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.

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

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

Periodic table.

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
K.L.B. BOOK IIP. 9

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Groups 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 group.
Q/A: examples of elements of the same group.

Periodic table.

K.L.B. BOOK IIP. 9

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

R.M.M. and isotopes.

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

Supervised practice involving calculation of RMM from isotopic composition.

text book

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
K.L.B. BOOK IIP 16

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.

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
K.L.B. BOOK IIP 18

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.

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.

Discuss formation of compounds such as NaCl, MgO.
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.

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

Discuss formation of compounds such as
-Copper (I) Oxide.
-Copper (II) Oxide.
-Iron (II) Sulphate.
-Iron (III) Sulphate.

text book

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
K.L.B. BOOK IIPP 25-8

CHEMICAL FAMILIES

Alkali metals. Atomic and ionic radii 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.

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.

The periodic

K.L.B. BOOK IIPP 28-29

CHEMICAL FAMILIES

Ionisation energy of alkali metals.

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

Examine a table of elements, number of energy levels and their ionization energy.
Discuss the trend deduced from the table.

text book

K.L.B. BOOK II

CHEMICAL FAMILIES

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

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.
To write balanced equations for reaction of alkali metals with chlorine gas.

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.
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.

Chart ? comparative properties of Li, Na, K.

text book
Sodium, chlorine.

K.L.B. BOOK IIPP 30-31
K.L.B. BOOK IIP. 32

CHEMICAL FAMILIES

Compounds of alkali 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.

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

text book

K.L.B. BOOK II pp 33

CHEMICAL FAMILIES

Uses of alkali metals.

By the end of the lesson, the learner should be able to:
State uses of alkali metals.

Descriptive approach: Teacher elucidates uses of alkali metals.

text book

K.L.B. BOOK II pp 34

CHEMICAL FAMILIES

Alkaline Earth metals Atomic and ionic radii of alkaline earth metals.
Physical properties of alkaline earth metals.

By the end of the lesson, the learner should be able to:
Identify alkaline earth metals.

State changes in atomic and ionic radii of alkaline earth metals.
State and explain trends in physical properties of alkaline earth 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.

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 pp 34
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

PROPERTIES AND TRENDS ACROSS PERIOD THREE

Physical properties of elements in periods.

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




To compare electrical conductivity of elements in period 3

Group experiments- Construct electrical circuits incorporating a magnesium ribbon, then aluminum foil, then sulphur in turns.
The brightness of the bulb is noted in each case.
Discuss the observations in terms of delocalised electrons.

The periodic table.

K.L.B. BOOK IIP. 76

PROPERTIES AND TRENDS ACROSS PERIOD THREE

Physical properties of elements in period 3.
Chemical properties of elements in period 3.
Chemical properties of elements in the third period.
Oxides of period 3 elements.
Chlorides of period 3 elements.

By the end of the lesson, the learner should be able to:
To compare other physical properties of elements across period 3.
To compare reactions of elements in period 3 with oxygen.
To compare reactions of elements in period 3 with water
To identify bonds across elements in period 3.
To explain chemical behavior of their oxide.
To explain chemical behavior of their chlorides.
To describe hydrolysis reaction.

Analyse comparative physical properties presented in form of a table.
Explain the trend in the physical properties given.
Q/A: Products of reactions of Na, Mg, Al, P, & S with oxygen.
Discuss the trend in their reactivity; identify basic and acidic oxides.
Exercise ? balanced chemical equations for the above reactions.
Q/A: Review reaction of sodium, Mg, chlorine, with water.
Infer that sodium is most reactive metal; non-metals do not react with water.
Comparative analysis, discussion and explanation.

The periodic table.

K.L.B. BOOK II P. 77
K.L.B. BOOK II P. 84