Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 2nd Term
Week: 1
Age: 15 years
Duration: 45 minutes
Subject: Chemistry
Curriculum Theme: Chemistry
Previous Lesson: Gas Laws: Gay-Lussac, Avogadro and Ideal Gas Equation.
Topic: CHEMICAL COMBINATION
Subject Matter: periodic table: first 20 elements, electronic configuration of atoms, types of strong bonds: ionic, covalent, coordinate covalent (dative) and metallic

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Identify the first 20 elements of the periodic table with their symbols.
Draw the electronic configuration for the first 20 elements.
Explain the formation and characteristics of ionic, covalent, coordinate covalent, and metallic bonds.
Compare the different types of strong chemical bonds using examples.

Affective Domain:

Appreciate the importance of electron arrangement in chemical bonding.
Show interest in understanding how atoms combine to form compounds.

Psychomotor Domain:

Construct electronic configurations for given elements.
Illustrate the formation of ionic and covalent bonds.
Place the first 20 elements correctly on a blank periodic table template.

Work collaboratively to identify elements and discuss bond types.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum
State Unified Scheme of Work
New School Chemistry for Senior Secondary Schools by Osei Yaw Ababio

Instructional Materials

The teacher will teach this lesson with the aid of:

Blank periodic table template
Models of atoms and molecules
Charts showing the periodic table and electronic configurations
Table salt (sodium chloride) as an example of an ionic compound

Rationale for the Lesson

This lesson helps pupils understand how elements interact and combine to form various substances around them. Understanding chemical bonding is important for explaining the properties of different materials and their uses in daily life.

Prerequisite/Previous Knowledge

Pupils should have a basic understanding of atoms, elements, protons, neutrons, and electrons from their Junior Secondary School science classes.

Lesson Content/Board Summary

CHEMICAL COMBINATION

The First 20 Elements of the Periodic Table

The periodic table arranges elements based on their atomic number. Knowing the first 20 elements is fundamental in chemistry.

The first 20 elements are:

Hydrogen (H)
Helium (He)
Lithium (Li)
Beryllium (Be)
Boron (B)
Carbon (C)
Nitrogen (N)
Oxygen (O)
Fluorine (F)
Neon (Ne)
Sodium (Na)
Magnesium (Mg)
Aluminium (Al)
Silicon (Si)
Phosphorus (P)
Sulphur (S)
Chlorine (Cl)
Argon (Ar)
Potassium (K)
Calcium (Ca)

Electronic Configuration of Atoms

Electronic configuration describes the arrangement of electrons in the energy shells or orbitals of an atom. Atoms combine to achieve a stable octet (8 electrons) or duplet (2 electrons for hydrogen and helium) in their outermost shell.

Electrons fill shells in a specific order: 2 electrons in the first shell (K), 8 in the second (L), and 8 in the third (M) for the first 20 elements.

Examples of electronic configurations:

Hydrogen (H, Z=1): 1
Helium (He, Z=2): 2
Lithium (Li, Z=3): 2, 1
Carbon (C, Z=6): 2, 4
Oxygen (O, Z=8): 2, 6
Neon (Ne, Z=10): 2, 8
Sodium (Na, Z=11): 2, 8, 1
Chlorine (Cl, Z=17): 2, 8, 7
Argon (Ar, Z=18): 2, 8, 8

Types of Strong Chemical Bonds

Strong chemical bonds are forces that hold atoms together to form molecules or compounds. They result from changes in the electronic configuration of atoms.

Ionic Bond (Electrovalent Bond)

An ionic bond is formed by the complete transfer of one or more electrons from a metal atom (which forms a positive ion or cation) to a non-metal atom (which forms a negative ion or anion). This transfer results in electrostatic attraction between oppositely charged ions.

Characteristics of ionic bonds:

Formed between metals and non-metals.
Involves transfer of electrons.
Results in charged ions held together by strong electrostatic forces.
Examples: Sodium chloride (NaCl), Magnesium oxide (MgO).

Covalent Bond

A covalent bond is formed by the mutual sharing of one or more pairs of electrons between two non-metal atoms. This sharing allows both atoms to achieve a stable electron configuration.

Characteristics of covalent bonds:

Formed between two non-metal atoms.
Involves sharing of electron pairs.
Can be single, double, or triple bonds depending on the number of shared electron pairs.
Examples: Hydrogen (H₂), Oxygen (O₂), Water (H₂O), Methane (CH₄).

Coordinate Covalent Bond (Dative Bond)

A coordinate covalent bond is a type of covalent bond where one atom contributes both electrons to the shared pair. The atom donating the electron pair is called the donor, and the atom accepting it is called the acceptor.

Characteristics of coordinate covalent bonds:

A special type of covalent bond.
Both shared electrons come from one atom.
Once formed, it is indistinguishable from a normal covalent bond.
Examples: Ammonium ion (NH₄⁺), Hydronium ion (H₃O⁺).

Metallic Bond

A metallic bond is the electrostatic attraction between positively charged metal ions (cations) and a “sea” of delocalised electrons. These delocalised electrons are not associated with any single atom or bond but are free to move throughout the entire metal structure.

