STRUCTURE & BONDING

Chemical bonds. Ionic bond.

By the end of the lesson, the learner should be able to:
Describe role of valence electrons in determining chemical bonding.


Explain formation of ionic bonding.

Q/A: Review valence electrons of atoms of elements in groups I, II, III, VII and VIII.
Q/A: Review group I and group VII elements.
Discuss formation of ionic bond.

text book

K.L.B. BOOK IIP54




PP 57-58

STRUCTURE & BONDING

Ionic bond representation.
Grant ionic structures.

By the end of the lesson, the learner should be able to:
Use dot and cross diagrams to represent ionic bonding.
Describe the crystalline ionic compound.
Give examples of ionic substances.

Drawing diagrams of ionic bonds.
Discuss the group ionic structures of NaCl.
Teacher gives examples of other ionic substances: KNO3, potassium bromide, Ca (NO3)2, sodium iodide.

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

K.L.B. BOOK II P. 58
K.L.B. BOOK II PP 56-58

STRUCTURE & BONDING

Physical properties of ionic compounds.
Covalent bond.

By the end of the lesson, the learner should be able to:
Describe physical properties of ionic compounds.
Explain the differences in the physical properties of ionic compounds.
Explain the formation of covalent bond
Use dot and cross diagrams to represent covalent bond.

Analyse tabulated comparative physical properties of ionic compounds.

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

text book

K.L.B. BOOK IIPP 58-59
K.L.B. BOOK II PP 60-63

STRUCTURE & BONDING

Co-ordinate bond.

By the end of the lesson, the learner should be able to:
To describe the co-ordinate bond
To represent co-ordinate bond diagrammatically.

Exposition- teacher explains the nature of co-ordinate bond.
Students represent co-ordinate bond diagrammatically.

text book

K.L.B. BOOK II P 65

STRUCTURE & BONDING

Molecular structure.

By the end of the lesson, the learner should be able to:
To describe the molecular structure.
To give examples of substance exhibiting molecular structure

Discussion ? To explain formation of the giant structure and give examples of substance exhibiting molecular structure.

text book

K.L.B. BOOK IIP 65

STRUCTURE & BONDING

Trend in physical properties of molecular structures.

By the end of the lesson, the learner should be able to:
To describe van- der -waals forces.
To explain the trend in physical properties of molecular structures.

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

Sugar, naphthalene, iodine rhombic sulphur.

K.L.B. BOOK IIP 65

STRUCTURE & BONDING

Giant atomic structure in diamond.

By the end of the lesson, the learner should be able to:
To describe giant atomic structure in diamond.
To state uses of diamond.

Diagrammatic representation of diamond.
Discuss uses of diamond.

Diagrams in textbooks.

K.L.B. BOOK II P 69

STRUCTURE & BONDING

Giant atomic structure in graphite.

By the end of the lesson, the learner should be able to:
To describe giant atomic structure in graphite.
To state uses of graphite.

Diagrammatic representation of graphite.

Discuss uses of graphite.

Diagrams in textbooks.

K.L.B. BOOK II pp 69

STRUCTURE & BONDING
PROPERTIES AND TRENDS ACROSS PERIOD THREE

Metallic bond. Uses of some metals.
Physical properties of elements in periods.

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.




To compare electrical conductivity of elements in period 3

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



Probing questions & brief explanations.

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.

text book
The periodic table.

K.L.B. BOOK IIP 70
K.L.B. BOOK IIP. 76

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 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.

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.

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.

The periodic table.

K.L.B. BOOK II P. 77
K.L.B. BOOK II PP. 79-80

PROPERTIES AND TRENDS ACROSS PERIOD THREE

Chemical properties of elements in the third period.

By the end of the lesson, the learner should be able to:
To compare reactions of elements in period 3 with water

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

The periodic table.

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

PROPERTIES AND TRENDS ACROSS PERIOD THREE

Chemical properties of elements in the third period.

By the end of the lesson, the learner should be able to:
To compare reactions of elements in period 3 with water

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

The periodic table.

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

PROPERTIES AND TRENDS ACROSS PERIOD THREE

Oxides of period 3 elements.
Chlorides of period 3 elements.

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

Comparative analysis, discussion and explanation.

The periodic table.

K.L.B. BOOK II P. 84
K.L.B. BOOK II PP. 77-78

SALTS

Types of salts.

By the end of the lesson, the learner should be able to:
Define a salt.
Describe various types of salts and give several examples in each case.

Descriptive approach. Teacher exposes new concepts.

text book

K.L.B. BOOK II P. 91

SALTS

Solubility of salts in water.

By the end of the lesson, the learner should be able to:
To test solubility of various salts in cold water/warm water.

Class experiments- Dissolve salts in 5 cc of water.
Record the solubility in a table,
Analyse the results.

Sulphates, chlorides, nitrates, carbonates of various metals.

K.L.B. BOOK II PP. 92-93

SALTS

Solubility of bases in water.

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.

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

SALTS

Solubility of bases in water.

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.

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

SALTS

Methods of preparing various salts.

By the end of the lesson, the learner should be able to:
To describe various methods of preparing some salts.

Experimental and descriptive treatments of preparation of salts e.g. ZnSO4, CuSO4, NaCl and Pb(NO3)2.

CuO, H2SO4, HCl, NaOH, PbCO3, dil HNO3.

K.L.B. BOOK II pp96

SALTS

Direct synthesis of a salts.

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

K.L.B. BOOK II P. 104

SALTS

Direct synthesis of a salts.

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

K.L.B. BOOK II P. 104

SALTS

Ionic equations.

By the end of the lesson, the learner should be able to:
To identify spectator ions in double decomposition reactions.
To write ionic equations correctly.

Q/A: Ions present in given reactants.
Deduce the products of double decomposition reactions.
Give examples of equations.
Supervised practice.

PbNO3, MgSO4 solutions.

K.L.B. BOOK II

SALTS

Effects of heat on carbonates.

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.

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.

Various carbonates.

K.L.B. BOOK II PP. 108-109

SALTS

Effects of heat on nitrates.

By the end of the lesson, the learner should be able to:
To state effects of heat on nitrates.
To predict products resulting from heating metal nitrates.

Group experiments- To investigate effects of heat on various metal nitrates.
Observe various colour changes before, during and after heating.
Write equations for the reactions.

Common metal nitrates.

K.L.B. BOOK II PP. 110-111

SALTS

Effects of heat on sulphates.

By the end of the lesson, the learner should be able to:
To state effects of heat on sulphates.
To predict products results from heating metal sulphates.

Group experiments- To investigate effects of heat on various sulphates.
Observe various colour changes before, during and after heating.
Write equations for the reactions.

Common sulphates.

K.L.B. BOOK II P. 113

SALTS

Hygroscopy, Deliquescence and Efflorescence.

By the end of the lesson, the learner should be able to:
To define hygroscopic deliquescent and efflorescent salts.
To give examples of hygroscopic deliquescent and efflorescent salts.

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

K.L.B. BOOK II P. 114

SALTS

Uses of salts.

By the end of the lesson, the learner should be able to:
To state uses of salts

Teacher elucidates uses of salts.

K.L.B. BOOK II P. 114

EFFECTS OF AN ELECTRIC CURRENT ON SUBSTANCES.

Electrical conductivity.

By the end of the lesson, the learner should be able to:
To test for electrical conductivities of substances.

Group experiments- to identify conductors and non-conductors.
Explain the difference in (non) conductivities.

Various solids, bulb, battery, & wires.

K.L.B. BOOK II PP. 118-119