Grade 7 Integrated Science — Term 1 Notes

<h1 class="notes-h1">GRADE 7 INTEGRATED SCIENCE — TERM 1 NOTES</h1>
<h2 class="notes-h2">CBC Aligned | Junior Secondary School</h2>
<h3 class="notes-h3">Learning Area: Integrated Science | Grade: 7 | Term: 1 | Year: 2026</h3>
<hr class="section-divider">
<p>*These notes cover all strands and sub-strands for Grade 7 Integrated Science, Term 1, aligned to the KICD Curriculum Design for Integrated Science (Junior Secondary). Practical activities use materials available in Kenyan schools.*</p>
<hr class="section-divider">
<h2 class="notes-h2">STRAND 1: SCIENTIFIC INVESTIGATION</h2>
<h3 class="notes-h3">Sub-Strand 1.1: Introduction to Scientific Investigation</h3>
<p><strong>Specific Learning Outcomes</strong></p>
<p>By the end of this sub-strand, the learner should be able to:</p>
<ul class="notes-list">
<li>Describe the steps of the scientific method</li>
<li>Formulate a testable hypothesis given a problem</li>
<li>Identify variables in a simple experiment (independent, dependent, controlled)</li>
<li>Record observations and data accurately</li>
<li>Draw conclusions from experimental results</li>
</ul>
<p><strong>Key Concepts</strong></p>
<p><strong>What is Science?</strong></p>
<p>Science is the systematic study of the natural world through observation and experimentation. <em>Integrated Science</em> brings together Biology, Chemistry, and Physics to help us understand how the world works.</p>
<p><strong>The Scientific Method</strong></p>
<p>The scientific method is a series of steps scientists follow to answer questions about the natural world.</p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Step</th><th>What you do</th><th>Example</th></tr>
</thead><tbody>
<tr><td><strong>1. Observation</strong></td><td>Notice something interesting</td><td><em>"Plants near the window grow taller."</em></td></tr>
<tr><td><strong>2. Question</strong></td><td>Ask a testable question</td><td><em>"Does amount of light affect plant growth?"</em></td></tr>
<tr><td><strong>3. Hypothesis</strong></td><td>Make an educated prediction</td><td><em>"More light causes faster plant growth."</em></td></tr>
<tr><td><strong>4. Experiment</strong></td><td>Design and carry out a test</td><td><em>Grow 3 plants in different light levels</em></td></tr>
<tr><td><strong>5. Data collection</strong></td><td>Record measurements/observations</td><td><em>Measure height daily for 2 weeks</em></td></tr>
<tr><td><strong>6. Analysis</strong></td><td>Look for patterns in your data</td><td><em>Plant A (most light) grew tallest</em></td></tr>
<tr><td><strong>7. Conclusion</strong></td><td>State whether hypothesis was correct</td><td><em>Hypothesis supported: light increases growth</em></td></tr>
<tr><td><strong>8. Communication</strong></td><td>Share findings</td><td><em>Write report, present to class</em></td></tr>
</tbody></table></div>
<p><strong>Writing a Hypothesis</strong></p>
<p>A hypothesis is a specific, testable prediction. Write it as an <strong>If...then</strong> statement:</p>
<blockquote class="notes-quote"><p><strong>Format:</strong> <em>"If [independent variable] is [changed], then [dependent variable] will [expected result], because [reasoning]."</em></p></blockquote>
<blockquote class="notes-quote"><p><strong>Example:</strong> <em>"If the amount of water given to bean plants is increased, then the plants will grow taller, because water is needed for photosynthesis and cell growth."</em></p></blockquote>
<p><strong>Variables in an Experiment</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Variable</th><th>Definition</th><th>Example (Plant Experiment)</th></tr>
</thead><tbody>
<tr><td><strong>Independent variable</strong></td><td>What the scientist changes</td><td>Amount of sunlight</td></tr>
<tr><td><strong>Dependent variable</strong></td><td>What the scientist measures</td><td>Height of plant</td></tr>
<tr><td><strong>Controlled variables</strong></td><td>Everything kept the same</td><td>Type of soil, amount of water, pot size, plant species</td></tr>
</tbody></table></div>
<p><em>Note: A fair test keeps all variables constant except the one being tested.</em></p>
<p><strong>Safety in the Laboratory</strong></p>
<p>Essential laboratory rules:</p>
<ol class="notes-list">
<li>Never eat or drink in the laboratory</li>
<li>Always wear protective equipment (goggles, gloves, apron) when required</li>
<li>Tie back long hair and loose clothing</li>
