THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Atomic and mass numbers.
First twenty elements of the periodic table.

By the end of the lesson, the learner should be able to:
Name the subatomic particles in an atom.
Define atomic number and mass number of an atom.
Represent atomic and mass numbers symbolically.
List the first twenty elements of the periodic table.
Write chemical symbols of the first twenty elements of the periodic table.

Exposition on new concepts;
Probing questions;
Brief discussion.
Expository approach: referring to the periodic table, teacher exposes the first twenty elements.
Writing down a list of first twenty elements of the periodic table.

text book
Periodic table.

K.L.B.
BOOK II

PP. 1-3

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Isotopes.
Electronic configuration.
Electronic configuration in diagrams.

By the end of the lesson, the learner should be able to:
Define isotopes.
Give examples of isotopes.

Represent isotopes symbolically.
Define an energy level.
Describe electronic configuration in an atom.
Represent electronic configuration diagrammatically.

Exposition of definition and examples of isotopes.
Giving examples of isotopes.

Exposition ? teacher exposes new concepts about electronic configuration.
Written exercise.
Supervised practice;

Periodic table.

Periodic table.
text book

K.L.B.
BOOK II
P. 4





PP. 5-8
K.L.B.
BOOK II
P. 4





PP. 5-9

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Periods of the periodic table.

By the end of the lesson, the learner should be able to:
Identify elements of the same period.

Exposition ? Definition of a period.
Q/A: Examples of elements of the same period.

Periodic table.

K.L.B. BOOK IIP. 9

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Groups of the periodic table.
R.M.M. and isotopes.

By the end of the lesson, the learner should be able to:
Identify elements of the same period.
Calculate R.M.M. from isotopic composition.

Exposition ? definition of a group.
Q/A: examples of elements of the same group.
Supervised practice involving calculation of RMM from isotopic composition.

Periodic table.
text book

K.L.B. BOOK IIP. 9

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Positive ions and ion formation.
Positive ions representation.
Negative ions and ion formation.

By the end of the lesson, the learner should be able to:
To define an ion and a cation.

To represent formation of positive ions symbolically.
To define an anion.
To describe formation of negative ions symbolically.

Teacher gives examples of stable atoms.
Guided discovery that metals need to lose one, two or three electrons to attain stability.
Examples of positive ions.


Diagrammatic representation of cations.
Teacher gives examples of stable atoms.
Guided discovery of formation of negative ions.
Diagrammatic representation of anions.

text book
Chart  ion model.

K.L.B. BOOK IIPP 14-15
K.L.B. BOOK IIP 16

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Valencies of metals.

By the end of the lesson, the learner should be able to:
Recall valencies of metals among the first twenty elements in the periodic table.

Q/A to review previous lesson;
Exposition;
Guided discovery.

Periodic table.

K.L.B. BOOK IIP 17

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Valencie of non-metals.
Valencies of radicals.

By the end of the lesson, the learner should be able to:
Recall valencies of non-metals among the first twenty elements in the periodic table.
Define a radical.
Recall the valencies of common radicals.

Q/A to review previous lesson;
Exposition;
Guided discovery.
Exposition ? teacher defines a radical, gives examples of radicals and exposes their valencies.
Students draw a table of radicals and their valencies.

Periodic table.
text book

K.L.B. BOOK IIP 17

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Oxidation number.
Electronic configuration, ion formed, valency and oxidation number
Chemical formulae of compounds. - Elements of equal valencies.

By the end of the lesson, the learner should be able to:
Define oxidation number.
Predict oxidation numbers from position of elements in the periodic table.
Relate electronic configuration, ion formed, valency and oxidation number of different elements.
To derive the formulae of some compounds involving elements of equal valencies.

Q/A: Valencies.
Expose oxidation numbers of common ions.
Students complete a table of ions and their oxidation numbers.

Written exercise;
Exercise review.
Discuss formation of compounds such as NaCl, MgO.

The periodic table.
text book

K.L.B. BOOK IIvP 18
K.L.B. BOOK IIP 18

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Chemical formulae of compounds. -Elements of unequal valencies.

By the end of the lesson, the learner should be able to:
To derive the formulae of some compounds involving elements of unequal valencies.

