ACIDS, BASES AND SALTS.

Strength of acids. Acids in aqueous form.
pH values of acids. Electrical conductivities of aqueous acids.

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


Define an acid in terms of hydrogen ions.

Explain strength of acids in aqueous form in terms of number of hydrogen ions present.
Determine strength of acids using pH values.

Determine strengths of acids by comparing their electrical conductivities.

Classify acids as either strong or weak in terms of partial dissociations in aqueous solutions.

Class experiments: investigate reactions of magnesium and zinc carbonate with different acids.
Make and record observations in tabular form.
Make deductions from the observations.
Write relevant chemical equations and ionic equations.
Detailed discussion leading to the definition of an acid and explanation of strength of an acid.

Q/A: review determination of strength of acids using a litmus paper and pH scale.
Class / group experiments: record colour of universal indicator in
2M HCl and 2M ethanoic acid.
Set up voltameters of 2M HCl and 2M ethanoic acid in turns.
Record amounts of current .
Discuss the observations.
Write corresponding ionic equations.

Magnesium strip, zinc carbonate,
2M HCl,
2M H2SO4,
2M ethanoic acid.
Universal
indicator,
2M HCl,
2M ethanoic acid,
dry cells,
carbon electrodes,
milli-ammeters,
wires, switches etc.

K.L.B. BK IV
Pages 1-4
K.L.B. BK IV
Pages 4-6

ACIDS, BASES AND SALTS.

Definition of a base in terms of hydroxide ions.
Neutralization reaction.

By the end of the lesson, the learner should be able to:
Define a base in terms of hydroxide ions.
Determine the results of reaction of an acid and a base.

Teacher demonstration:
Dissolve calcium hydroxide in water.
Carry out litmus test on the resulting solution.
Discuss the results; hence define a base in terms of hydroxide ions.
Add 1M HCl to an aqueous solution of Calcium hydroxide drop wise until colour, change of the universal indicator is noted.
Write ionic equation for the reaction.

Red litmus paper, calcium hydroxide solid.
1M HCl,
Calcium hydroxide,
universal indicator.

K.L.B. BK IV
Pages 6-7

ACIDS, BASES AND SALTS.

Strength of bases.

By the end of the lesson, the learner should be able to:
Compare strengths of bases using pH values and electrical conductivity.


Classify bases/ alkali as either strong or weak in terms of complete / partial ionization.

Carry out pH tests of 2M NaOH and 2M ammonia solution using universal indicator solutions; and observe colour changes.

Carry out electrical conductivity tests of voltameters of the above solutions.

Discussion: relate number of hydroxide ions to pH values and electrical conductivity of bases.

2M NaOH,
2M ammonia solution, universal indicator solutions, dry cells,
carbon electrodes,
milliammeters,
wires, switches etc

K.L.B. BK IV
Pages 7-9

ACIDS, BASES AND SALTS.

Dissolving hydrogen chloride gas in water / methylbenzene.

By the end of the lesson, the learner should be able to:
Define a polar and a non-polar solvent.

Teacher demonstration:
Dissolving HCl gas in different solvents.
Discuss the observations.
Write down related balanced chemical equations.

Ammonia gas,
Methylbenzene, hydrogen chloride gas.

K.L.B. BK IV
Pages 9-11

ACIDS, BASES AND SALTS.

Dissolving ammonia gas in water/ methylbenzene.
Amphoteric oxides.
Precipitation Reactions.

By the end of the lesson, the learner should be able to:
Investigate effect of a polar / non-polar solvent on ammonia gas.
Define an amphoteric oxide.
Identify some amphoteric oxides.
Define a precipitate.
Write ionic equations showing formation of precipitates.

Carry out litmus tests on the resulting solution.
Make observations and deductions thereof.
Write down related balanced chemical equations.
Class experiment:
Carry out acid / base reactions with metal oxides.
Q/A: make deductions from the results.
Writing and balancing relevant equations.
Q/A: review definition of a salt.
Class experiment;
Add sodium carbonate or a suitable carbonate to various salt solutions containing Mg2+, Al3+, Ca2+, etc.
Make observations and discuss the results.

Ammonia gas,
Methylbenzene.
2M Nitric acid
2M NaOH,
HNO3.
Amphoteric oxides.
Soluble carbonates e.g. Na2CO3, K2CO3, (NH4)2CO3
Salt solutions containing Mg2+, Al3+, Ca2+, etc.