<li>Handle glassware with care</li>
<li>Report any breakages or spills immediately</li>
<li>Never point a test tube at yourself or others when heating</li>
<li>Wash hands thoroughly after experiments</li>
<li>Know the location of the fire extinguisher and first aid kit</li>
</ol>
<p><strong>Laboratory Equipment</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Equipment</th><th>Use</th></tr>
</thead><tbody>
<tr><td><strong>Beaker</strong></td><td>Holding and measuring liquids (approximate)</td></tr>
<tr><td><strong>Measuring cylinder</strong></td><td>Measuring volume of liquids accurately</td></tr>
<tr><td><strong>Test tube</strong></td><td>Holding small amounts of liquids for experiments</td></tr>
<tr><td><strong>Bunsen burner / spirit lamp</strong></td><td>Heating substances</td></tr>
<tr><td><strong>Thermometer</strong></td><td>Measuring temperature</td></tr>
<tr><td><strong>Hand lens / magnifying glass</strong></td><td>Enlarging small objects for observation</td></tr>
<tr><td><strong>Microscope</strong></td><td>Viewing very small objects (cells)</td></tr>
<tr><td><strong>Balance/spring balance</strong></td><td>Measuring mass/weight</td></tr>
<tr><td><strong>Stopwatch</strong></td><td>Measuring time</td></tr>
<tr><td><strong>Forceps/tweezers</strong></td><td>Handling small objects</td></tr>
</tbody></table></div>
<p><strong>Recording Data</strong></p>
<p>Always record data in a table with:</p>
<ul class="notes-list">
<li>Clear column headings</li>
<li>Units in the headings (not in each row)</li>
<li>Neat, accurate numbers</li>
</ul>
<p><em>Sample data table:</em></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Day</th><th>Plant A Height (cm)</th><th>Plant B Height (cm)</th><th>Plant C Height (cm)</th></tr>
</thead><tbody>
<tr><td>1</td><td>2.0</td><td>2.0</td><td>2.0</td></tr>
<tr><td>5</td><td>4.5</td><td>3.8</td><td>3.1</td></tr>
<tr><td>10</td><td>8.3</td><td>6.7</td><td>5.2</td></tr>
</tbody></table></div>
<p><strong>Review Questions</strong></p>
<ol class="notes-list">
<li>List the 8 steps of the scientific method in order.</li>
<li>Write a hypothesis for this question: <em>"Does the type of soil affect how quickly water drains?"</em></li>
<li>In an experiment testing how temperature affects the speed of sugar dissolving in water, identify: (a) the independent variable, (b) the dependent variable, (c) two controlled variables.</li>
<li>Why is it important to change only one variable in an experiment?</li>
</ol>
<hr class="section-divider">
<h3 class="notes-h3">Sub-Strand 1.2: Measurement in Science</h3>
<p><strong>Specific Learning Outcomes</strong></p>
<p>By the end of this sub-strand, the learner should be able to:</p>
<ul class="notes-list">
<li>Use SI units to measure length, mass, volume, temperature, and time</li>
<li>Record measurements with appropriate precision</li>
<li>Calculate area and volume of regular shapes</li>
<li>Convert between common SI units</li>
</ul>
<p><strong>Key Concepts</strong></p>
<p><strong>The SI System (Système International)</strong></p>
<p>Scientists worldwide use the same system of units — the SI system.</p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Quantity</th><th>SI Unit</th><th>Symbol</th></tr>
</thead><tbody>
<tr><td>Length</td><td>metre</td><td>m</td></tr>
<tr><td>Mass</td><td>kilogram</td><td>kg</td></tr>
<tr><td>Volume</td><td>litre (or cubic metre)</td><td>L or m³</td></tr>
<tr><td>Temperature</td><td>Kelvin (science) / Celsius (everyday)</td><td>K / °C</td></tr>
<tr><td>Time</td><td>second</td><td>s</td></tr>
</tbody></table></div>
<p><strong>Unit Conversions</strong></p>
<p><em>Length:</em></p>
<ul class="notes-list">
<li>1 km = 1,000 m</li>
<li>1 m = 100 cm</li>
<li>1 cm = 10 mm</li>
</ul>
<p><em>Mass:</em></p>
<ul class="notes-list">
<li>1 kg = 1,000 g</li>
<li>1 g = 1,000 mg</li>
</ul>
<p><em>Volume:</em></p>
<ul class="notes-list">
<li>1 L = 1,000 mL</li>
<li>1 mL = 1 cm³</li>
</ul>
<p><strong>Measuring Length</strong></p>
<p>Use a ruler or metre stick. Read from the <strong>0 mark</strong> (not the edge of the ruler).</p>
<p><em>Practise:</em> Measure the length and width of your exercise book. Calculate its area.</p>
<p><strong>Area and Volume Formulae</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Shape</th><th>Formula</th></tr>
</thead><tbody>
<tr><td>Rectangle/square area</td><td>length × width</td></tr>
