Matter and Chemical Reactions

Chemical Bonding -Role of valence electrons in bond formation
Chemical Bonding -Ionic bonding in NaCl, MgF₂ and Al₂O₃

By the end of the lesson, the learner should be able to:
- Explain the role of valence electrons in chemical bond formation
- Identify which atoms lose, gain or share electrons to achieve stability
- Connect valence electron behaviour to everyday materials such as why salt dissolves in water and why metals conduct electricity

In groups, learners are guided to:
- Search for information on the role of valence electrons using textbooks or online resources
- Complete the flow chart on how valence electrons assist in stabilising atoms
- Discuss with peers how metals, non-metals and noble gases behave differently due to their valence electrons
- Write brief notes on the role of valence electrons in bond formation

How do valence electrons determine the type of chemical bond an atom will form?

- Humming Bird General Science pg. 189
- Digital devices
- Internet access
- Reference books
- Plasticine or beads for modelling

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Chemical Bonding -Covalent bonding in H₂, HCl, H₂O, NH₃ and O₂
Chemical Bonding -Dative-covalent bond in NH₄⁺

By the end of the lesson, the learner should be able to:
- Describe the formation of single, double and triple covalent bonds through the sharing of electrons
- Draw dot-and-cross diagrams to illustrate covalent bonding in H₂, H₂O, O₂ and CO₂
- Connect covalent bonding to everyday substances such as water, oxygen in the air and carbon dioxide produced during respiration

In groups, learners are guided to:
- Study Figures 2.31–2.34 on covalent bonding in water, oxygen, iodine and carbon dioxide
- Draw dot-and-cross diagrams for H₂, H₂O, O₂, CO₂ and HCl
- Model a covalent bond in CO₂ using toothpicks and beads
- Discuss the difference between single, double and triple covalent bonds

How does the sharing of electrons between non-metal atoms lead to the formation of a covalent bond?

- Humming Bird General Science pg. 189
- Toothpicks and beads for modelling
- Digital devices
- Reference books
- Internet access

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Chemical Bonding -Hydrogen bonds and Van der Waals forces
Chemical Bonding -Metallic bonding and metallic structure

By the end of the lesson, the learner should be able to:
- Explain the formation of hydrogen bonds between water molecules
- Describe Van der Waals forces as weak intermolecular attractions
- Connect hydrogen bonding to real-life properties of water such as its high boiling point, surface tension and its role as a biological solvent

In groups, learners are guided to:
- Study Figure 2.36 on hydrogen bonding in water molecules
- Discuss the relative strengths of Van der Waals forces, hydrogen bonds and covalent bonds
- Model covalent and hydrogen bonds in water using beads and strings
- Discuss how these forces explain physical properties of molecular substances

How do hydrogen bonds and Van der Waals forces influence the physical properties of everyday substances like water?

- Humming Bird General Science pg. 189
- Beads and strings for modelling
- Digital devices
- Reference books
- Metal samples

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Chemical Bonding -Giant ionic, simple molecular and giant atomic structures

By the end of the lesson, the learner should be able to:
- Distinguish between giant ionic, simple molecular and giant atomic structures
- Describe the physical properties of substances with each structure type
- Connect structural types to real-life choices such as using diamond in cutting tools, graphite as a lubricant and NaCl as a food preservative

In groups, learners are guided to:
- Study Tables 2.32–2.34 on properties of substances with ionic, molecular and giant atomic structures
- Study Figure 2.28 on the giant ionic lattice structure of NaCl
- Study Figures 2.37A and 2.37B on graphite and diamond structures
- Discuss the differences in properties arising from different structures

How does the structure of a substance determine its physical properties and practical uses?

- Humming Bird General Science pg. 189
- Digital devices
- Reference books
- Charts showing molecular structures

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Chemical Bonding -Uses of diamond, graphite and aluminium
Acids, Bases and Salts -Meaning and definition of acids and bases

By the end of the lesson, the learner should be able to:
- Explain the uses of diamond, graphite and aluminium in relation to their bond types and structures
- Select appropriate materials for specific applications based on their physical properties
- Connect material selection to everyday engineering decisions such as choosing aluminium for aircraft, graphite for pencils and diamond for drilling

In groups, learners are guided to:
- Study Table 2.35 on uses of diamond, graphite and aluminium in relation to their bond types
- Work through the three engineering scenarios in the course book to select the best material
- Sensitise the community on the use and care of aluminium cookware
- Discuss and share findings with peers

How does understanding the bond type and structure of a material help engineers choose the right material for each job?