K.L.B. BK IV
Pages 11-12
K.L.B. BK IV
Pages 12-14

ACIDS, BASES AND SALTS.

Solubility of chlorides sulphites and sulphates.

By the end of the lesson, the learner should be able to:
Find out cations that form (in)soluble chlorides, sulphates and sulphites.

Class experiments: measure 2cc of 0.1M solution containing Pb2+ into a test tube.
Add drops of 2M NaCl solution.
(Later 2M Sodium Sulphate and 2M Sodium Sulphate).
Warm the mixture and make observations.
Repeat the procedure using other salt solutions containing other ions.
Tabulate the results.

0.1M solution containing Pb2+, 2M NaCl solution, 2M sodium sulphate, source of heating.

K.L.B. BK IV
Pages 16-17

ACIDS, BASES AND SALTS.

Equations for formation of insoluble chlorides, sulphites and sulphates.

By the end of the lesson, the learner should be able to:
Write down equations for formation of insoluble chlorides, sulphites and sulphates.

Q/A: review observations made in the above experiments.
Discuss the solubility of the cations.
Write relevant ionic equations.

student book

K.L.B. BK IV
Pages 17-18

ACIDS, BASES AND SALTS.

Complex ions.

By the end of the lesson, the learner should be able to:
Explain formation of complex ions.

Add drops of 2M sodium hydroxide / 2M ammonia solution to a solution containing Mg2+, Zn2+, etc.

Make observations and discuss the results.

2M Sodium hydroxide (2M ammonia solution),
solution containing Mg2+, Zn2+, etc.

K.L.B. BK IV
Pages 18-20

ACIDS, BASES AND SALTS.

Solubility of a salt at a given temperature.
Problems solving on solubility.
Effect of temperature on solubility of a solute in a solvent.

By the end of the lesson, the learner should be able to:
Define the term solubility.
Determine solubility of a given salt at room temperature.
Solve problems involving solubility of a solute in a solvent at a given temperature.
Investigate the effect of temperature on solubility of a solute in a solvent.

Q/A: review the terms saturated, unsaturated solutions & crystallization.
Class experiment: determine mass of a solute that dissolves in 100cc of water at room temperature.
Worked examples.
Supervised practice.
Written assignment.
Experiments involving solubility of KClO3 at different temperatures.
Note temperatures at which crystallization occurs.
Oral questions and discussion.

Suitable solutes.
Evaporating dish, watch glass, heating source, thermometer.
KClO3 thermometers, source of heat.

K.L.B. BK IV
Pages 20-21
K.L.B. BK IV
Pages 22-25

ACIDS, BASES AND SALTS.

Effects of various salts on soap.

By the end of the lesson, the learner should be able to:
Determine the effects of various salts on soap.

Group experiments: form soap lather in distilled water, tap water, rainwater, dilute solution of sodium chloride and solutions containing Ca2+ and Zn2+.
Note volume of soap that forms lather readily.

distilled water, tap water, rainwater, dilute solution of sodium chloride and solutions containing Ca2+ and Zn2+.

K.L.B. BK IV
Pages 25-27

ACIDS, BASES AND SALTS.
ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Removal of hardness of water.
Endothermic and Exothermic Reactions.

By the end of the lesson, the learner should be able to:
Identify ions for hardness of water.
Identify methods of removing hardness of water.
State merits & demerits of hard water.
To differentiate between endothermic & exothermic reactions.

Review results of above experiments.
Probing questions & brief discussion.
Assignment.
Investigate temperature changes in solution formation.
Obtain changes in temperature when ammonium nitrate and sodium hydroxide are dissolved in water, one at a time.

student book
Ammonium nitrate,
Sodium hydroxide, thermometers.

K.L.B. BK IV
Pages 27-29

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Energy level diagrams.

By the end of the lesson, the learner should be able to:
Represent endothermic reactions with exothermic reactions with energy level diagrams.

Probing questions on relative energies of reactants and products in endothermic and exothermic and endothermic reactions.

student book

K.L.B. BK IV
Pages 33-35

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Enthalpy Notation. Change of state.
CAT

By the end of the lesson, the learner should be able to:
Define the term enthalpy.
Distinguish positive enthalpy change from negative enthalpy change.

Determine the M.P/ B.P of a pure substance.

Q/A and brief discussion.
Class experiments: determine B.P of pure water/ M.P of naphthalene / ice.
Use experimental results to plot temperature-time graphs.
Explain the shape of the graphs.
Q/A: review kinetic theory of matter.
Apply the theory to explain the shape of the graph, and nature of bonding in substances.