<tr><td>Triangle area</td><td>½ × base × height</td></tr>
<tr><td>Circle area</td><td>π × radius² (π ≈ 3.14)</td></tr>
<tr><td>Rectangular block volume</td><td>length × width × height</td></tr>
</tbody></table></div>
<p><em>Example:</em> A garden plot is 4 m long and 2.5 m wide. Its area = 4 × 2.5 = <strong>10 m²</strong></p>
<p><strong>Measuring Volume of Liquids</strong></p>
<p>Use a measuring cylinder. Read the level at the <strong>bottom of the meniscus</strong> (curved surface).</p>
<p><strong>Measuring Volume of Irregular Solids</strong></p>
<p>Use the <em>water displacement method</em>:</p>
<ol class="notes-list">
<li>Fill measuring cylinder to a known volume (e.g., 50 mL)</li>
<li>Carefully place the solid in the water</li>
<li>Record the new volume</li>
<li>Volume of solid = new volume − original volume</li>
</ol>
<p><em>Example:</em> Water level rises from 50 mL to 67 mL when a stone is added.</p>
<p>Volume of stone = 67 − 50 = <strong>17 mL = 17 cm³</strong></p>
<p><strong>Review Questions</strong></p>
<ol class="notes-list">
<li>Convert: (a) 3.5 km to metres (b) 250 g to kilograms (c) 0.75 L to millilitres</li>
<li>A box is 30 cm long, 20 cm wide, and 15 cm high. What is its volume in cm³?</li>
<li>A student places a rock in a measuring cylinder. The water level rises from 40 mL to 58 mL. What is the volume of the rock?</li>
<li>Draw a simple diagram of a measuring cylinder and show where to read the volume.</li>
</ol>
<hr class="section-divider">
<h2 class="notes-h2">STRAND 2: LIVING THINGS AND THEIR ENVIRONMENT</h2>
<h3 class="notes-h3">Sub-Strand 2.1: The Cell — Basic Unit of Life</h3>
<p><strong>Specific Learning Outcomes</strong></p>
<p>By the end of this sub-strand, the learner should be able to:</p>
<ul class="notes-list">
<li>State that the cell is the basic unit of life</li>
<li>Describe the structure and function of the cell membrane, cytoplasm, nucleus, and mitochondria</li>
<li>Compare plant cells and animal cells</li>
<li>Identify cells under a microscope or in a diagram</li>
</ul>
<p><strong>Key Concepts</strong></p>
<p><strong>What is a Cell?</strong></p>
<p>A cell is the smallest unit of life. All living things are made of cells. Some organisms (bacteria) are made of just one cell (unicellular). Others, like humans and trees, are made of millions of cells (multicellular).</p>
<p><em>Who discovered cells?</em> Robert Hooke (1665) — observed cork cells through a simple microscope. He called them "cells" because they looked like small rooms.</p>
<p><strong>Parts of a Cell and Their Functions</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Part</th><th>Found in</th><th>Function</th></tr>
</thead><tbody>
<tr><td><strong>Cell membrane</strong></td><td>Animal + Plant</td><td>Controls what enters and leaves the cell</td></tr>
<tr><td><strong>Cytoplasm</strong></td><td>Animal + Plant</td><td>Jelly-like fluid; where chemical reactions occur</td></tr>
<tr><td><strong>Nucleus</strong></td><td>Animal + Plant</td><td>Controls cell activities; contains DNA (genetic material)</td></tr>
<tr><td><strong>Mitochondria</strong></td><td>Animal + Plant</td><td>Site of respiration — releases energy for the cell</td></tr>
<tr><td><strong>Ribosomes</strong></td><td>Animal + Plant</td><td>Make proteins</td></tr>
<tr><td><strong>Cell wall</strong></td><td>Plant only</td><td>Made of cellulose; provides shape and support</td></tr>
<tr><td><strong>Chloroplast</strong></td><td>Plant only</td><td>Contains chlorophyll; site of photosynthesis</td></tr>
<tr><td><strong>Vacuole</strong></td><td>Plant (large) / Animal (small)</td><td>Stores water, sap, and nutrients</td></tr>
</tbody></table></div>
<p><strong>Animal Cell vs Plant Cell</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Feature</th><th>Animal Cell</th><th>Plant Cell</th></tr>
</thead><tbody>
<tr><td>Cell wall</td><td>✗ Absent</td><td>✓ Present (cellulose)</td></tr>
<tr><td>Chloroplasts</td><td>✗ Absent</td><td>✓ Present (in green parts)</td></tr>
<tr><td>Vacuole</td><td>Small or absent</td><td>Large central vacuole</td></tr>
<tr><td>Shape</td><td>Irregular</td><td>Regular, fixed shape</td></tr>
<tr><td>Energy source</td><td>Food (glucose from eating)</td><td>Makes own food (photosynthesis)</td></tr>
</tbody></table></div>
<p><strong>Drawing Cells</strong></p>
<p>When drawing cells:</p>
<ul class="notes-list">
<li>Draw with a pencil</li>
<li>Make the diagram large (at least ½ page)</li>