- Humming Bird General Science pg. 189
- Digital devices
- Reference books
- Aluminium cookware samples
- Humming Bird General Science pg. 208
- Phenolphthalein indicator
- Hydrochloric acid
- Sodium hydroxide solution
- Beakers and stirring rods

- Oral questions - Observation - Written tests

Matter and Chemical Reactions

Acids, Bases and Salts -Classifying substances using the universal indicator and pH chart
Acids, Bases and Salts -Role of acids and bases in biological processes

By the end of the lesson, the learner should be able to:
- Use the universal indicator and pH chart to classify substances as acidic, neutral or alkaline
- Describe the colour changes of the universal indicator across the pH scale
- Connect pH knowledge to everyday decisions such as testing soil pH for farming, checking swimming pool water and reading food labels

In groups, learners are guided to:
- Carry out Hands-on Activity 2 testing bleach, vinegar, antacids, soda, juices, water, wood ash and lemon using universal indicator
- Match observed colours against the pH chart
- Study Tables 2.40 and 2.41 on colours of substances in universal indicator
- Discuss and share findings with peers

How does the pH of a substance determine whether it is safe or harmful to use in food, farming or cleaning?

- Humming Bird General Science pg. 208
- Universal indicator solution
- pH chart
- Test tubes and droppers
- Various household substances
- Test tubes and test tube rack
- Pepsin suspension
- Egg albumen
- Hydrochloric acid
- Limewater and straws

- Oral questions - Observation - Written tests

Matter and Chemical Reactions

Acids, Bases and Salts -Reaction of acids with bases (neutralisation)

By the end of the lesson, the learner should be able to:
- Describe the neutralisation reaction between an acid and a base to produce a salt and water
- Write balanced chemical equations for acid-base neutralisation reactions
- Relate neutralisation to real-life situations such as using antacids to neutralise excess stomach acid and liming acidic soils to improve crop production

In groups, learners are guided to:
- Carry out Hands-on Activity on titration of hydrochloric acid with sodium hydroxide using phenolphthalein indicator
- Identify the products of the neutralisation reaction
- Write the balanced equation for NaOH + HCl
- Discuss other examples of neutralisation reactions in daily life

Why is the neutralisation reaction between acids and bases important in medicine, agriculture and industry?

- Humming Bird General Science pg. 208
- Burette and clamp
- Pipette and filler
- Phenolphthalein indicator
- Hydrochloric acid
- Sodium hydroxide solution

- Oral questions - Observation - Written tests

Matter and Chemical Reactions

Acids, Bases and Salts -Reaction of acids with carbonates
Acids, Bases and Salts -Reaction of acids with metals

By the end of the lesson, the learner should be able to:
- Describe the reaction of an acid with a metal carbonate to produce a salt, carbon dioxide and water
- Write balanced chemical equations for acid-carbonate reactions
- Connect acid-carbonate reactions to real-life processes such as the fizzing of antacid tablets and the weathering of limestone buildings

In groups, learners are guided to:
- Carry out Hands-on Activity 7 on the reaction of zinc carbonate with dilute nitric acid
- Test the gas produced using limewater
- Identify the products of the reaction
- Write the balanced equation for the reaction and discuss with peers

What happens when an acid reacts with a carbonate, and where do we see this reaction in everyday life?

- Humming Bird General Science pg. 208
- Zinc carbonate
- Dilute nitric acid
- Limewater
- Delivery tube and conical flask
- Digital devices
- Magnesium ribbon
- Dilute hydrochloric acid
- Conical flask and gas syringe
- Universal indicator
- Burning splint

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Acids, Bases and Salts -Classifying salts by behaviour when exposed to air
Acids, Bases and Salts -Applications of salts in daily life

By the end of the lesson, the learner should be able to:
- Distinguish between hygroscopic, deliquescent and efflorescent salts
- Describe what happens to sodium hydroxide, calcium chloride and sodium carbonate when exposed to air
- Connect salt behaviour to practical storage decisions such as keeping salt containers tightly sealed and using desiccants in packaging

In groups, learners are guided to:
- Carry out Hands-on Activity on classifying salts using petri dishes of sodium hydroxide, calcium chloride and sodium carbonate exposed to air
- Observe and record changes after one hour
- Discuss the differences between hygroscopy, deliquescence and efflorescence
- Write notes in exercise books and share with peers

How does the behaviour of salts when exposed to air affect how we store them at home and in industry?