Ice, naphthalene, thermometers, graph papers.

K.L.B. BK IV
Pages 35-39

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of solution.

By the end of the lesson, the learner should be able to:
Determine molar heat of solution of given substances.

Dissolve known masses of ammonia nitrate / sodium hydroxide in known volumes of water.
Determine temperature changes.
Calculate molar heat of solution. Supervised practice.

Ammonia nitrate / sodium hydroxide, thermometers.

K.L.B. BK IV
Pages 40-41

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of solution of H2SO4.

By the end of the lesson, the learner should be able to:
Determine molar heat of solution of H2SO4.

Dissolve some known volume of conc. H2SO4 in a given volume of water.
Note the change in temperature.
Work out the molar heat of solution of H2SO4.

Conc. H2SO4, thermometers.

K.L.B. BK IV
Pages 42-45

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Enthalpy of combustion. Enthalpy of combustion.

By the end of the lesson, the learner should be able to:
Define the term enthalpy of combustion.
Determine the enthalpy of combustion of ethanol.
Explain why actual heats of combustion are usually lower than the theoretical values.

Group experiments / teacher demonstration.

Obtain and record results.


Work out calculations.

Ethanol, distilled water, thermometer, clear wick, tripod stand and wire gauze.

K.L.B. BK IV
Pages 45-48

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Molar heat of displacement of ions.
Molar heat of solution of neutralization.
Standard enthalpy changes.

By the end of the lesson, the learner should be able to:
Define the term molar heat of solution of displacement of ions.
Determine the molar heat of solution of displacement of ions.
Define the term neutralization.
Determine the molar heat of neutralization of HCl with NaOH.
Define the term standard enthalpy change.
Denote standard enthalpy change with the correct notation.

Group experiments/ teacher demonstration.
Note steady temperature of solutions formed when zinc/ iron / magnesium reacts with copper sulphate solution.
Work out the molar heat of displacement of a substance from a solution of its ions.
Class experiments:
Neutralize 2M HCl of known volume with a determined volume of 1M / 2M sodium hydroxide.
Note highest temperature of the solution.
Work out the molar heat of neutralization.
Solve other related problems.
Assignment.
Exposition & brief discussion.

Zinc, iron, magnesium, copper sulphate solution.
2M HCl of known volume, 1M / 2M sodium hydroxide.
student book

K.L.B. BK IV
Pages 48-50
K.L.B. BK IV
Pages 54-56

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Hess?s Law.

By the end of the lesson, the learner should be able to:
State Hess?s law.

Solve problems related to Hess?s law.

Detailed discussion & guided discovery of the law.
Illustrations of energy cycles and energy levels leading to Hess?s law.
Worked examples.
Supervised practice
Written assignment.

student book

K.L.B. BK IV
Pages 56-57

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Heat of solution hydration energy and lattice energy.

By the end of the lesson, the learner should be able to:
Define the terms lattice energy and hydration energy.
Explain the relationship between heat of solution, hydration energy.
Solve related problems.

Exposition of new concepts.
Guided discovery of the relationship between heat solution hydration energy and lattice energy.
Worked examples.
Assignment.

student book

K.L.B. BK IV
Pages 60-64

ENERGY CHANGES IN PHYSICAL & CHEMICAL PROCESSES.

Heat values of fuels.
Environmental effects of fuels.

By the end of the lesson, the learner should be able to:
Define the term fuel.
Describe energy changes when a fuel undergoes combustion.
Outline factors considered when choosing a suitable fuel.
Outline some environmental effects of fuels.
Identify measures taken to reduce environmental
pollution.

Probing questions and brief discussion.
Q/A & open discussion.

student book

K.L.B. BK IV
Pages 64-66

RATES OF REACTION & REVERSIBLE REACTIONS.

Effect of concentration on rate of a reaction
Effect of time of reaction on the rate of reaction.

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





Explain the effects of change of concentration of reactants on a reaction.

Explain how the rate or reaction changes as the reaction proceed

Group experiments to investigate effect of concentration on rate of reaction using dil. HCl and magnesium ribbons.
Determine the time taken for reactions to be complete.
Calculation of concentration of HCl in moles per litre.
Discuss the observations and sketch illustrative graphs.

Group experiments: investigate volume of gas evolved when magnesium reacts with dilute HCl.
Collect evolved gas and sketch and illustrative graphs.
Discuss the results.