<li>Label clearly with ruled lines</li>
<li>Do not shade — use neat outlines</li>
<li>Write the title and state the magnification</li>
</ul>
<p><strong>Levels of Organisation in Living Things</strong></p>
<pre class="code-block"><code>
Cell → Tissue → Organ → Organ System → Organism
</code></pre>
<p><em>Example (human):</em></p>
<p>Muscle cell → Muscle tissue → Heart (organ) → Circulatory system → Human body</p>
<p><strong>Review Questions</strong></p>
<ol class="notes-list">
<li>State the function of each: (a) nucleus (b) cell membrane (c) chloroplast (d) mitochondria</li>
<li>Give <strong>three</strong> differences between a plant cell and an animal cell.</li>
<li>Draw and label a plant cell. Include at least 6 labelled parts.</li>
<li>Arrange in order from smallest to largest: <em>organ, organism, tissue, cell, organ system.</em></li>
</ol>
<hr class="section-divider">
<h3 class="notes-h3">Sub-Strand 2.2: Classification of Living Things</h3>
<p><strong>Specific Learning Outcomes</strong></p>
<p>By the end of this sub-strand, the learner should be able to:</p>
<ul class="notes-list">
<li>Explain the need for classifying living things</li>
<li>Identify the five kingdoms of living things</li>
<li>Classify animals as vertebrates or invertebrates</li>
<li>Identify examples of organisms in each major group</li>
</ul>
<p><strong>Key Concepts</strong></p>
<p><strong>Why Do We Classify Living Things?</strong></p>
<p>Classification (taxonomy) helps us:</p>
<ol class="notes-list">
<li>Identify and name organisms accurately</li>
<li>Study relationships between organisms</li>
<li>Organise knowledge about the huge variety of life</li>
<li>Predict characteristics of unknown organisms based on their group</li>
</ol>
<p><strong>The Five Kingdoms</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Kingdom</th><th>Characteristics</th><th>Examples</th></tr>
</thead><tbody>
<tr><td><strong>Monera</strong></td><td>Single-celled, no true nucleus</td><td>Bacteria, blue-green algae</td></tr>
<tr><td><strong>Protista</strong></td><td>Mostly single-celled, have nucleus</td><td>Amoeba, Paramecium, algae</td></tr>
<tr><td><strong>Fungi</strong></td><td>Cannot make own food; absorb nutrients</td><td>Mushrooms, moulds, yeast</td></tr>
<tr><td><strong>Plantae</strong></td><td>Make own food (photosynthesis); cell wall</td><td>Trees, grasses, ferns, mosses</td></tr>
<tr><td><strong>Animalia</strong></td><td>Cannot make own food; no cell wall</td><td>Fish, birds, insects, humans</td></tr>
</tbody></table></div>
<p><strong>The Animal Kingdom: Vertebrates and Invertebrates</strong></p>
<p><strong>Vertebrates</strong> (have a backbone):</p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Group</th><th>Key Features</th><th>Kenyan Examples</th></tr>
</thead><tbody>
<tr><td><strong>Fish</strong></td><td>Gills, scales, fins, cold-blooded</td><td>Nile perch, tilapia</td></tr>
<tr><td><strong>Amphibians</strong></td><td>Live in water AND land, moist skin, cold-blooded</td><td>Frogs, toads, salamanders</td></tr>
<tr><td><strong>Reptiles</strong></td><td>Dry scaly skin, cold-blooded, lay eggs on land</td><td>Chameleons, geckos, crocodiles</td></tr>
<tr><td><strong>Birds</strong></td><td>Feathers, wings, warm-blooded, lay eggs</td><td>African fish eagle, flamingo, ostrich</td></tr>
<tr><td><strong>Mammals</strong></td><td>Hair/fur, warm-blooded, give birth to live young, produce milk</td><td>Lion, elephant, giraffe, humans</td></tr>
</tbody></table></div>
<p><strong>Invertebrates</strong> (no backbone) — make up about 97% of all animal species:</p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Group</th><th>Key Features</th><th>Examples</th></tr>
</thead><tbody>
<tr><td><strong>Insects</strong></td><td>3 body parts, 6 legs, 3 pairs of legs</td><td>Mosquito, butterfly, bee, locust</td></tr>
<tr><td><strong>Arachnids</strong></td><td>2 body parts, 8 legs</td><td>Spider, scorpion, tick</td></tr>
<tr><td><strong>Crustaceans</strong></td><td>Hard shell, many legs, mostly aquatic</td><td>Crab, shrimp, crayfish</td></tr>
<tr><td><strong>Worms</strong></td><td>Soft, long body; no legs</td><td>Earthworm, tapeworm</td></tr>
<tr><td><strong>Molluscs</strong></td><td>Soft body, often with shell</td><td>Snail, octopus, clam</td></tr>
</tbody></table></div>
<p><strong>Classification Key (Dichotomous Key)</strong></p>
<p>A dichotomous key helps identify an organism by answering YES/NO questions:</p>