- Humming Bird General Science pg. 208
- Petri dishes
- Sodium hydroxide pellets
- Calcium chloride crystals
- Sodium carbonate crystals
- Digital devices
- Internet access
- Reference books
- Charts and pictures

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Acids, Bases and Salts -Effects of salts on the environment and human health
Rates of Reactions -Meaning of the rate of a chemical reaction

By the end of the lesson, the learner should be able to:
- Explain the effects of salts on water bodies through eutrophication, on soil through salinisation and on air through salt-dust pollution
- Describe the health risks of excessive salt intake including high blood pressure
- Connect environmental and health literacy to community awareness campaigns on safe salt use in food and farming

In groups, learners are guided to:
- Study Figure 2.52 on the process of eutrophication
- Research the effect of salts on soil in irrigated areas using digital devices
- Research salt-dust contribution to air pollution in coastal areas
- Organise a community session on the dangers of excessive salt intake and demonstrate safe alternatives using the project activity

How does excessive use of salts in farming and food affect the environment and human health?

- Humming Bird General Science pg. 208
- Digital devices
- Internet access
- Reference books
- Pamphlets on salt and blood pressure
- Humming Bird General Science pg. 231
- Conical flask and balloon
- Baking soda and vinegar
- Magnesium ribbon
- Bunsen burner
- Stopwatch

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Rates of Reactions -Performing experiments to measure reaction rates

By the end of the lesson, the learner should be able to:
- Measure the rate of a reaction by recording the volume of gas produced or the change in mass over time
- Compare the reaction rates of sodium and calcium with water
- Connect rate measurement techniques to industrial quality control processes such as monitoring reaction progress in pharmaceutical manufacturing

In groups, learners are guided to:
- Carry out Hands-on Activity on comparing reaction rates of sodium and calcium with water
- Carry out the rate of precipitation experiment between sodium sulphate and barium chloride
- Record time taken for each reaction and compare results using Table 2.45
- Draw graphs of volume of gas or mass change against time and discuss trends

How can we measure and compare the rates of different chemical reactions in the laboratory?

- Humming Bird General Science pg. 231
- Sodium metal and calcium
- Beakers of water
- Sodium sulphate solution
- Barium chloride solution
- Stopwatch

- Oral questions - Observation - Written assignments

Matter and Chemical Reactions

Rates of Reactions -Effect of concentration on reaction rate
Rates of Reactions -Effect of temperature on reaction rate

By the end of the lesson, the learner should be able to:
- Explain how increasing concentration increases the rate of a reaction
- Carry out an experiment to investigate the effect of concentration of hydrochloric acid on the rate of dissolving magnesium ribbon
- Connect concentration effects to practical situations such as why stronger bleach removes stains faster and why diluting medicines changes their effectiveness

In groups, learners are guided to:
- Carry out Hands-on Activity 7 on the effect of concentration using four conical flasks with different concentrations of hydrochloric acid and magnesium ribbon
- Record time for ribbon to disappear for each concentration
- Draw a graph of concentration against time
- Discuss findings with peers

How does changing the concentration of a reactant affect how fast a chemical reaction occurs?

- Humming Bird General Science pg. 231
- Conical flasks and labels
- Hydrochloric acid (2M)
- Magnesium ribbon
- Measuring cylinder
- Stopwatch
- Conical flasks
- Sodium thiosulphate solution
- Hydrochloric acid
- Thermometer and stopwatch
- White paper with cross

- Oral questions - Observation - Written tests

Matter and Chemical Reactions

Rates of Reactions -Effect of surface area on reaction rate
Rates of Reactions -Effect of catalysts on reaction rate

By the end of the lesson, the learner should be able to:
- Explain how increasing surface area increases the rate of a reaction by exposing more particles to contact
- Carry out an experiment comparing the rate of reaction of powdered marble and marble chips with hydrochloric acid
- Relate surface area effects to real-life examples such as why powdered medicines dissolve faster than tablets and why charcoal burns faster when broken into smaller pieces

In groups, learners are guided to:
- Carry out Hands-on Activity 8 using powdered marble and marble chips with hydrochloric acid
- Measure volume of gas produced every 30 seconds using a gas syringe
- Record results in Table 2.48 and draw a graph of volume of CO₂ against time
- Read the scenario on surface area effects and discuss with peers

How does increasing the surface area of a reactant speed up a chemical reaction, and where is this principle used in daily life?