Portions of 2M HCl diluted with different volumes of water,
Stopwatches.
Magnesium ribbons, stopwatches, conical flask.
100cm3 0.5M HCl, syringes, stoppers, tubes and connectors.

K.L.B. BK IV
Pages 73-74
K.L.B. BK IV
Pages 75-79

ELECTRO-CHEMISTRY.

Redox reactions.
Oxidizing Numbers.

By the end of the lesson, the learner should be able to:
Describe redox reactions in terms of gain / loss of electrons.
Identify oxidizing / reducing agents involved in redox reactions.
Outline rules of assigning oxidation numbers.
Determine the oxidation numbers of an element in a given compound.
Explain the use of oxidation numbers in naming compounds.

Q/A: review cations, anions and charges.
Write down ionic half equations and identify reducing / oxidizing agents.
Exposition and giving specific examples.
Work out oxidizing number of elements in given compounds.
Copy and complete a table of compounds containing elements that more than one oxidation number.

student book

K.L.B. BK IV
Pages 108-9

ELECTRO-CHEMISTRY.

Displacement reactions.

By the end of the lesson, the learner should be able to:
Explain change of oxidation numbers during redox / displacement reactions. Arrange elements in order of their reducing power.

Class standard experiments: reacting metals with solutions containing metal ions.
Taking note of reactions and those that do not take place; and tabulating the results.

Metals: Ca, Na, Zn, Fe, Pb, and Cu.
Solutions containing Ca2+, Mg2+, Zn2+, Fe2+.

K.L.B. BK IV
Pages 116-120

ELECTRO-CHEMISTRY.

The oxidizing power of an element.

By the end of the lesson, the learner should be able to:
Arrange elements in order of their oxidizing power.

Teacher demonstration / group expts:
Adding halogens to solutions containing halide ions.
Tabulate the results.
Discuss the results and arrive at the oxidizing power series of halogens.

Halogens:
Cl2 (g),
Br2 (l),
I2 (s).

Halides:
KCl, KBr, KI.

K.L.B. BK IV
Pages 120-122

ELECTRO-CHEMISTRY.

Cell diagrams.
Standard Electrode Potentials.
Standard electrode potential series.

By the end of the lesson, the learner should be able to:
Define the terms electrode, potential and e.m.f. of an electrochemical cell.
Describe components of a cell diagram.
Draw cell diagrams using correct notations.
Identify standard conditions for measuring electrode potentials.
Define the term standard electrode potential of a cell.
Write half reactions of electrochemical cells.
Recall the order of standard electrode potentials.
Compare oxidizing and reducing powers of substances.

Teacher demonstration: Zinc/ copper cell.
Q/A & discussion: changes in oxidation numbers.
Exposition: cell diagram and deducing the direction of electron flow.
Descriptive and expository approaches: teacher exposes new concepts.
Q/A: review reactivity series, oxidizing agent, reducing agent.
Exposition: the order of standard electrode potentials.
Discussion: oxidizing and reducing powers of substances.

Zinc/ copper cell.
student book

K.L.B. BK IV
Pages 123-128
K.L.B. BK IV
Pages 131-133

ELECTRO-CHEMISTRY.

Emf of a cell.

By the end of the lesson, the learner should be able to:
Calculate emf of a cell using standard electrodes potentials.

Q/A: review half-cells.
Worked examples; supervised practice.
Assignment.

student book

K.L.B. BK IV
Pages 133-136

ELECTRO-CHEMISTRY.

Possibility of a reaction to take place.
Primary and secondary chemical cells.

By the end of the lesson, the learner should be able to:
Predict whether a reaction will take place or not using standard electrode potentials.
Describe the functioning of primary and secondary chemical cells.

Worked examples.
Oral exercise.
Assignment.
Exposition of new concepts and brief discussion

student book

K.L.B. BK IV
Pages 136-137

ELECTRO-CHEMISTRY.

Electrolysis of dilute NaCl.

By the end of the lesson, the learner should be able to:
Define the term electrolysis.
Explain the concept of preferential discharge of ions.

Teacher demonstration: electrolysis of dilute sodium chloride with carbon electrodes.
Test for gases collected.
Write down equations of reactions at each electrode.
Discussion: preferential discharge of ions at electrodes.

Dilute sodium chloride voltameter.

K.L.B. BK IV
Pages 141-144

ELECTRO-CHEMISTRY.

Electrolysis of brine.
Electrolysis of dilute sulphuric (VI) acid.
Factors affecting electrolysis.

