THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

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

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.
Define isotopes.
Give examples of isotopes.

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

text book
Periodic table.
Periodic table.

K.L.B.
BOOK II

PP. 1-3
K.L.B.
BOOK II
P. 4





PP. 5-8

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Electronic configuration.

By the end of the lesson, the learner should be able to:
Represent isotopes symbolically.
Define an energy level.
Describe electronic configuration in an atom.

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

Periodic table.

K.L.B.
BOOK II
P. 4





PP. 5-9

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Electronic configuration in diagrams.
Periods of the periodic table.

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

Supervised practice;
Written exercise.
Exposition ? Definition of a period.
Q/A: Examples of elements of the same period.

text book
Periodic table.

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

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
K.L.B. BOOK IIPP. 11-13

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Positive ions and ion formation.
Positive ions representation.

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.

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.

text book
Chart  ion model.

K.L.B. BOOK IIPP 14-15

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Negative ions and ion formation.

By the end of the lesson, the learner should be able to:
To define an anion.
To describe formation of negative ions symbolically.

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

Chart  ion model.

K.L.B. BOOK IIP 17

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Valencies of metals.
Valencie of non-metals.
Valencies of radicals.

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.
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.

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.
Periodic table.
text book

K.L.B. BOOK IIP 17

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Oxidation number.

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.

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

The periodic table.

K.L.B. BOOK IIvP 18

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Electronic configuration, ion formed, valency and oxidation number

By the end of the lesson, the learner should be able to:
Relate electronic configuration, ion formed, valency and oxidation number of different elements.

Written exercise;
Exercise review.

text book

K.L.B. BOOK IIP 18

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Chemical formulae of compounds. - Elements of equal valencies.
Chemical formulae of compounds. -Elements of unequal valencies.
Chemical formulae of compounds. -Elements of variable valencies.

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

Discuss formation of compounds such as NaCl, MgO.
Discuss formation of compounds such as MgCl2
Al (NO3)3
Discuss formation of compounds such as
-Copper (I) Oxide.
-Copper (II) Oxide.
-Iron (II) Sulphate.
-Iron (III) Sulphate.

text book

K.L.B. BOOK IIPP 19-20
K.L.B. BOOK IIP 20

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Chemical equations.

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

Review word equations;
Exposition of new concepts with probing questions;
Brief discussion.

text book

K.L.B. BOOK IIPP 21-23

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

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.
Chemical 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.
To describe reaction of alkali metals with water.

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.

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.

Chart ? comparative properties of Li, Na, K.
text book

K.L.B. BOOK IIPP 30-31

CHEMICAL FAMILIES

Reaction of alkali metals with chlorine gas.

By the end of the lesson, the learner should be able to:
To write balanced equations for reaction of alkali metals with chlorine gas.

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.

Sodium, chlorine.

K.L.B. BOOK IIP. 33

CHEMICAL FAMILIES

Compounds of alkali metals.
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:
Write chemical formulae for compounds of alkali metals.
Explain formation of hydroxides, oxides and chlorides of alkali metals.

State uses of alkali metals.
Identify alkaline earth metals.
State changes in atomic and ionic radii of alkaline earth metals.

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

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
text book
Some alkaline earth metals.

K.L.B. BOOK II pp 33
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.

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

Teacher demonstration: -
To show alkaline metals are good conductors of electric charge.

Alkaline earth metals.

K.L.B. BOOK IIP. 37

CHEMICAL FAMILIES

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.
Reaction of alkaline earth metals with chlorine gas.

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

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.
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.

text book
Some alkaline earth metals.
Sodium, chlorine.

K.L.B. BOOK IIP. 38
K.L.B. BOOK II P. 41

CHEMICAL FAMILIES

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 reactions of alkaline earth metals with dilute acids.

Changing word to chemical equations.
Supervised practice.

revision book

K.L.B. BOOK II PP. 43

CHEMICAL FAMILIES

Chemical formulae of alkaline earth metals.
Uses of some alkaline earth metals and their compounds.

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.
State uses 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.
Descriptive approach: Teacher elucidates uses of alkaline earth metals.

text book

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

CHEMICAL FAMILIES

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:
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.

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.

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

KLB BK II
P. 47
K.L.B. BOOK II P. 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