elements
4.4 Group 1 Elements
2 Lessons
4.4.1 Group 1 Elements
4.4.2 Chemical Properties of Group 1 Elements
4.5 Group 17 Elements
2 Lessons
4.5.1 Group 17 Elements
4.5.2 Chemical Properties of Group 17 Elements
4.6 Elements in Period 3
1 Lesson
4.6.1 Elements in Period 3
4.7 Transition Elements
1 Lesson
4.7.1 The Transition Elements
5.1 Formation of Compounds
1 Lesson
5.1.1 Formation of Compounds
5.2 Ionic Bonds
2 Lessons
5.2.1 Formation of Ion
5.2.2 Ionic Bonding
5.3 Covalent Bonds
1 Lesson
5.3.1 Covalent Bonding
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5.3.1 Covalent Bonding

SPM Chemistry (KSSM) Paper 1 5.3 Covalent Bonds 5.3.1 Covalent Bonding

Covalent Bonding

  1. Covalent bonds are formed by atoms sharing electrons to form molecules. This type of bond usually formed between two non-metallic elements.
  2. In the formation of covalent bonds, atoms of non-metals will combine with each other to donate one, two or three electrons for sharing.
  3. The compound formed through the formation of covalent bonds is called the covalent compounds.

Examples of Covalent Compound

Covalent CompoundFormulaCovalent CompoundFormula
ChlorineCl2PhosphorusP4
HydrogenH2Sulfur dioxideSO2
OxygenO2Carbon dioxideCO2
NitrogenN2Tetrachloro-methaneCCl4

Examples of Formation of Covalent Compounds

Formation of Fluorine Molecule

  1. The electrons arrangement of a fluorine atom is 2.7
  2. To achieve octet electrons arrangement, 2 fluorine atoms share 1 pair of electrons between each other.
  3. As a result, a covalent bond formed between the 2 atoms.
Formation of Oxygen Molecule
  1. The electrons arrangement of an oxygen atom is 2.6
  2. To achieve octet electrons arrangement, 2 fluorine atoms share 2 pair of electrons between each other.
  3. As a result, 2 covalent bonds formed between the 2 atoms.
 

Formation of Carbon Dioxide Molecule

 
  1. The electrons arrangement of an oxygen atom is 2.6 and the arrangement of the electrons of a hydrogen atom is 1.
  2. To achieve octet electrons arrangement, the oxygen atom share 2 pair of electrons with 2 hydrogen atoms.
  3. The hydrogen atoms achieve duplet electrons arrangement after sharing an electron with the oxygen atom.
  4. As a result, covalent bonds formed between the oxygen atom and the hydrogen atoms.

Number of Bond

Number of Bond

  1. There are 3 types of covalent bond:
    1. Single covalent bond – sharing of one pair of electrons
    2. Double covalent bond – sharing of two pairs of electrons
    3. Triple covalent bond – sharing of three pairs of electrons

Example

Number of electronsExample and type of covalent bond
1 pair

type of covalent bond: Single Bond

2 pair

type of covalent bond: Double Bond

3 pair

type of covalent bond: Triple Bond

Formation of Single Bond (Hydrogen Molecule)

Formation of Double Bond (Oxygen Molecule)

Formation of Triple Bond (Nitrogen Molecule)

Predicting the Molecular Formula of Covalent Compounds

  1. Like the formula of ionic compounds, the formula of most covalent compounds can be predicted by referring to the group in the periodic table of the elements in the compound.
  2. We can predict the formula of a covalent compound by referring to the valency of the elements in the compound if we know which group in the periodic table the element is located.
  3. The valency of an atom is the number of electrons receives of release to achieve octet electrons arrangement.
  4. For example, the electron arrangement of an oxygen atom is 2.6. To achieve the octet electrons arrangement, the oxygen atom needs to receive 2 electrons. Therefore, the valency of oxygen is 2.
  5. The table below shows the group of the elements, the valency of the elements and the predicted formula of covalent compounds formed among the elements.
Element that combinesFormula of the covalent compound
Element X fromValencyElement Y fromValency
Group 15
3
Group 15
3
 XY
Group 15
3
Group 16
2
 X2Y3
Group 15
3
Group 17
1
 XY3
Group 16
2
Group 16
2
 XY
Group 16
2
Group 17
1
 XY2
Group 17
1
Group 17
1
 XY
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