- Humming Bird General Science pg. 231
- Marble chips and marble powder
- Dilute hydrochloric acid
- Gas syringe and conical flask
- Weighing balance
- Stopwatch
- Hydrogen peroxide solution
- Manganese(IV) oxide
- Boiling tubes and wooden splint
- Digital devices
- Reference books

- Oral questions - Observation - Written tests

Matter and Chemical Reactions

Rates of Reactions -Effect of light and pressure on reaction rate

By the end of the lesson, the learner should be able to:
- Explain how light intensity affects the rate of light-dependent reactions such as the reaction between silver nitrate and potassium bromide
- Explain how increasing pressure speeds up reactions involving gases
- Connect light and pressure effects to real-life applications such as photography, photosynthesis and industrial gas reactions in fertiliser and fuel production

In groups, learners are guided to:
- Carry out Hands-on Activity on the effect of light using silver nitrate and potassium bromide in test tubes placed in different light conditions
- Study Figure 2.59 on the effect of pressure on gas particles
- Discuss how pressure affects reaction rate using the high pressure and low pressure diagrams
- Write notes on the effects of light and pressure on reaction rates

How do light and pressure affect the rate of reactions, and how are these factors used in photography and industrial gas processes?

- Humming Bird General Science pg. 231
- Silver nitrate solution
- Potassium bromide solution
- Test tubes and a box
- Digital devices
- Reference books

- Oral questions - Observation - Written tests

Matter and Chemical Reactions
Natural Physical Science
Natural Physical Science
Natural Physical Science

Rates of Reactions -Importance of optimum conditions in biological, chemical and physical processes
Turning Effect of Force -Meaning of moment of force
Turning Effect of Force -Factors affecting turning effect
Turning Effect of Force -Calculating moment (M = F × d)

By the end of the lesson, the learner should be able to:
- Define optimum conditions and explain their importance in biological, chemical and physical processes
- Describe how optimum conditions maximise efficiency in industrial processes such as the Haber process and in biological processes such as enzyme activity
- Connect optimum conditions to everyday decisions such as setting the correct oven temperature for baking, maintaining body temperature for health and choosing the right conditions for fermenting yoghurt

In groups, learners are guided to:
- Research the importance of optimum conditions using digital devices
- Study Table 2.49 summarising optimum conditions for biological, chemical and physical processes
- Read and discuss the findings of Groups A, B and C from the factory field trip scenario
- Discuss other processes where optimising conditions is beneficial and share with peers

Why is controlling temperature, pressure and concentration so important for making chemical and biological processes safe and efficient?

- Humming Bird General Science pg. 231
- Digital devices
- Internet access
- Reference books
- Charts summarising optimum conditions
- Humming Bird General Science Learner's Book pg. 252
- Digital resources
- Spanners, lift pump, metre rule
- Humming Bird General Science Learner's Book pg. 254
- Calculator

- Oral questions - Observation - Written assignments

Natural Physical Science

Turning Effect of Force -Principle of moments
Turning Effect of Force -Calculations using principle of moments
Turning Effect of Force -Moments due to beam weight

By the end of the lesson, the learner should be able to:
- State the principle of moments
- Demonstrate the principle of moments by balancing a metre rule
- Relate the principle of moments to balancing systems such as seesaws and beams

In groups, learners are guided to:
- Suspend a metre rule at its centre and hang known masses on either side
- Adjust positions until the rule balances horizontally
- Measure distances and calculate clockwise and anticlockwise moments
- Discuss findings and state the principle of moments

How does a seesaw balance when people of different weights sit at different distances from the centre?

- Humming Bird General Science Learner's Book pg. 256
- Metre rule, string, known masses, stand
- Digital resources
- Calculator
- Reference books
- Humming Bird General Science Learner's Book pg. 258
- Metre rule, spring balance, stand

- Observation - Oral questions

Natural Physical Science

Turning Effect of Force -Antiparallel forces
Turning Effect of Force -Calculations on antiparallel forces
Turning Effect of Force -Real-life applications and importance

By the end of the lesson, the learner should be able to:
- Define antiparallel forces and describe how they act on an object
- Distinguish between a single force and a couple (antiparallel forces)
- Relate antiparallel forces to everyday examples such as turning a bicycle handlebar or steering wheel

In groups, learners are guided to:
- Watch animations or simulations on moments of antiparallel forces using a digital device
- Attach Newton balances at both ends of a wooden strip and compare force required to rotate the strip with one and two balances
- Discuss findings with peers

How does a driver use two hands on a steering wheel to turn it more effectively than using one hand?