Discuss formation of compounds such as MgCl2
Al (NO3)3

text book

K.L.B. BOOK IIPP 19-20

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Chemical formulae of compounds. -Elements of variable valencies.
Chemical equations.

By the end of the lesson, the learner should be able to:
To derive the formulae of some compounds involving elements of variable valencies.
To identify components of chemical equations.

Discuss formation of compounds such as
-Copper (I) Oxide.
-Copper (II) Oxide.
-Iron (II) Sulphate.
-Iron (III) Sulphate.
Review word equations;
Exposition of new concepts with probing questions;
Brief discussion.

text book

K.L.B. BOOK IIP 20

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Balanced chemical equations.
Balanced chemical equations.(contd)

By the end of the lesson, the learner should be able to:
To balance chemical equations correctly.

Exposition;
Supervised practice.
Supervised practice;
Written exercise.

text book

K.L.B. BOOK IIPP 24-25
K.L.B. BOOK IIPP 25-8

CHEMICAL FAMILIES

Alkali metals. Atomic and ionic radii of alkali metals
Ionisation energy of alkali metals.

By the end of the lesson, the learner should be able to:
Identify alkali metals.
State changes in atomic and ionic radii of alkali metals.
State changes in number of energy levels and ionisation energy of alkali metals.

Q/A to reviews elements of group I and their electronic configuration.
Examine a table of elements, their symbols and atomic & ionic radii.
Discussion & making deductions from the table.
Examine a table of elements, number of energy levels and their ionization energy.
Discuss the trend deduced from the table.

The periodic
text book

K.L.B. BOOK IIPP 28-29

CHEMICAL FAMILIES

Physical properties of alkali metals.

By the end of the lesson, the learner should be able to:
State and explain trends in physical properties of alkali metals.

Examine a table showing comparative physical properties of Li, Na, and K.
Q/A: Teacher asks probing questions as students refer to the table for answers.
Detailed discussion on physical properties of alkali metals.

Chart ? comparative properties of Li, Na, K.

K.L.B. BOOK IIPP 30-31

CHEMICAL FAMILIES

Chemical properties of alkali metals.
Reaction of alkali metals with chlorine gas.
Compounds of alkali metals.

By the end of the lesson, the learner should be able to:
To describe reaction of alkali metals with water.
To write balanced equations for reaction of alkali metals with chlorine gas.
Write chemical formulae for compounds of alkali metals.
Explain formation of hydroxides, oxides and chlorides of alkali metals.

Q/A: Review reaction of metals with water.
Writing down chemical equations for the reactions.
Deduce and discuss the order of reactivity down the group.
Teacher demonstration- reaction of sodium with chlorine in a fume chamber.
Q/A: Students to predict a similar reaction between potassium and chlorine.
Word and balanced chemical equations for various reactions.
Exercise: Completing a table of hydroxides, oxides and chlorides of alkali metals.
Discuss combination of ions of alkali metals with anions.

text book
Sodium, chlorine.

K.L.B. BOOK IIP. 32
K.L.B. BOOK II pp 33

CHEMICAL FAMILIES

Uses of alkali metals.
Alkaline Earth metals Atomic and ionic radii of alkaline earth metals.

By the end of the lesson, the learner should be able to:
State uses of alkali metals.
Identify alkaline earth metals.
State changes in atomic and ionic radii of alkaline earth metals.

Descriptive approach: Teacher elucidates uses of alkali metals.
Q/A: Elements of group I and their electron configuration.
Examine a table of elements, their symbols and atomic & ionic radii.
Make deductions from the table.

text book
Some alkaline earth metals.

K.L.B. BOOK II pp 34

CHEMICAL FAMILIES

Physical properties of alkaline earth metals.

By the end of the lesson, the learner should be able to:
State and explain trends in physical properties of alkaline earth metals.

Examine a table showing comparative physical properties of Be, Mg, Ca.
Q/A: Teacher asks probing questions as students refer to the table for answers.
Detailed discussion of physical properties of alkaline earth metals.

Some alkaline earth metals.

K.L.B. BOOK II P. 35

CHEMICAL FAMILIES

Electrical properties of alkaline earth metals.
Chemical properties of alkaline earth metals. Reaction of alkaline earth metals with oxygen.
Chemical properties of alkaline earth metals. Reaction of alkaline earth metals with water.