<pre class="code-block"><code>
1a. Does it have legs? → Go to 2
1b. Does it have no legs? → Worm/Snake

2a. Does it have 6 legs? → Insect
2b. Does it have 8 legs? → Arachnid
2c. Does it have more than 8 legs? → Crustacean/Myriapod
</code></pre>
<p><strong>Review Questions</strong></p>
<ol class="notes-list">
<li>Name the five kingdoms and give one example from each found in Kenya.</li>
<li>What is the main difference between a vertebrate and an invertebrate?</li>
<li>A scientist finds an animal with dry, scaly skin that lays eggs on land. Which vertebrate group does it belong to?</li>
<li>Give <strong>two</strong> features that distinguish birds from all other vertebrate groups.</li>
<li>Use the simple dichotomous key above to classify: (a) a bee (b) an earthworm (c) a scorpion</li>
</ol>
<hr class="section-divider">
<h2 class="notes-h2">STRAND 3: MATTER AND ITS PROPERTIES</h2>
<h3 class="notes-h3">Sub-Strand 3.1: States of Matter</h3>
<p><strong>Specific Learning Outcomes</strong></p>
<p>By the end of this sub-strand, the learner should be able to:</p>
<ul class="notes-list">
<li>Identify and describe the three states of matter</li>
<li>Explain the properties of solids, liquids, and gases in terms of particle arrangement</li>
<li>Describe changes of state (melting, freezing, evaporation, condensation, sublimation)</li>
<li>Relate changes of state to energy changes (heating and cooling)</li>
</ul>
<p><strong>Key Concepts</strong></p>
<p><strong>The Three States of Matter</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Property</th><th>Solid</th><th>Liquid</th><th>Gas</th></tr>
</thead><tbody>
<tr><td><strong>Shape</strong></td><td>Definite shape</td><td>Takes shape of container</td><td>No definite shape</td></tr>
<tr><td><strong>Volume</strong></td><td>Definite volume</td><td>Definite volume</td><td>Fills container</td></tr>
<tr><td><strong>Particles</strong></td><td>Tightly packed, vibrate in place</td><td>Close together, can flow</td><td>Far apart, move freely</td></tr>
<tr><td><strong>Compressibility</strong></td><td>Cannot be compressed</td><td>Very slightly</td><td>Highly compressible</td></tr>
<tr><td><strong>Examples</strong></td><td>Iron, ice, salt</td><td>Water, milk, oil</td><td>Air, steam, oxygen</td></tr>
</tbody></table></div>
<p><strong>Particle Theory of Matter</strong></p>
<p>All matter is made of tiny particles (atoms, molecules) that:</p>
<ul class="notes-list">
<li>Are always in motion</li>
<li>Have spaces between them</li>
<li>Attract each other</li>
<li>Move faster when heated</li>
</ul>
<p><em>Why do solids keep their shape?</em> Particles are packed tightly with strong attractive forces.</p>
<p><em>Why do gases spread out?</em> Particles have little attraction and move very fast.</p>
<p><strong>Changes of State</strong></p>
<pre class="code-block"><code>
MELTING EVAPORATION/BOILING
SOLID ────────────► LIQUID ────────────────────────► GAS
◄──────────── ◄────────────────────────
FREEZING CONDENSATION

SOLID ──────────────────────────────────────────► GAS
◄──────────────────────────────────────────
SUBLIMATION
</code></pre>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Change</th><th>State changes from → to</th><th>Energy</th><th>Example</th></tr>
</thead><tbody>
<tr><td><strong>Melting</strong></td><td>Solid → Liquid</td><td>Absorbed</td><td>Ice melting in Kenya's heat</td></tr>
<tr><td><strong>Freezing</strong></td><td>Liquid → Solid</td><td>Released</td><td>Water freezing in Mt Kenya glaciers</td></tr>
<tr><td><strong>Evaporation</strong></td><td>Liquid → Gas</td><td>Absorbed</td><td>Puddles drying after rain</td></tr>
<tr><td><strong>Condensation</strong></td><td>Gas → Liquid</td><td>Released</td><td>Dew on grass in the morning</td></tr>
<tr><td><strong>Boiling</strong></td><td>Liquid → Gas (bulk)</td><td>Absorbed</td><td>Water boiling for ugali</td></tr>
<tr><td><strong>Sublimation</strong></td><td>Solid → Gas (no liquid)</td><td>Absorbed</td><td>Dry ice "smoking"</td></tr>
</tbody></table></div>
<p><strong>Melting Point and Boiling Point</strong></p>
<ul class="notes-list">
<li><strong>Melting point:</strong> Temperature at which a solid becomes a liquid</li>
<li>Water: 0°C</li>
<li><strong>Boiling point:</strong> Temperature at which a liquid becomes a gas</li>
<li>Water: 100°C (at sea level; lower at altitude — e.g., on Mt Kenya water boils below 100°C)</li>