- Humming Bird General Science Learner's Book pg. 260
- Wooden strip, Newton balances, screw
- Digital resources
- Humming Bird General Science Learner's Book pg. 261
- Calculator
- Reference books
- Humming Bird General Science Learner's Book pg. 263
- Internet access

- Observation - Oral questions

Natural Physical Science

Linear Motion -Distance and displacement
Linear Motion -Calculations on distance and displacement

By the end of the lesson, the learner should be able to:
- Define distance and displacement and state their SI units
- Distinguish between distance and displacement using practical examples
- Relate the difference between distance and displacement to navigation and everyday travel

In groups, learners are guided to:
- Mark points A, B and C in the field using pegs
- Measure the length AC through B (distance) and the straight line AC (displacement)
- Record and discuss the differences between the two measurements with peers

Why does a GPS device show a shorter distance to a destination than the actual road distance travelled?

- Humming Bird General Science Learner's Book pg. 269
- Tape measure, pegs, hammer
- Reference books
- Humming Bird General Science Learner's Book pg. 270
- Calculator

- Oral questions - Observation

Natural Physical Science

Linear Motion -Speed and velocity

By the end of the lesson, the learner should be able to:
- Define speed and velocity and state their SI units
- Distinguish between speed and velocity
- Relate the difference between speed and velocity to real-life motion such as cars on a straight road and roundabouts

In groups, learners are guided to:
- Study pictures of cars in motion and discuss the difference between speed and velocity
- Discuss with peers why velocity requires direction while speed does not
- Write brief notes on the differences between speed and velocity

Why does a car moving at a constant speed around a roundabout have a changing velocity?

- Humming Bird General Science Learner's Book pg. 272
- Digital resources
- Reference books

- Oral questions - Observation

Natural Physical Science

Linear Motion -Practical determination of velocity
Linear Motion -Calculations on speed and velocity

By the end of the lesson, the learner should be able to:
- Determine velocity practically by measuring distance and time
- Record and analyse motion data to calculate average velocity
- Relate practical velocity measurements to real-life scenarios such as timing athletes and vehicles

- Mark a measured distance in the field and time a learner walking or running across it
- Calculate velocity using v = distance ÷ time
- Repeat with different distances and compare results

How do traffic officers use speed guns to measure the velocity of vehicles on a highway?

- Humming Bird General Science Learner's Book pg. 272
- Tape measure, stopwatch, pegs
- Calculator
- Reference books

- Observation - Written assignments

Natural Physical Science

Linear Motion -Acceleration
Linear Motion -Calculations on acceleration and deceleration

By the end of the lesson, the learner should be able to:
- Define acceleration and deceleration and state their SI units
- Distinguish between acceleration and deceleration using practical examples
- Relate acceleration and deceleration to everyday situations such as vehicles speeding up or braking

In groups, learners are guided to:
- Discuss the meaning of acceleration as the rate of change of velocity
- Identify examples of acceleration and deceleration in daily life such as a bus pulling away from a stop and braking at a stage
- Write brief notes on acceleration and deceleration

How does a car manufacturer use acceleration values to describe the performance of a vehicle?

- Humming Bird General Science Learner's Book pg. 274
- Digital resources
- Reference books
- Calculator

- Oral questions - Observation

Natural Physical Science

Linear Motion -Equations of motion (v = u + at)
Linear Motion -Equations of motion (s = ut + ½at² and v² = u² + 2as)

By the end of the lesson, the learner should be able to:
- State and apply the equation v = u + at
- Identify the variables of motion: initial velocity, final velocity, acceleration and time
- Relate the first equation of motion to real-life situations such as a car accelerating from rest

In groups, learners are guided to:
- Introduce the five variables of motion using a table (u, v, a, s, t)
- Solve problems using v = u + at where three variables are known
- Work through examples involving vehicles, boulders and runners

How would you use v = u + at to find the speed of a matatu after accelerating for a given time from rest?

- Humming Bird General Science Learner's Book pg. 276
- Calculator
- Reference books

- Written assignments - Oral questions

Natural Physical Science

Linear Motion -Free fall and gravity

By the end of the lesson, the learner should be able to:
- Define free fall and explain the effect of gravity on falling bodies
- Describe how air resistance affects falling objects of different shapes
- Relate free fall to real-life situations such as falling objects on construction sites and skydiving

In groups, learners are guided to:
- Drop a stone and a flat paper simultaneously and observe which hits the ground first
- Repeat the experiment with the paper folded into a tight ball and compare results
- Discuss how air resistance affects the paper but not the stone and relate to vacuum conditions

Why do skydivers open parachutes to slow their fall rather than falling freely to the ground?