By the end of the lesson, the learner should be able to:
Identify products of electrolysis of brine.
Identify products of electrolysis of dilute sulphuric (VI) acid.
Explain factors that affect electrolytic products discharged at electrodes.

Teacher demonstration/ group experiments.
Test for the products of electrolysis.
Write relevant equations.
Q/A: review the electrochemical series of elements.
Teacher writes down order of ease of discharge of ions at electrodes.
Discussion: other factors; giving suitable examples.

Brine voltameter.
Sulphuric acid voltameter.
student book

K.L.B. BK IV
Pages 144-146
K.L.B. BK IV
Pages 153-5

ELECTRO-CHEMISTRY.

Application of electrolysis.
Faraday?s law of electrolysis.

By the end of the lesson, the learner should be able to:
Describe some applications of electrolysis.
State Faraday?s law of electrolysis.
Solve problems related to Faraday?s law of electrolysis.

Probing questions and brief discussion on applications of electrolysis.
Practical assignment on electrolysis: electroplating an iron nail with a suitable metal.
Discuss above results, leading to Faraday?s law of electrolysis.
Worked examples.
Assignment.

Suitable voltameter.
Weighing balance, stop watch, copper sulphate voltameter.

K.L.B. BK IV
Pages 155-7

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Alkanols (Alcohols).

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



Identify the functional group of alkanols.

Explain formation of alkanol molecules.

Q/A: review alkanes, alkenes and alkynes.

Teacher exposes new concepts and links them with already known concepts.

student book

K.L.B. BK IV
Page 205

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Nomenclature of alkanols.
Isomerism in alkanols.

By the end of the lesson, the learner should be able to:
Name and draw the structure of simple alkanols.
Describe positional and chain isomerism in alkanols.
Explain formation of primary and secondary alkanols.

Guided discovery of naming system for alkanols.
Draw and name structures of alkanols.
Q/A: review the terms positional and chain isomerism.
Brief discussion on isomerism.
Oral exercise: naming given organic compounds.
Written exercise: writing structural formulae for isomers of organic compounds of a given molecular formula.

student book

K.L.B. BK IV
Pages 206-8

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Preparation of ethanol in the lab.
Physical properties of alkanols.

By the end of the lesson, the learner should be able to:
Describe preparation of ethanol in the laboratory.
Explain the physical properties of alkanols.

Group experiments / teacher demonstration.

Discuss the fermentation process.
Comparative evaluation of physical properties of alkanols.
Q/A & discussion on variation in physical properties of alkanols.

Calcium hydroxide solution, sugar solution, yeast.


student book

K.L.B. BK IV
Pages 210-11
K.L.B. BK IV
Page 212

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Chemical properties of alkanols.
Esters and esterification.

By the end of the lesson, the learner should be able to:
Describe some chemical reactions of alkanols.
Explain formation of esters.
Describe the esterification process.

Group experiments/ teacher demonstration to investigate combustion of ethanol and its reaction with metals.
Write corresponding chemical equations.
Teacher exposes and explains new concepts.
Assignment.

student book

K.L.B. BK IV
Pages 213-5

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Oxidation of ethanol. Uses of alkanols.

By the end of the lesson, the learner should be able to:
Explain oxidation of ethanol by an oxidizing agent.
State uses of alkanols.
Explain the effects of alcohol on human health

Q/A: review redox reactions, oxidizing and reducing agents.
Brief discussion: oxidation of ethanol using potassium (VII) manganate or potassium (VI) dichromate.
Write corresponding chemical equations.
Open discussion.

student book

K.L.B. BK IV
Pages 216-8

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Alkanoic (Carboxylic Acids).

By the end of the lesson, the learner should be able to:
Identify the functional group of alkanoic (carboxylic) acids.
Explain formation of alkanoic acid molecule.

Q/A: review functional group of alkanols.

Brief discussion.

student book

K.L.B. BK IV
Page 219

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Nomenclature of alkanoic acids.
Lab preparation of ethanoic acid.

By the end of the lesson, the learner should be able to:
Name and draw the structure of simple alkanoic acids.


Describe laboratory preparation of ethanoic acid.

Guided discovery of the naming system for alkanoic acids.
Teacher demonstration: prepare ethanoic acid in the lab.

Brief discussion on preparation of ethanoic acid.

Chart: homologous series of alkanoic acids.
Concentrated H2SO4, potassium manganate
(VII) Crystals, water bath.

