THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Atomic and mass numbers.

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.

Exposition on new concepts;
Probing questions;
Brief discussion.

text book

K.L.B.
BOOK II

PP. 1-3

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

First twenty elements of the periodic table.
Isotopes.

By the end of the lesson, the learner should be able to:
List the first twenty elements of the periodic table.
Write chemical symbols of the first twenty elements of the periodic table.

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.

Periodic table.

K.L.B.
BOOK II

PP. 1-3

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Electronic configuration.
Electronic configuration in diagrams.

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.
Represent electronic configuration diagrammatically.

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

Periodic table.

text book

K.L.B.
BOOK II
P. 4





PP. 5-9
K.L.B.
BOOK II
PP. 5-8

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Periods of 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 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

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.
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.

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

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.

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.

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

Valencies of radicals.
Oxidation number.
Electronic configuration, ion formed, valency and oxidation number

By the end of the lesson, the learner should be able to:
Define a radical.
Recall the valencies of common radicals.
Relate electronic configuration, ion formed, valency and oxidation number of different elements.

Exposition ? teacher defines a radical, gives examples of radicals and exposes their valencies.
Students draw a table of radicals and their valencies.

Written exercise;
Exercise review.

text book
The periodic table.

K.L.B. BOOK IIP 18

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Chemical formulae of compounds. - Elements of equal 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.

Discuss formation of compounds such as NaCl, MgO.

text book

K.L.B. BOOK IIPP 19-20

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.
Balanced 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 balance chemical equations correctly.

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

Exposition;
Supervised practice.

text book

K.L.B. BOOK IIP 20
K.L.B. BOOK IIPP 24-25

THE STRUCTURE OF THE ATOM & THE PERIODIC TABLE

Balanced chemical equations.(contd)

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

Supervised practice;
Written exercise.

text book

K.L.B. BOOK IIPP 25-8

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.

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

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.

text book
Some alkaline earth metals.

K.L.B. BOOK IIP. 38

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.
Supervised practice.

Sodium, chlorine.
revision book

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

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

Halogens. Physical properties of halogens.
Comparative physical properties of halogens.
Chemical properties of halogens.

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.

Teacher demonstration: - To examine electrical properties of iodine, solubility in water of chlorine.

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

KLB BK II
P. 47

CHEMICAL FAMILIES

Equations of reaction of halogens with metals.
Reaction of halogens with water.

By the end of the lesson, the learner should be able to:
To write balanced chemical equations of reactions involving halogens.
To describe reaction of halogens with water and the results obtained.

Re-write word equations as chemical equations then balance them.
Supervised practice.
Bubbling chlorine gas through water.
Carry out litmus test for the water.
Explain the observations.

text book
Chlorine gas, litmus papers.

K.L.B. BOOK II P. 50
K.L.B. BOOK II P. 51

CHEMICAL FAMILIES
STRUCTURE & BONDING

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

By the end of the lesson, the learner should be able to:
To state uses of halogens and their compounds.

Teacher elucidates uses of halogens and their compounds.

text book

K.L.B. BOOK II pp 52

STRUCTURE & BONDING

Ionic bond representation.
Grant ionic structures.
Physical properties of ionic compounds.

By the end of the lesson, the learner should be able to:
Use dot and cross diagrams to represent ionic bonding.

Drawing diagrams of ionic bonds.

Chart- dot and cross diagrams.
Models for bonding.
Giant sodium chloride model.
text book

K.L.B. BOOK II P. 58

STRUCTURE & BONDING

Covalent bond.
Co-ordinate bond.
Molecular structure.
Trend in physical properties of molecular structures.
Giant atomic structure in diamond.
Giant atomic structure in graphite.

By the end of the lesson, the learner should be able to:
Explain the formation of covalent bond
Use dot and cross diagrams to represent covalent bond.
To describe van- der -waals forces.
To explain the trend in physical properties of molecular structures.

Exposition: Shared pair of electrons in a hydrogen molecule, H2O, NH3, Cl2, and CO2.
Drawing of dot-and-cross diagrams of covalent bonds.

Discuss comparative physical properties of substances. exhibiting molecular structure.
Explain variation in the physical properties.

text book
Sugar, naphthalene, iodine rhombic sulphur.
Diagrams in textbooks.

K.L.B. BOOK II PP 60-63
K.L.B. BOOK IIP 65

STRUCTURE & BONDING

Metallic bond. Uses of some metals.

By the end of the lesson, the learner should be able to:
To describe mutual electronic forces between electrons and nuclei.
To describe metallic bond.
To compare physical properties of metals.
To state uses of some metals.

Discussion:
Detailed analysis of comparative physical properties of metals and their uses.



Probing questions & brief explanations.

text book

K.L.B. BOOK IIP 70

PROPERTIES AND TRENDS ACROSS PERIOD THREE

Physical properties of elements in periods.
Physical properties of elements in period 3.
Chemical properties of elements in period 3.

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
SALTS

Chemical properties of elements in the third period.
Oxides of period 3 elements.
Chlorides of period 3 elements.
Types of salts.
Solubility of salts in water.

By the end of the lesson, the learner should be able to:
To compare reactions of elements in period 3 with water
Define a salt.
Describe various types of salts and give several examples in each case.

Q/A: Review reaction of sodium, Mg, chlorine, with water.
Infer that sodium is most reactive metal; non-metals do not react with water.

Descriptive approach. Teacher exposes new concepts.

The periodic table.
text book
Sulphates, chlorides, nitrates, carbonates of various metals.

K.L.B. BOOK II PP. 80-81
K.L.B. BOOK II P. 91

SALTS

Solubility of bases in water.
Methods of preparing various salts.

By the end of the lesson, the learner should be able to:
To test solubility of various bases in water.
To carry out litmus test on the resulting solutions.

Class experiments- Dissolve salts in 5cc of water.
Record the solubility in a table,
Carry out litmus tests.
Discuss the results.

Oxides, hydroxides, of various metals, litmus papers.
CuO, H2SO4, HCl, NaOH, PbCO3, dil HNO3.

K.L.B. BOOK IIPP. 94-95

SALTS

Direct synthesis of a salts.
Ionic equations.

By the end of the lesson, the learner should be able to:
To describe direct synthesis of a salt.
To write balanced equations for the reactions.

Group experiments- preparation of iron (II) sulphide by direct synthesis.
Give other examples of salts prepared by direct synthesis.
Students write down corresponding balanced equations.

Iron,
Sulphur
PbNO3, MgSO4 solutions.

K.L.B. BOOK II P. 104

SALTS

Effects of heat on carbonates.
Effects of heat on nitrates.
Effects of heat on sulphates.
Hygroscopy, Deliquescence and Efflorescence.
Uses of salts.

By the end of the lesson, the learner should be able to:
To state effects of heat on carbonates.
To predict products resulting from heating metal carbonates.
To define hygroscopic deliquescent and efflorescent salts.
To give examples of hygroscopic deliquescent and efflorescent salts.

Group experiments- To investigate effects of heat on Na2CO3, K2CO3, CaCO3, ZnCO3, PbCO3, e.t.c.
Observe various colour changes before, during and after heating.
Write equations for the reactions.

Prepare a sample of various salts.
Expose them to the atmosphere overnight.
Students classify the salts as hygroscopic, deliquescent and / or efflorescent.

Various carbonates.
Common metal nitrates.
Common sulphates.

K.L.B. BOOK II PP. 108-109
K.L.B. BOOK II P. 114