- Humming Bird General Science Learner's Book pg. 283
- Stone, paper, writing materials
- Digital resources

- Observation - Oral questions

Natural Physical Science

Linear Motion -Tick timer investigation
Linear Motion -Free fall calculations

By the end of the lesson, the learner should be able to:
- Describe how a tick timer is used to investigate motion
- Analyse ticker tape results to determine velocity and acceleration
- Relate ticker tape analysis to how speed cameras and data loggers record vehicle motion

In groups, learners are guided to:
- Set up a ramp using books and cardboard and release different objects such as a marble, toy car, apple and pumpkin
- Observe and record how speed increases from rest to maximum at the bottom
- Analyse speed-time data from a table and calculate acceleration due to gravity

How do engineers use motion sensors and data loggers to monitor the speed of vehicles during crash testing?

- Humming Bird General Science Learner's Book pg. 285
- Cardboard, books, toy car, marble, apple
- Stopwatch, ruler
- Humming Bird General Science Learner's Book pg. 287
- Calculator
- Reference books

- Observation - Written assignments

Natural Physical Science

Linear Motion -Safety on slopes
Linear Motion -Real-life applications of linear motion

By the end of the lesson, the learner should be able to:
- Explain the dangers of accelerating on steeply sloping roads
- Identify safety measures used to minimise injuries from free fall and steep slopes
- Relate knowledge of free fall and acceleration to road safety practices such as speed limits and guardrails on hills

In groups, learners are guided to:
- Study pictures showing dangers of accelerating on sloping surfaces
- Discuss dangers including brake failure, traction loss and vehicles toppling on tight corners
- Discuss safety measures including harnesses on construction sites, parachutes in skydiving and seat belts in aircraft

Why are trucks required to use low gears and engine braking when descending steep mountain roads?

- Humming Bird General Science Learner's Book pg. 288
- Digital resources
- Pictures of road accidents on slopes
- Humming Bird General Science Learner's Book pg. 281
- Internet access

- Oral questions - Observation

Natural Physical Science

Waves -Amplitude and wavelength

By the end of the lesson, the learner should be able to:
- Define amplitude and wavelength and state their SI units
- Identify amplitude and wavelength on diagrams of transverse and longitudinal waves
- Relate amplitude and wavelength to real-life examples such as sound loudness and radio signal range

In groups, learners are guided to:
- Study diagrams of transverse waves and identify crests, troughs, amplitude and wavelength
- Use print or non-print media to research on terms used in waves
- Draw and label wave diagrams showing amplitude and wavelength

How does increasing the amplitude of a sound wave affect how loud the sound appears to a listener?

- Humming Bird General Science Learner's Book pg. 314
- Digital resources
- Wave diagrams, rulers

- Oral questions - Observation

Natural Physical Science

Waves -Frequency and period
Waves -Velocity of waves

By the end of the lesson, the learner should be able to:
- Define frequency and period and state their SI units
- Relate frequency and period using the equation T = 1/f
- Relate frequency and period to real-life applications such as radio broadcasting frequencies and musical notes

In groups, learners are guided to:
- Study displacement-time graphs and identify the period of a wave
- Calculate frequency from period and vice versa using T = 1/f
- Discuss examples such as radio stations broadcasting at specific frequencies

Why do radio stations broadcast at specific frequencies and what would happen if two stations used the same frequency?

- Humming Bird General Science Learner's Book pg. 315
- Digital resources
- Wave diagrams, calculator
- Humming Bird General Science Learner's Book pg. 316
- Reference books

- Oral questions - Written assignments

Natural Physical Science

Waves -Wave equation
Waves -Calculations using wave equation

By the end of the lesson, the learner should be able to:
- State the wave equation v = fλ
- Explain the relationship between wave speed, frequency and wavelength
- Relate the wave equation to real-life applications such as radio wave transmission and sonar

In groups, learners are guided to:
- Stretch a long rope on a flat surface and oscillate it to create waves
- Measure wavelength by marking distance between successive crests
- Count waves passing a fixed point in 10 seconds to find frequency and use v = fλ to calculate wave speed

How do telecommunications engineers use the wave equation to determine the wavelength of signals transmitted by mobile phone towers?