K.L.B. BK IV
Pages 219-221
K.L.B. BK IV
Pages 221-223

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Physical properties of alkanoic acids.
Chemical properties of alkanoic acids.

By the end of the lesson, the learner should be able to:
Explain some physical properties of alkanoic acids.
Explain some chemical properties of alkanoic acids.

Compare physical properties of some alkanoic acids.
Discuss the difference in physical properties among alkanoic acids.
Group experiment: investigate some chemical properties of ethanoic acid.
Carry out tests and record observations in a table.

student book
Ethanoic acid, universal indicator, sodium carbonate, magnesium strip, ethanol, conc. H2SO4 and sodium hydroxide.

K.L.B. BK IV
Pages 223-4

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Chemical properties & Uses of alkanoic acids.
Soap preparation in the lab.

By the end of the lesson, the learner should be able to:
Write equations for chemical reactions involving acids.
State uses of alkanoic acids.
Describe soap preparation in the lab.

Review and discuss the observations above.
Write corresponding chemical equations.
Teacher elucidates uses of alkanoic acids.
Group experiments,
Answer questions based on the experiments already carried out.

student book

K.L.B. BK IV
Pages 225-7

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Cleaning action of soap.

By the end of the lesson, the learner should be able to:
Describe the nature of a soap molecule.
Explain the mode of action in cleaning.

Expository and descriptive approaches.
Answer oral questions.

student book

K.L.B. BK IV
Pages 230-232

ORGANIC CHEMISTRY II (ALKANES & ALKANOIC ACIDS)

Effects of hard / soft water on soap.
Soapless detergents.
Polymers and polymerization.

By the end of the lesson, the learner should be able to:
Explain the effects of hard/ soft water on soap.
Prepare soapless detergents in the lab.
State merits of soapless detergents over soaps.
Explain the concepts additional and condensation polymerization as methods of making synthetic polymers.
Identify some products of polymerization.
State merits and demerits of synthetic polymers over natural materials.

Group experiments: form soap lather in different solutions.
Deduce the effects of hard/ soft water on soap.
Teacher demonsration.
Brief discussion.

Teacher exposes and explains new concepts.

Detailed discussion.

Assignment.

Distilled water, tap water, rainwater, sodium chloride solution.
Calcium nitrate, Zinc Sulphate, etc.
student book

K.L.B. BK IV
Pages 232-235
K.L.B. BK IV
Pages 238-242

RADIOACTIVITY

Definition of radioactivity.
Alpha particles.

By the end of the lesson, the learner should be able to:
Define radioactivity, a nuclide and radioactive decay.
Differentiate between natural and artificial radioactivity.
State properties of alpha particles.
Describe methods of detecting alpha particles.

Q/A: Review the atomic structure.
Exposition: symbolic representation of an atom / nucleus.
Exposition: meaning of radioactivity and radioactive decay.
Discussion: artificial and natural radioactivity.

Q/A: position of helium in the periodic table.
Expository approach:

student book

K.L.B. BK IV
Pages 249-251

RADIOACTIVITY

Equations involving alpha particles.
Beta particles. Gamma rays.
Radioactive Half-Life.

By the end of the lesson, the learner should be able to:
Write down and balance equations involving alpha particles.
State properties of beta particles.
Define isotopes and isobars.
Write down balanced equations involving both alpha and beta particles.
State properties of gamma rays.
Define the term radioactive half-life. Solve problems relating to half ?life

Q/A: Review atomic and mass numbers.
Examples of balanced equations.
Supervised practice.
Q/A: Review isotopes.
Expository approach: teacher briefly exposes new concepts.
Examples of equations.
Supervised practice.
Assignment.
Teacher demonstration: Dice experiment.
Exposition of the term half-life.
Worked examples.
Written exercise

student book
Dice.

K.L.B. BK IV
Page 257

RADIOACTIVITY

Radioactive decay curve.
Nuclear fusion and nuclear fission. Applications of radioactivity.

By the end of the lesson, the learner should be able to:
Plot a radioactive decay curve to deduce the
half ?life from the curve.
Differentiate between nuclear fusion and nuclear fission.
Describe applications of radioactivity.

Drawing a radioactive decay curve inferring the half-life of the sample from the graph.
Exposition of new concepts accompanied by nuclear equations.
Brief discussion: Carbon dating, detecting leakage, medication, agriculture, industry; effect of static charges, etc.

Graph papers.
student book

K.L.B. BK IV
Pages 254-5