<li>Pure substances have fixed melting and boiling points — useful for identification</li>
</ul>
<p><strong>Practical Activity: Observing Changes of State</strong></p>
<p><em>Materials:</em> Ice cubes, a beaker, a Bunsen burner or heat source, thermometer</p>
<p><em>Procedure:</em></p>
<ol class="notes-list">
<li>Place ice cubes in a beaker</li>
<li>Note the temperature (should be 0°C or below)</li>
<li>Gently heat the ice</li>
<li>Record temperature every minute</li>
<li>Continue heating until water boils</li>
</ol>
<p><em>Expected results:</em></p>
<ul class="notes-list">
<li>Temperature stays at 0°C while ice melts (energy going to change state, not raise temperature)</li>
<li>Temperature rises from 0°C to 100°C as liquid water heats</li>
<li>Temperature stays at 100°C while water boils</li>
</ul>
<p><strong>Review Questions</strong></p>
<ol class="notes-list">
<li>Describe the arrangement of particles in (a) a solid (b) a gas.</li>
<li>What change of state occurs when: (a) rain falls on warm ground and disappears (b) morning dew forms on leaves (c) a candle wax melts?</li>
<li>Water is heated from −10°C until it becomes steam. Describe what happens at each stage.</li>
<li>Why does water boil at a lower temperature at high altitude places like Naivasha compared to Mombasa?</li>
</ol>
<hr class="section-divider">
<h3 class="notes-h3">Sub-Strand 3.2: Mixtures and Pure Substances</h3>
<p><strong>Specific Learning Outcomes</strong></p>
<p>By the end of this sub-strand, the learner should be able to:</p>
<ul class="notes-list">
<li>Distinguish between pure substances and mixtures</li>
<li>Classify mixtures as homogeneous or heterogeneous</li>
<li>Describe methods of separating mixtures (filtration, evaporation, distillation, chromatography, decanting, sieving)</li>
<li>Explain the principle behind each separation method</li>
</ul>
<p><strong>Key Concepts</strong></p>
<p><strong>Pure Substances vs Mixtures</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th></th><th>Pure Substance</th><th>Mixture</th></tr>
</thead><tbody>
<tr><td><strong>Composition</strong></td><td>One type of material only</td><td>Two or more substances combined</td></tr>
<tr><td><strong>Properties</strong></td><td>Fixed melting/boiling point</td><td>Varies depending on proportions</td></tr>
<tr><td><strong>Can be separated?</strong></td><td>No (by physical methods)</td><td>Yes (physical methods)</td></tr>
<tr><td><strong>Examples</strong></td><td>Pure water, pure gold, oxygen gas</td><td>Salt water, air, soil, blood</td></tr>
</tbody></table></div>
<p><strong>Types of Mixtures</strong></p>
<ul class="notes-list">
<li><strong>Homogeneous mixture (solution):</strong> Uniform throughout — you cannot see different parts</li>
</ul>
<blockquote class="notes-quote"><p>Salt dissolved in water, sugar in tea, air</p></blockquote>
<ul class="notes-list">
<li><strong>Heterogeneous mixture:</strong> Non-uniform — you can see different parts</li>
</ul>
<blockquote class="notes-quote"><p>Sand and water, oil and water, salad, soil</p></blockquote>
<p><strong>Key Terms</strong></p>
<ul class="notes-list">
<li><strong>Solute:</strong> The substance being dissolved (e.g., salt)</li>
<li><strong>Solvent:</strong> The substance doing the dissolving (e.g., water)</li>
<li><strong>Solution:</strong> Solute dissolved in solvent</li>
<li><strong>Soluble:</strong> Dissolves in the solvent</li>
<li><strong>Insoluble:</strong> Does not dissolve</li>
</ul>
<p><strong>Separation Methods</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Method</th><th>How it works</th><th>Used when...</th></tr>
</thead><tbody>
<tr><td><strong>Sieving</strong></td><td>Different particle sizes pass through mesh</td><td>Separating large solids from smaller ones (e.g., stones from soil)</td></tr>
<tr><td><strong>Filtration</strong></td><td>Filter paper traps insoluble solid; liquid passes through</td><td>Separating insoluble solid from liquid (e.g., sand from water)</td></tr>
<tr><td><strong>Evaporation</strong></td><td>Liquid heated away, solid remains</td><td>Recovering dissolved solid from solution (e.g., getting salt from salt water)</td></tr>
<tr><td><strong>Distillation</strong></td><td>Liquid boiled off, cooled, collected</td><td>Separating liquids with different boiling points; purifying water</td></tr>
<tr><td><strong>Decanting</strong></td><td>Pouring off liquid carefully, leaving dense solid</td><td>Separating solid that settles from liquid (e.g., muddy water)</td></tr>