By the end of the lesson, the learner should be able to:
To describe electrical properties of alkaline earth metals.
To describe reaction of alkaline earth metals with oxygen
To describe reaction of alkaline earth metals with water.

Teacher demonstration: -
To show alkaline metals are good conductors of electric charge.
Q/A: Review reactions of Mg, Ca, with oxygen.
The corresponding word and then chemical equations are then written and their correctness verified by the teacher.
Q/A: Review reaction of metals with water.
Writing down word and balanced chemical equations for the reactions.
Deduce and discuss the order of reactivity down the group.

Alkaline earth metals.
text book
Some alkaline earth metals.

K.L.B. BOOK IIP. 37
K.L.B. BOOK IIP. 39

CHEMICAL FAMILIES

Reaction of alkaline earth metals with chlorine gas.
Reaction of alkaline earth metals with dilute acids.

By the end of the lesson, the learner should be able to:
To write balanced equations for reaction of alkaline earth metals with chlorine gas.
To write balanced equations for reactions of alkaline earth metals with dilute acids.

Teacher demonstration- Reaction of sodium with chlorine in a fume chamber.
Q/A: Students to predict a similar reaction between potassium and chlorine.
Word and balanced chemical equations for various reactions.
Supervised practice.
Changing word to chemical equations.

Sodium, chlorine.
revision book

K.L.B. BOOK II P. 41

CHEMICAL FAMILIES

Chemical formulae of alkaline earth metals.

By the end of the lesson, the learner should be able to:
Write chemical formulae for compounds of alkaline earth metals.
Explain formation of hydroxides, oxides and chlorides of alkaline earth metals.

Exercise: Completing a table of hydroxides, oxides and chlorides of alkaline earth metals.
Discuss combination of ions of alkaline earth metals with anions.

text book

K.L.B. BOOK II PP. 45-47

CHEMICAL FAMILIES

Uses of some alkaline earth metals and their compounds.
Halogens. Physical properties of halogens.
Comparative physical properties of halogens.
Chemical properties of halogens.
Equations of reaction of halogens with metals.

By the end of the lesson, the learner should be able to:
State uses of alkaline earth metals.
Identify halogens in the periodic table.
Give examples of halogens.
Identify physical states of halogens.
To state and explain the trends in physical properties of halogens.
To describe laboratory preparation of chlorine gas.
To describe reaction of halogens with metals.
To write balanced chemical equations of reactions involving halogens.

Descriptive approach: Teacher elucidates uses of alkaline earth metals.
Teacher demonstration: - To examine electrical properties of iodine, solubility in water of chlorine.
Examine a comparative table of physical properties of halogens.
Discuss the deductions made from the table.
Teacher demonstration: - preparation of chlorine gas.
Reaction of chlorine and iron wool.
Reaction of bromine and iron wool.
Reaction of iodine and iron wool.
Observe the rate of these reactions; hence deduce order of their reactivity of halogens.
Re-write word equations as chemical equations then balance them.
Supervised practice.

text book
Iodine crystals, electrical wire, a bulb.
Chlorine, iron wool, bromine.
text book

K.L.B. BOOK II PP. 45-47
K.L.B. BOOK IIPP. 48-50

CHEMICAL FAMILIES

Reaction of halogens with water.

By the end of the lesson, the learner should be able to:
To describe reaction of halogens with water and the results obtained.

Bubbling chlorine gas through water.
Carry out litmus test for the water.
Explain the observations.

Chlorine gas, litmus papers.

K.L.B. BOOK II P. 51

CHEMICAL FAMILIES

Some uses of halogens and their compounds.
Noble Gases. Comparative physical properties of noble gases.
Uses of noble gases.

By the end of the lesson, the learner should be able to:
To state uses of halogens and their compounds.
To describe physical properties of noble gases.
To explain physical properties of noble gases.
State uses of noble gases.

Teacher elucidates uses of halogens and their compounds.
Make A comparative analysis of tabulated physical properties of noble gases.
Teacher elucidates uses of noble gases.

text book

K.L.B. BOOK II pp 52