- Humming Bird General Science Learner's Book pg. 317
- Long rope, stopwatch, ruler
- Digital resources
- Humming Bird General Science Learner's Book pg. 318
- Calculator
- Reference books

- Observation - Oral questions

Natural Physical Science

Waves -Reflection of sound and echo
Waves -Refraction of sound

By the end of the lesson, the learner should be able to:
- Define reflection of waves and explain how echoes are formed
- Calculate the speed of sound using the echo method
- Relate reflection of sound to real-life applications such as sonar, ultrasound scanning and echo-location in bats

In groups, learners are guided to:
- Stand at a known distance from a large hard wall, clap hands and measure the time for the echo to return
- Calculate speed of sound using speed = 2d/t
- Repeat the experiment several times and calculate average speed of sound in air

How do ships use sonar to detect underwater objects by reflecting sound waves off the seabed?

- Humming Bird General Science Learner's Book pg. 320
- Stopwatch, measuring tape, hard wall
- Calculator
- Humming Bird General Science Learner's Book pg. 322
- Digital devices with internet access
- Drawing materials

- Observation - Written assignments

Natural Physical Science

Waves -Diffraction of sound

By the end of the lesson, the learner should be able to:
- Define diffraction and explain how sound bends around obstacles and through openings
- Investigate how sound can be heard around a corner or through a slightly open door
- Relate diffraction to real-life situations such as hearing vehicles approaching around a blind corner

In groups, learners are guided to:
- Position a ringing phone behind a wall and check whether a listener on the other side can hear it
- Repeat with a slightly open door and note how sound spreads through the opening
- Discuss how diffraction allows sound to bend around edges and through gaps

How does diffraction of sound help a pedestrian hear an approaching vehicle before it comes into view around a corner?

- Humming Bird General Science Learner's Book pg. 323
- Phone, large wall, door
- Measuring tape

- Observation - Oral questions

Natural Physical Science

Waves -Effects of waves on the environment
Waves -Mitigation measures against effects of waves

By the end of the lesson, the learner should be able to:
- Explain how sound waves affect communities, marine ecosystems and infrastructure
- Describe the impact of noise pollution on human health, wildlife and buildings
- Relate the effects of waves on the environment to real-life issues such as factory noise, ship engines and bridge vibrations

In groups, learners are guided to:
- Study pictures of factories, traffic and ships and discuss their noise effects on communities and marine life
- Discuss how loud ship engines disrupt whale communication and how vibrations damage buildings
- Write short notes on the effects of sound waves on communities, marine ecosystems, infrastructure and operations

How do loud ship engines and underwater sonar systems used for navigation affect the communication and behaviour of whales?

- Humming Bird General Science Learner's Book pg. 325
- Digital resources
- Pictures of industrial and marine environments
- Humming Bird General Science Learner's Book pg. 327
- Internet access

- Oral questions - Observation

Natural Physical Science

Waves -Applications in road safety, refraction and diffraction
Magnetism and Electromagnetic Induction -Magnetisation methods

By the end of the lesson, the learner should be able to:
- Explain how reflection, refraction and diffraction of sound waves contribute to road safety
- Describe how emergency sirens use wave properties to warn road users
- Relate wave properties to road safety systems such as sirens, fog horns and sound-based warning devices

In groups, learners are guided to:
- Study diagrams showing how reflection, refraction and diffraction are applied in road safety
- Discuss how a motorcycle engine sound bends around a corner to warn pedestrians before the vehicle is visible
- Discuss how emergency sirens use reflection to be heard around obstacles and refraction to travel farther in cold weather

How does the diffraction of sound from a vehicle horn help a pedestrian at a blind junction react in time to avoid an accident?

- Humming Bird General Science Learner's Book pg. 331
- Digital resources
- Internet access
- Humming Bird General Science Learner's Book pg. 338
- Soft iron rod, copper wire, battery, bar magnet, hammer, iron filings

- Oral questions - Written assignments

Natural Physical Science

Magnetism and Electromagnetic Induction -Demagnetisation

By the end of the lesson, the learner should be able to:
- Describe the electrical, hammering and heating methods of demagnetising a magnet
- Explain how each method disrupts the alignment of magnetic domains
- Relate demagnetisation to real-life situations such as erasing hotel key cards and resetting magnetic strips

In groups, learners are guided to:
- Wrap insulated copper wire around a magnetised soft iron rod, connect to AC power and test with iron filings after removing
- Strike a magnetised soft iron rod repeatedly with a hammer and test with iron filings
- Heat a magnetised soft iron rod until red-hot, allow to cool and test with iron filings
- Compare results of all three methods

Why must a magnet be oriented in the east-west direction during demagnetisation and what would happen if it were left pointing north-south?