<tr><td><strong>Magnetic separation</strong></td><td>Magnet attracts magnetic materials</td><td>Separating iron filings from sand</td></tr>
<tr><td><strong>Chromatography</strong></td><td>Substances travel at different rates in a solvent</td><td>Separating coloured substances (e.g., inks, dyes)</td></tr>
</tbody></table></div>
<p><strong>Simple Filtration Experiment</strong></p>
<p><em>Aim:</em> Separate sand from water</p>
<p><em>Materials:</em> Beaker, funnel, filter paper, sand-water mixture, stand and clamp</p>
<p><em>Procedure:</em></p>
<ol class="notes-list">
<li>Fold filter paper into a cone and place in funnel</li>
<li>Set funnel over a clean beaker</li>
<li>Pour sand-water mixture slowly through the filter paper</li>
<li>Observe: water (filtrate) passes through; sand (residue) remains on paper</li>
</ol>
<p><em>Observations and Results:</em></p>
<ul class="notes-list">
<li>The filtrate (water that passes through) is clear</li>
<li>The residue (sand) remains on the filter paper</li>
</ul>
<p><strong>Review Questions</strong></p>
<ol class="notes-list">
<li>Give an example of (a) a homogeneous mixture and (b) a heterogeneous mixture found in the kitchen.</li>
<li>Salt has been dissolved in water. Which separation method would you use to recover the salt? Explain the steps.</li>
<li>Why is filtration NOT suitable for separating salt from salt water?</li>
<li>A mixture contains iron filings, sand, and salt. Describe how you would completely separate all three components.</li>
</ol>
<hr class="section-divider">
<h2 class="notes-h2">STRAND 4: ENERGY AND ITS TRANSFORMATIONS</h2>
<h3 class="notes-h3">Sub-Strand 4.1: Forms of Energy</h3>
<p><strong>Specific Learning Outcomes</strong></p>
<p>By the end of this sub-strand, the learner should be able to:</p>
<ul class="notes-list">
<li>Identify and describe different forms of energy</li>
<li>Give examples of energy transformations (conversions) in everyday life</li>
<li>State the Law of Conservation of Energy</li>
<li>Identify renewable and non-renewable energy sources</li>
</ul>
<p><strong>Key Concepts</strong></p>
<p><strong>Forms of Energy</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Form</th><th>Description</th><th>Kenyan Examples</th></tr>
</thead><tbody>
<tr><td><strong>Kinetic energy</strong></td><td>Energy of moving objects</td><td>A matatu speeding, running water in a river</td></tr>
<tr><td><strong>Potential energy</strong></td><td>Stored energy (position or chemical)</td><td>A ball held high, food, petrol</td></tr>
<tr><td><strong>Heat (thermal) energy</strong></td><td>Energy from temperature</td><td>Fire, geothermal wells in Olkaria</td></tr>
<tr><td><strong>Light energy</strong></td><td>Energy from electromagnetic waves</td><td>Sunlight, electric bulbs</td></tr>
<tr><td><strong>Sound energy</strong></td><td>Energy from vibrations</td><td>Music, thunder, voices</td></tr>
<tr><td><strong>Electrical energy</strong></td><td>Energy from moving electrons</td><td>KPLC power, phone battery</td></tr>
<tr><td><strong>Chemical energy</strong></td><td>Energy stored in chemical bonds</td><td>Food, firewood, charcoal, batteries</td></tr>
<tr><td><strong>Nuclear energy</strong></td><td>Energy in atomic nuclei</td><td>Nuclear power plants (not in Kenya currently)</td></tr>
</tbody></table></div>
<p><strong>Energy Transformations</strong></p>
<p>Energy can change from one form to another. It is <strong>never created or destroyed</strong> — only converted.</p>
<p><em>This is the Law of Conservation of Energy:</em></p>
<blockquote class="notes-quote"><p><strong>"Energy cannot be created or destroyed; it can only be transformed from one form to another."</strong></p></blockquote>
<p><em>Common energy transformations:</em></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Device/Event</th><th>Energy In</th><th>Energy Out</th></tr>
</thead><tbody>
<tr><td>Solar panel</td><td>Light</td><td>Electrical</td></tr>
<tr><td>Electric bulb</td><td>Electrical</td><td>Light + Heat</td></tr>
<tr><td>Radio</td><td>Electrical</td><td>Sound + Heat</td></tr>
<tr><td>Burning charcoal</td><td>Chemical</td><td>Heat + Light</td></tr>
<tr><td>Car engine</td><td>Chemical (petrol)</td><td>Kinetic + Heat + Sound</td></tr>
<tr><td>Hydroelectric dam</td><td>Potential (water)</td><td>Electrical</td></tr>
<tr><td>Human body (eating)</td><td>Chemical (food)</td><td>Kinetic + Heat</td></tr>