Characteristics of metallic bonds:

Found in metals.
Involves a lattice of positive metal ions and a “sea” of mobile electrons.
Responsible for properties like electrical conductivity, thermal conductivity, malleability, and ductility of metals.
Examples: Copper metal, Iron metal, Aluminium metal.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to recall what an atom is and its basic components. The teacher then introduces the topic “CHEMICAL COMBINATION” by explaining that atoms often join together to form compounds.
Pupils’ Activity: Pupils respond to questions and listen attentively.
Learning Point: Pupils recall basic concepts of atoms and are introduced to the lesson topic.

Step 2: Periodic Table and First 20 Elements

Time: 8 minutes
Teaching Skill: Explanation/Identification
Teacher’s Activity: The teacher displays a chart of the periodic table and guides pupils to identify and name the first 20 elements, along with their symbols and atomic numbers. The teacher distributes blank periodic table templates.
Pupils’ Activity: Pupils identify the first 20 elements, state their symbols, and begin to fill the blank periodic table templates.
Learning Point: Pupils identify and list the first 20 elements and their symbols.

Step 3: Electronic Configuration

Time: 8 minutes
Teaching Skill: Demonstration/Explanation
Teacher’s Activity: The teacher explains what electronic configuration is and demonstrates how to draw the electronic configuration for selected elements (e.g., Na, Cl, O) using the 2,8,8 rule for the first 20 elements. The teacher guides pupils to draw configurations for other elements.
Pupils’ Activity: Pupils observe the demonstration, ask questions, and practice drawing electronic configurations for various elements.
Learning Point: Pupils understand and can draw electronic configurations for atoms.

Step 4: Ionic Bonding

Time: 7 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher explains ionic bonding as the complete transfer of electrons between a metal and a non-metal. Using diagrams, the teacher illustrates the formation of sodium chloride (NaCl) from sodium and chlorine atoms, showing the transfer of an electron and the formation of ions. The teacher also explains the characteristics of ionic bonds.
Pupils’ Activity: Pupils listen, observe the diagrams, and take notes. They may ask questions about the electron transfer process.
Learning Point: Pupils understand the formation and characteristics of ionic bonds.

Step 5: Covalent and Coordinate Covalent Bonding

Time: 7 minutes
Teaching Skill: Explanation/Comparison
Teacher’s Activity: The teacher explains covalent bonding as the sharing of electrons between non-metal atoms, using examples like H₂ or H₂O. The teacher then introduces coordinate covalent bonding as a special type of covalent bond where one atom donates both shared electrons, using the ammonium ion (NH₄⁺) as an example. The characteristics of both bond types are highlighted.
Pupils’ Activity: Pupils listen, observe illustrations (if any), and note the differences between simple covalent and coordinate covalent bonds.
Learning Point: Pupils understand the formation and characteristics of covalent and coordinate covalent bonds.

Step 6: Metallic Bonding

Time: 5 minutes
Teaching Skill: Explanation
Teacher’s Activity: The teacher explains metallic bonding as the attraction between positive metal ions and a “sea” of delocalised electrons. The teacher discusses how this unique bonding explains the properties of metals like electrical conductivity.
Pupils’ Activity: Pupils listen and relate the explanation to their knowledge of metal properties.
Learning Point: Pupils understand the concept and characteristics of metallic bonds.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

List the first 5 elements of the periodic table with their symbols.
Draw the electronic configuration for an atom with atomic number 12 (Magnesium).
Define an ionic bond and give an example.
Explain the difference between a covalent bond and a coordinate covalent bond.
State two characteristics of metallic bonds.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, reiterating the importance of electron arrangement in determining bond types. The teacher assigns homework, asking pupils to research everyday examples of substances formed by each type of bond.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils consolidate their learning and identify areas for further study.

Lesson Keywords

Periodic Table – A tabular arrangement of chemical elements, ordered by their atomic number, electron configurations, and recurring chemical properties.
Electronic Configuration – The distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.
Ionic Bond – A chemical bond formed between two ions with opposite charges. It involves the complete transfer of valence electrons from one atom to another.
Covalent Bond – A chemical bond that involves the sharing of electron pairs between atoms.
Coordinate Covalent Bond (Dative Bond) – A type of covalent bond in which one atom provides both electrons that form the shared pair.
Metallic Bond – The force of attraction between the valence electrons and the metal atoms. It is formed by the attraction between a sea of delocalised electrons and a lattice of positive metal ions.
Valence Electrons – Electrons in the outermost shell of an atom, involved in chemical bonding.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to predict bond types for more complex compounds or discuss the properties derived from each bond type. For those needing more support, the teacher can provide simplified diagrams, extra practice in drawing electronic configurations, or pair them with peers for collaborative learning.

Note for teachers using this lesson plan

Ensure that visual aids like periodic table charts and models are readily available. Encourage active participation through questions and practical exercises, especially when teaching electronic configuration and bond formation. Emphasize the connection between electron arrangement and the stability of atoms.