- Humming Bird General Science Learner's Book pg. 344
- Magnetised soft iron rod, AC power source, hammer, Bunsen burner, tongs, iron filings

- Observation - Oral questions

Natural Physical Science

Magnetism and Electromagnetic Induction -Magnetic field patterns
Magnetism and Electromagnetic Induction -Direction and strength of fields

By the end of the lesson, the learner should be able to:
- Describe magnetic field patterns around bar magnets, U-shaped magnets and horseshoe magnets
- Draw magnetic field lines showing direction from north to south pole and regions of attraction and repulsion
- Relate magnetic field patterns to real-life devices such as electric motors, MRI scanners and loudspeakers

In groups, learners are guided to:
- Place a bar magnet on a flat surface, cover with paper and sprinkle iron filings to reveal field pattern
- Use a small compass to trace field lines around the magnet marking direction of needle at each point
- Draw and compare field patterns around unlike poles (attraction) and like poles (repulsion)

How do the magnetic field patterns around a horseshoe magnet make it more effective for lifting metal objects than a straight bar magnet?

- Humming Bird General Science Learner's Book pg. 347
- Bar magnet, iron filings, white paper, small compass
- Drawing materials
- Humming Bird General Science Learner's Book pg. 348
- Bar magnet, compass, drawing materials
- Digital resources

- Observation - Oral questions

Natural Physical Science

Magnetism and Electromagnetic Induction -Induced EMF
Magnetism and Electromagnetic Induction -Practical demonstration

By the end of the lesson, the learner should be able to:
- Define induced electromotive force (EMF) in electromagnetism
- State Faraday's law of electromagnetic induction
- Relate induced EMF to real-life devices such as bicycle dynamos, generators and transformers

In groups, learners are guided to:
- Use online resources or textbooks to research the meaning of induced EMF and Faraday's law
- Discuss how a changing magnetic field produces an EMF in a conductor
- Predict how a magnet's motion into a coil would affect a connected galvanometer

How does a bicycle dynamo use Faraday's law of electromagnetic induction to light the bicycle's headlamp without using batteries?

- Humming Bird General Science Learner's Book pg. 351
- Digital resources
- Reference books
- Humming Bird General Science Learner's Book pg. 352
- U-shaped magnet, galvanometer, straight conductor, connecting wires

- Oral questions - Observation

Natural Physical Science

Magnetism and Electromagnetic Induction -Factors affecting induced EMF
Magnetism and Electromagnetic Induction -Applications of electromagnetic induction

By the end of the lesson, the learner should be able to:
- Identify and explain the factors that affect the magnitude of induced EMF
- Describe how magnetic field strength, speed of motion, number of coil turns, angle of motion and type of material affect induced EMF
- Relate factors affecting induced EMF to the design of power generators in hydroelectric and wind power stations

In groups, learners are guided to:
- Use digital devices or print media to research on factors affecting the magnitude of induced EMF
- Discuss a case scenario of a school hydropower generator with reduced output during dry seasons
- Identify which EMF factors could be adjusted to increase power output and discuss with peers

How would a hydroelectric power station engineer increase the electricity output of a generator during a dry season when water flow is reduced?

- Humming Bird General Science Learner's Book pg. 354
- Digital resources
- Reference books
- Humming Bird General Science Learner's Book pg. 355
- Internet access

- Oral questions - Written assignments

Natural Physical Science

Magnetism and Electromagnetic Induction -Electric bell project

By the end of the lesson, the learner should be able to:
- Design and assemble a simple electric bell using locally available materials
- Explain how the electromagnetic principle makes the bell ring when the circuit is closed
- Relate the electric bell to real-life applications of electromagnets such as doorbells, relays and alarm systems

In groups, learners are guided to:
- Assemble an electric bell using a buzzer, battery, copper wire, iron nail, paperclip switch and plastic box
- Connect the circuit so that closing the switch causes the electromagnet to attract the hammer and strike the bell
- Test and troubleshoot the bell and present the working model to the class

How does the automatic reset mechanism in an electric doorbell use the principle of electromagnetic induction to repeatedly ring without being pressed again?

- Humming Bird General Science Learner's Book pg. 358
- Buzzer, battery, copper wire, iron nail, paperclip, plastic box, insulated wire, glue, tape

- Observation - Model making