<tr><td>Photosynthesis</td><td>Light</td><td>Chemical (glucose)</td></tr>
</tbody></table></div>
<p><strong>Kenya's Energy Sources</strong></p>
<p>Kenya is a leader in renewable energy in Africa.</p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Energy Source</th><th>Type</th><th>% of Kenya's Electricity (approx.)</th></tr>
</thead><tbody>
<tr><td>Geothermal (Olkaria)</td><td>Renewable</td><td>~44%</td></tr>
<tr><td>Hydroelectric (Tana River)</td><td>Renewable</td><td>~22%</td></tr>
<tr><td>Wind (Lake Turkana Wind Power)</td><td>Renewable</td><td>~15%</td></tr>
<tr><td>Solar</td><td>Renewable</td><td>Growing rapidly</td></tr>
<tr><td>Thermal (diesel/oil)</td><td>Non-renewable</td><td>~14%</td></tr>
</tbody></table></div>
<p><strong>Renewable vs Non-Renewable Energy</strong></p>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Renewable</th><th>Non-Renewable</th></tr>
</thead><tbody>
<tr><td>Can be replenished naturally</td><td>Will eventually run out</td></tr>
<tr><td>Solar, wind, geothermal, hydroelectric, biomass</td><td>Oil, coal, natural gas, nuclear</td></tr>
<tr><td>Low environmental impact</td><td>High carbon emissions (fossil fuels)</td></tr>
</tbody></table></div>
<p><strong>Review Questions</strong></p>
<ol class="notes-list">
<li>State the Law of Conservation of Energy in your own words.</li>
<li>Name the energy transformation in each: (a) a waterfall turning a turbine (b) a mobile phone charging (c) a plant making food</li>
<li>Give <strong>three</strong> reasons why geothermal energy is important for Kenya.</li>
<li>A student says "My body creates energy when I eat food." Is this statement correct? Explain using the Law of Conservation of Energy.</li>
</ol>
<hr class="section-divider">
<h2 class="notes-h2">END OF TERM 1 REVIEW</h2>
<h3 class="notes-h3">Summary of Key Topics Covered</h3>
<div class="table-wrap"><table class="notes-table">
<thead>
<tr><th>Strand</th><th>Key Sub-Strands and Topics</th></tr>
</thead><tbody>
<tr><td>Scientific Investigation</td><td>Scientific method, hypothesis, variables, laboratory safety, measurement, SI units</td></tr>
<tr><td>Living Things</td><td>Cell structure, plant vs animal cells, classification (5 kingdoms), vertebrates, invertebrates</td></tr>
<tr><td>Matter</td><td>States of matter, particle theory, changes of state, mixtures, separation methods</td></tr>
<tr><td>Energy</td><td>Forms of energy, transformations, Law of Conservation of Energy, Kenya's energy sources</td></tr>
</tbody></table></div>
<h3 class="notes-h3">Practical Skills Developed</h3>
<ul class="notes-list">
<li>Setting up and conducting a fair test</li>
<li>Measuring length, volume, and mass using SI units</li>
<li>Preparing and observing slides/specimens</li>
<li>Performing filtration and evaporation experiments</li>
<li>Recording data in tables and drawing conclusions</li>
</ul>
<h3 class="notes-h3">Key Vocabulary for Revision</h3>
<p><strong>Scientific Investigation:</strong> hypothesis, variable, independent, dependent, controlled, observation, conclusion</p>
<p><strong>Cells:</strong> cell membrane, cytoplasm, nucleus, chloroplast, mitochondria, cell wall, vacuole, unicellular, multicellular</p>
<p><strong>Classification:</strong> vertebrate, invertebrate, Kingdom, taxonomy, dichotomous key</p>
<p><strong>Matter:</strong> solid, liquid, gas, melting, freezing, evaporation, condensation, solute, solvent, solution, filtration, distillation</p>
<p><strong>Energy:</strong> kinetic, potential, transformation, conservation, renewable, non-renewable, geothermal</p>
<h3 class="notes-h3">Exam Preparation Tips</h3>
<ol class="notes-list">
<li><strong>Theory questions:</strong> Be precise in definitions. Use key vocabulary.</li>
<li><strong>Diagrams:</strong> Label all parts clearly. Use pencil, ruler for label lines.</li>
<li><strong>Practical questions:</strong> State the aim, method, expected results, and conclusion clearly.</li>
<li><strong>Calculations:</strong> Show all working. Include units in your final answer.</li>
<li><strong>Multiple choice:</strong> Eliminate wrong answers first. Read all options before choosing.</li>
</ol>
<hr class="section-divider">
<p><em>Grade 7 Integrated Science Term 1 Notes — CBC Edu Kenya</em></p>
<p><em>Download full notes, past papers, and marking schemes: cbcedukenya.com/grade-7-integrated-science</em></p>
<p><em>Free tutorial videos: youtube.com/@CBCEduKenya</em></p>